Wideband data for 3.2 getting 10 mpg city - what do you think?
 

Engine’s an ‘85 3.2 in an ‘80 911. City mpg is at 10. Highway 27. These results have been double checked. City used to be 18. Drop to 10 mpg occurred at some point during engine's rebuild. Don’t think there’s any need for engine or rebuild details given the wideband data clearly speaks for itself. The issue in hand here will be immediately apparent---O2 delta between 1-2-3 and 4-5-6. Wideband = Bosch 4.9 sensors, Innovate controllers, LogWorks software. To rule out hardware error, sensors were swapped side-to-side as were controllers. Test data remained consistent.

My prior thinking as well as that of others was this being a fuel injector issue. On seeing the wideband data here, and given the injector testing as was done, the finger (in my mind) is now pointing to either the ECU or the injector harness cable. Am interested in alternate views—please see what you think.

I’ll put rebuild notes at the end as I know this matters to some.

Warm engine at idle tests:
Green trace = 1-2-3 side of engine
Blue = 4-5-6
Vertical axis = Lambda
Horizontal = Time in seconds


http://forums.pelicanparts.com/uploa...1731240708.jpg

Idle mixture screw out 5 turns
Lucas injectors
W6DPO Bosch spark plugs



http://forums.pelicanparts.com/uploa...1731243125.jpg

Idle mixture screw out 5 turns
Bosch injectors in 1-2-3 / these are original to engine #0-280-150-158
Lucas injectors remain in 4-5-6
NKG Iridium spark plugs installed



http://forums.pelicanparts.com/uploa...1731243315.jpg

Same config as prior setup only with…
Idle mixture screw now turned out total of 7 ¾ turns


Here's interesting part… The remaining Lucas injectors in 4-5-6 are removed and replaced with Bosch injectors. Engine now has all Bosch injectors… idle mixture remains at 7 3/4 turns out...


http://forums.pelicanparts.com/uploa...1731241119.jpg

Expectation at this point was to see both O2 trace lines nearly overlapping, that being on the potential that the Lucas injectors failed to some degree—and—there being fresh Bosch injectors with even flow now installed. Instead, the wideband pattern of the all-Bosch injectors is uneven side-to-side just as with the all-Lucas injectors. Bosch are indicating richer than Lucas.


More injector detail to consider… Bosch injectors were removed from the engine years ago and shelved. While the wideband system was being installed here, the Bosch injectors were serviced by Mr. Bill. His report…

http://forums.pelicanparts.com/uploa...1731241173.jpg


The Lucas injectors that are now removed from the engine were installed and in service for a number of years prior to the engine’s rebuild. They did deliver 18 city mpg. This fact together with O2 wideband profiles for the all-Lucas and all-Bosch injector config looking similar, and the combo wideband of them being "unusual" in this case… a smoking gun as I see this. IOW.. Injectors don’t seem to be at fault—something else is afoot.

Spark plugs cannot be the cause of the delta anomaly seen but am noting them changed as a matter of record. The switch from W6DPO to Iridiums was advocated by Sal and Ivan---who I credit knowing far more than I about this stuff.

While switching plugs, made sense to test compression. Was done with roughly a 2 second crank and the fuel injection harness disconnected. I suspect cranking longer would result in higher psi. In any case, purpose was to rule out the presence of any cylinder failures. Was good to confirm...TY Sal.

http://forums.pelicanparts.com/uploa...1731241262.jpg

http://forums.pelicanparts.com/uploa...1731241262.jpg

W6DPO plugs that just came out. These were pulled, cleaned, and reinstalled about 500 miles ago when I started into this 10 mpg puzzle. In reality, the color here is more brownish than is seen on my screen.



Engine profile for the interested…

Mods from stock during rebuild:

964 Cams
1.45 matching overlap
SSI Exhaust
2-in-1-out Dansk muffler
Clewette ignition wires
Blaster coil
W6DPO spark plugs

Stock:

Heads rebuilt to spec by Xtreme - new valves & guides, seats faced
Pistons & cylinders were well in spec so all were recycled with new Goetze rings - break in with fossil then replaced with Motul syn 20-50 and new filter.
Polished journals
New journal bearings
Rod large ends rounded and finished to spec with new bearings
New bushings on rod small ends bored to spec
New squirters
New timing chains

Injectors are not stock—are Lucas low impedance—but were installed years ago and so were with the engine doing 18 mpg city. They were “serviced” during rebuild under oddball circumstances. In short, injectors are under suspicion here. ECU is also questionable as the one installed now is NOT the one I used to have pre-rebuild. Won’t get into the saga of these parts as it’s just noise compared to solving the MPG puzzle in hand. Suffice it to say the ECU is also on the suspicious list. Will see about these parts as puzzle-solving unfolds.

After the rebuild and once on the road, power to redline was there through all gears. Were it not for fuel & mileage gauges staring at me, I’d not be writing this. Immediately, and with little Motronic experience I admit, I molested fuel-things hoping for a quick fix. AFM disk, ECU fuel setting screw, mixture and idle screw being included in my initial forray. Varying degrees of performance resulted. Obviously no quick fix was had. As the engine now stands, everything that was molested has been returned to original settings with the exception of the idle speed and idle mixture screws. Warm idle is a steady 850 rpm. Mixture screw is 5 turns out—now changed to 7 ¾.


Did city and highway wideband recordings. That collection is largely redundant so am not positing that stuff. Does exist as good baseline fodder should it be needed.

WOT to redline may be of interest...

http://forums.pelicanparts.com/uploa...1731241445.jpg

This is with Bosch-Lucas injector combo. Did not get to redline in 4th and no 5th at all.

For you who suggested my getting into wideband... you were absolutely right. I regret my hesitation as it now stands. Thank you for egging me on-and-on!
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The W6DPO plugs are not correct for the 3.2, you need standard plugs with normal simple ground strap like these NGK 6637 BPR6EIX Single Iridium Spark Plug
http://forums.pelicanparts.com/uploa...1731361517.jpg

If the stock injectors are causing different reading between banks you likely have a bad flowing injector. I suggest you swap 1-2-3 injectors with 4-5-6 and check AFR again. If the AFR readings swap banks you know it's the injectors.

Be very careful with used injectors, even if they have been cleaned and bench tested they can easily still not work properly in car because of age.

Your idle mixture target should be 0.95 lambda NOT 1.0
The idle mixture is always set between 13.8 to 14.4 AFR

One more point: if you look at the intake you will notice that the throttle body is skewed toward the driver's side, this favors air flow slightly to to 1-2-3 side. Meaning that you get slightly more air flow toward that side, the air is not 100% even between 1-2-3 and 4-5-6 but it's not much different. And if the air favors the 1-2-3 side that would result in slightly leaner reading on that side but what you have shown above is that 1-2-3 runs richer than 4-5-6.

Again, my suggestion is swap stock injectors between banks to be sure it's not injector related.

Then, within the DME it has only one single transistor that fires all 6 injectors at once, I doubt the issue is DME internal. But it could be injector harness related, be sure the big harness plug near the drivers shock tower is clean and tight. Also with key in RUN engine off check the 12volt pin of each injector harness that plugs into the injector. Be sure they all have exact same voltage reading. You can also check that voltage level with engine at idle for each injector, you will need to back probe the injector plugs to do that.

Sal... Iridiums are installed. They went in with the compression tests.

.95 lambda at idle. That was hit with the Bosch injectors in for 1-2-3, Lucas in for 4-5-6 and the mixture screw at 5 turns out. Leaving that mixed injector combo in the engine danced in my head... Couldn't do it, even to just test mpg.

Just spoke with Bill (Mr. Injector) about the injector wideband readings. He leaned toward the situation NOT being injectors but did not take a bold stance on that. Mentioned I'd be sending him the Lucas to see where they are at. He said send the Bosch too and he'd recheck them under warranty. Your idea for swapping injectors is another fine idea. Is on the menu with a wrinkle...

I just sent the ECU to ProgRama in Boca to check it. When it comes back, either it is good as is or there was an issue with it... and Joseph fixed it. If there is a fix, I'll install it and of course wideband it immediately. If ECU checks out good without needing a fix, am swapping the injectors as you suggest.

Injector harness... running 12v through it tomorrow.

By the way, wideband... You played a large role in that happening here. Thank you for the repetition of advice in that regard. More, you're a supernova of all this air-fuel intel. So more thanks your way for raining it down on the arena I'm dancing in here.
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Could there be an exhaust leak? Intake leak?

The last place to send a questionable DME ECM for evaluation! Since scarceller has been very supportive in this thread, he should've been the 1st choice.
From what I've seen of the ProgRama "repairs" over 20 years, it shouldn't have been even considered.

Good Luck!

Also, nothing you showed so far would result in 10MPG city. If anything you should be getting decent MPG running lean in 4-5-6

It's still a mystery, what's the cause of 10MPG?

When you noticed the 10MPG was the stock O2 sensor installed and connected? And now it no longer is in use?

Just noticed you are using a non stock ignition coil?
Blaster coil?

Do not do that, please install a stock coil. The DME is fine tuned to properly charge the stock coil. See my video on what it takes to understand coil charge times and every coil is different.

https://www.youtube.com/watch?v=a7dFdIdsZeU

Not really! The DME ECM just waits a constant time period (~ 1.0 - 1.5ms, spark dwell) before switching-on the output TO-3 Darlington transistor, irrespective of RPM,
to develop the next spark energy. It operates basically the same as a points ignition system, not like the later ignition systems where the time delay for spark energy
development varies based on RPM. Oscilloscope waveforms of the DME ECM pin 1 verify this.


When Blaster coils are used in a 911 3.2, they provide a spark energy basically the same as the OEM Bosch coil, based on their tested parameters as provided here;

Typical Ignition Coil Values: https://www.systemsc.com/diagnostic.htm

As indicated by the coil parameters of the two Blaster coils and the OEM Bosch coil (911 TCI), the electrical parameters are with 10% of one another.
Furthermore, since the coil series resistance is a little higher on the Blaster coils, less heat will occur to the DME ECM output transistor coil driver
when coil current saturation occurs.

Not correct, the DME has a 3D spark dwell table and varies spark duration per crank rev based on system voltage and RPM. the table looks like this:
http://forums.pelicanparts.com/uploa...1731590367.jpg
I have tuned this table for different coil types in the past.

Is the blaster coil similar to the stock coil specs, that I don't know but I take your word for it. Or one could bench test it to find out the exact time it takes to fully charge and saturate the coil and various voltages.

Joe... could be but doubt it. Intake nuts were changed a few months ago to narrow nuts and torqued. Exhaust I checked a few weeks ago but not all of them. On your note, will check them all to confirm one way or another.


Thanks Dave. At this point, what's done is done. Will see how they handle my case. Sal's been beyond supportive, more than anyone knows from this and the prior "disk turn" threads. You too have helped a great deal---albeit you have a heavy hand at times! Had I known Sal worked on ECUs, would have been no-brainer to put it in his hands. Now I know. Had conversation with him about this yesterday after seeing your post. (Login was glitching for me yesterday.)


Sal, when 10 mpg was discovered, that was immediately after rebuild. Stock narrowband was installed at that time. In the prior "disk turn" thread dealing with this matter, input to me was that 3.2s don't need the O2 sensor connected. I doubted this and so disconnected my sensor and checked milage. No difference. It has been disconnected since. Now, wideband 4.9s are installed. I have not run a formal mpg test but can tell from the fuel gauge and odo that the same 10 mpg city continues.

Whether the imbalance side-to-side is related to 10 mpg or is a separate puzzle is also unknown. Am prioritizing solving the imbalance. Perhaps the 10 mpg will solve with it / perhaps not. I hope the ECU is at fault for both issues!


Yes on using Blaster coil. I tried to get a "black" Bosch coil during rebuild as the news was to avoid the silver-cased coils. Supposedly the "silvers" were made in SA and inferior. Black Bosch coils were NA at the time. Checking Blaster specs to the stock Bosch, specs matched so I didn't hesitate to go with the Blaster.

Setting mpg and O2 imbalanced engine sides aside... engine idles well and pulls with power to redline through the gears. I say this as reference while not knowing what difference would be evident between running a Bosch or Blaster coil.


Am on the sideline interested to see where this coil discussion goes.

If anyone has a source for the original black Bosch coil, please post it.

Should be hearing from Joseph at ProgRama today or tomorrow.
.

Karl, just curious to know if you are now running open loop or closed loop. If closed loop, since you now have a setup with two wideband sensors, which one of the O2 controllers did you plug back to the Motronic ECM? And have you tried to swap them? It is probably a stupid question, but since the Motronic only has one input for the return signal, just asking anyway.

Tested injector harness for integrity yesterday. (This should have been done before sending ECU out so am guilty---cart before the horse here.)

http://forums.pelicanparts.com/uploa...1731594844.jpg

http://forums.pelicanparts.com/uploa...1731594669.jpg

Pin 14 serves 1-2-3 side of engine. Pin 15 serves 4-5-6. When looking into connectors to injectors, and with connector's quick-release bar facing down, full continuity runs to right side female slot.

Harness is good --- 12.64v from ECU plug to all 6 injector connectors.
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Gilles... Way I set dual wideband up here is to see & record O2 data using LogWorks. No controller is connected to ECU so engine is now constantly open loop in regard to O2. Early on in this expedition---in the "which way to turn..." thread that I recall you were a part of---there was input that a 3.2 does not need the closed loop provided by a connected O2 sensor for the engine to run correctly. I checked this proposal by disconnecting my O2 sensor and running a mileage test. No difference in mpg or performance with or without the O2 sensor connected. Given my 10 mpg city, perhaps this discounts the credibility of my engine's results in this regard. That said, given the credentials of those who offered this input, I doubted only because I'm an empirical monger.

I did swap the O2 sensors side-to-side in the exhaust after seeing the first trace lines... (green is 1-2-3 side / blue is 4-5-6, scale is lambda.)

http://forums.pelicanparts.com/uploa...1731605553.jpg

Had to question if imbalance seen was a sensor or controller fault or truly the exhaust O2 levels. I also swapped the Innovate controllers. Readings did not change for each side of the engine. I concluded hardware was working correctly.
.

Karl, one more thought after seeing this chart. The lean side has some spikes in it as well as being higher. Could this be a leak somewhere on the intake side? A crack, gasket, hose, or something else?

I may be overlooking this answer, but could the DME be reading the lean side to over correct fuel dose and driving down the mpg? You probably wouldn't feel this in the power of the engine, but it would definitely show up in fuel use.

These engine do not like to idle above 1.0 lambda they will lean misfire at idle if lean. That's likely the cause of the spikes in lambda on the 4-5-6 side. The green line for 1-2-3 looks like decent lambda around 0.95 and that's a good setting for mixture.

The mystery still is why are the 2 banks so different?
My suggestion is swap injectors from RHS bank to LHS and see if the issue moves to other side. If it does it's an injector issue, if it does not you likely have a air leak on the 4-5-6 side. I really suggest swapping injectors and using only the stock injectors.

The other test worth while is a cyl balance test unplugging one injector at a time and observing what that does to AFR, if one injector effect AFR more than another sister injector on that same side you know that cyl is having an issue. Also spark plug color is worth looking at. The WBO2 data is ONLY one data point, you can't put all your faith in just one data point. For example: maybe you have a air leak at the head gasket in cyl 4? that would make you think the entire bank 4-5-6 is lean but it's not, you may have 5 and 6 running on target and only 4 is lean because of a cracked plastic spacer or gasket at the intake port. Remember, the WBO 2 sees the average O2 in the exhaust stream from all 3 cyls :)

One more thought, double check firing order of the dizzy and be sure the spark cables are going to correct cyl. Firing order is 1-6-3-4-2-5 (clockwise rotor rotation). No disrespect here, but I've seen stupid things cause issues in the past :)

Also the 964 coils are exact same part number as the stock 3.2 and you can find plenty of used good ones on ebay :) and you get 2 coils for a decent price. They are the good German black ones, just search for "porsche 964 coils" I see a set of 2 right now for $49

Enjoy!

Actually, the spark duration is basically a function of the spark energy stored in the coil during the time the Darlington transistor output pin1 is initially not grounded, typically about 1ms on the 911 3.2.
So at 6K RPM with a spark duration of 1ms, this leaves about 2.3 ms to charge the coil for the necessary spark energy.
Once one knows the key parameters of an ignition coil, no actual in circuit testing is needed.

Checks just completed...

• All intake nuts. All tight. Replaced barrels with 10mm nuts after rebuild. Find these easier to deal with...

http://forums.pelicanparts.com/uploa...1731617540.jpg

• Rubber sleeve joining manifolds. Loosened and looked all around sleeve. This has bias towards 4-5-6 so a leak here??? ...Was tight. No cracks in rubber. Mating surface on manifolds are without blemish.
  
• ICV rubber. Not a contender for 4-5-6 but right in hand. All hoses are pliable and connections are tight.
  
• Intake manifolds. Cleaned & inspected during rebuild. I know they are not cracked and flanges to heads are all flat, aligned, and without blemish.
  
• Ignition wires. All oriented on dizzy correctly and run to where they belong.

Cylinder balance... that will happen when ECU's back in service. Results should be interesting.

Arriving tomorrow is a narrow wall 12mm socket. This is to fit into the channels in the SSIs that lead to head nuts. With the engine out and flipped over, it's one thing to access these nuts. Laying below the installed engine it's another. Regular 12mm socket will enter the channels but there's a seam at the other end that prevents regular socket from making complete passage. Fiddling with putting socket on an extension that's passed through the channel... not worth saving a few dollars now. I'll check exhaust nuts when narrow socket's in hand.

Must be closing in on what ails this engine.
.

Thanks for 964 coil info Sal.

One other concept that I don't remember if it was mentioned is if you have a misfire, or dead spark on a cylinder it could cause your lean measurement even though you may have the correct fueling. an O2 sensor only measures oxygen content in the exhaust stream, so if you have uncommuted fuel with the associated unburned oxygen you will have a lean reading on the WBO2.

this may also account for the poor fuel economy, since you will be spending fuel that is not generating the associated amount of work.

Had this, pin hole leak below the spark plug wire dustboot so couldn't see sparks at night, partial spark on one cylinder caused the O2 sensor to feed more fuel to hit 50%.

How are the ground return paths for the left and right side injectors? I read you checked the signal, maybe I missed it.

Phil

There is no real ground for injectors. They are permanently powered on one side (+12V) and their other side is the driving signal from ECM, which is a pulsed ground signal with spikes to open and close them.

76... I've not looked at each plug's spark. What's been relied on is plug appearance together with engine's performance. Have had a 5 cylinder 911 under foot. Drivable but relegated to sloth mode. Well said on uncommuted fuel. Is a curious topic given Porsche including a single O2 sensor (for 3.2) and some having disconnected it.


Phil... I tested injector harness for a potential fault that would cut the signal to any injector(s). Ran 12v through the circuit for each injector and harness is good. Ground in this case was the test battery's ground. Gilles has elaborated on injector's working ground.

Just finished checking vacuum hoses & connections. Roughly 90% of the hoses are relatively new. Ones that are not, they're not brittle. Fuel feed system on engine was refreshed and customized with a spin-on fuel filter in 2020. No problems with that system. Flow & pressure at the rail have been tested. Engine with the new fuel feed did deliver 18/27 mpg pre-rebuild. (27 highway am not historically 100% sure about but know it was in twenties. 18 city I'm positive about.) "Does not exist" is due to 3.2 Motronic engine being with '80 oil tank.

http://forums.pelicanparts.com/uploa...1731691492.jpg

With the maniacal focus given the engine during the rebuild, thought I had every connection done without leaving a doubt behind. Am eating crow here... found a loose clamp ("L") on the brake booster circuit. Were it not for repeated "air leak" comments, I'd not have checked this circuit. Thank you to anyone who mentioned "air-leak." This find is to your credit. Is this loose clamp the holy grail here...?

...This would allow some measure of air to bypass AFM. And I think there'd be a bias of flow into the 1-2-3 side through the booster vacuum passage in that manifold. If so, there's more air entering the engine than the AFM knows of and with the bias 1-2-3 side should run lean. The opposite is the case... 4-5-6 is the lean side. If I'm not mistaken, added air and no O2 sensors (telling the ECU of this condition as is the case here) would lead to improved fuel mileage and not necessarily a good condition for the engine---too lean. Yet the opposite is being proven at the fuel pump. The odo was confirmed being accurate from the get go.

Have yet to check exhaust nuts. Temp gun brake discs to check if any are dragging. And ECU remains in question. With loose clamp now tight, am eager to get ECU reinstalled and trace the engine to see where lambda is with this change in condition.
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The leak you found at the Venturi Tube is not likely the case for the issue. As you mentioned it would cause 1-2-3 to read lean and you have the opposite. But nice to fix this anyway.

Please do these 2 next:
1 - Double check ignition cables and firing order, I've seen crazy things in the past.
2 - Swap injectors between banks and recheck AFR, trust me on this one, it's important.

As mentioned, injectors have 12v at all times on one pin. Then the other pin goes back into the DME via DME Pins 14-15 then internally in the DME those pins go to one single transistor and that transistor applies ground to the injector. The ground is applied using peak-and-hold method. This means it's a ground pulsed signal, can easily be seen using o-scope.

I highly doubt your issue is the DME nor it's wiring. I really suspect air leak, faulty injectors or some other mechanical issue causing the lean out on 4-5-6 side.

Correct, and a cyl balance test by simply unplugging an injector one at a time can easily find the cyl not firing.

I’m not sure if you’ve already tried it,
… after a short drive to warm things up a bit, get under the engine with your temp gun and try to get a read on each exhaust pipe where it exits the head, or at least a temperature on each cylinder. This will quickly show if one or more cylinders are not firing.

Sal, you may want to edit your post and swap 3 and 2 in the firing order. Someone might read it and think this is the firing order to apply. ;)

Updated to do:

- Exhaust nuts - Ordered narrow wall 12mm socket and 9/16"is received... redo.
- Cylinder balance / disconnect one injector at a time and compare wideband traces
- Temp gun on down pipes / ErrorMargin... this was done with Lucas injectors. Will do again with Bosch injectors now installed
- Temp gun on rotors / check is for dragging brake related to 10 mpg
- Recheck ignition cables / firing 162435 - Correct connections at distrib and plugs
- Swap injectors side-to-side

Engine is disabled for time being with ECU sent out. Exhaust nuts and recheck of ig cables will do today.

Ignition parts just tested for resistance…

Clewett spark plug cables end-to-end
multi-meter @ 20k ohms

1 = 0.51
2 = 0.56
3 = 0.60
4 = 1.31
5 = 1.33
6 = 1.64

Blaster coil

Primary @ 200 = 1.4 - mm resistance @ 200 of 0.7 = 0.7
Secondary @ 20k, both = 6.14 (no mm resistance reading @ 20k)
Case grounding to circuits @ 2000k = none

Distrib & rotor

Cap’s coil lead (center pole) outside to inside @ 200k = 0.8
Each circuit in cap (inside rotor contacts to outside leads) @ 200k = all 0.8
Rotor’s center point to outside contacting edge @ 200k = 0.8

http://forums.pelicanparts.com/uploa...1731961588.jpg

Distrib was rebuilt, shimmed, and lubricated aprox 2 years prior to rebuild. Where I am, if this dries out---it's getting close---it rusts quickly.


http://forums.pelicanparts.com/uploa...1731961982.jpg

Ig cables were rerouted in 2020. Did so to see top of fan housing absent that hardware. Emptiness that resulted came with a price—is more complicated to deal with covert cables whenever needing to do so. Having fiddled with ig cables a number of times during this MPG expedition, was time to do something...

http://forums.pelicanparts.com/uploa...1731961643.jpg

ID collars added to all cable-ends. Simple / works nicely. Benefit is mainly 4-5-6 side but is now altogether easier. Rotting fuel lines were dealt with in 2020. Never fond of changing stock fuel filter. New fuel run was designed including spin-on. Not simple / works nicely. Filter head cnc'd by Xometry. Fine job they did. Jim is credited with the spot on CAD files that went to Xometry. Thanks Jim.

ECU inspection news is just in and it's not good. Unit tested in working order / no faults—according to ProgRama / Joseph. Given wideband data to date, I was thinking there was a signal fault to the injectors generated in the ECU. That would have been the problem and onto fixing it. And so my disappoint in "no faults." Sal has held it not being the ECU but I had to check it. (There's a sordid novel behind this ECU.)

Hit list when ECU is back---and after exhaust flanges are checked for tightness:

- Cylinder balance / disconnect one injector at a time and compare wideband traces
- Temp gun on warm engine down pipes. This was done with Lucas injectors. Will do again with Bosch injectors.
- Temp gun on rotors / check is for dragging brake related to 10 mpg
- Swap injectors side-to-side and compare wideband traces

.

Continued...

Exhaust manifold nuts = All tight


ECU

Fuel injector signal issue did not appear in ECU as I thought was a possibility. Nothing wrong with ECU according to bench test by ProgRama. Am a bit surprised they did not---in the least---attempt to upsell me. Or, find ANY fault.

If you're wanting to bench test your ECU, speak with Sal. I didn't know Sal did this or I’d have gladly sent my ECU his way rather than to ProgRama.

Receipt from ProgRama:
http://forums.pelicanparts.com/uploa...1732715146.jpg


Altitude sensor

With this sensor disconnected or connected… no difference in O2.


Cylinder balance

Disconnecting one injector at a time starting on 1-2-3 side…

http://forums.pelicanparts.com/uploa...1732715223.jpg

Is immediately apparent I f’d up the ID color codes (in LogWorks.) They’re flipped. Am eating crow here. Apologies for this. Doesn’t change solving 10 mpg or the imbalance. Does change the interpretation of when the Bosch-Lucas injector combo was running/tested. Correctly diagnosed, it is the Bosch injector side (1-2-3) that shifted richer and into near alignment with the Lucas side (4-5-6.) This injector combo with idle mixture screw at 5 turns out has resulted in most aligned O2 readings to date.

Were it not for Sal suggesting this balance test, ID error may not have been discovered. Thank you Sal. With IDs now corrected…

Green = 1-2-3
Blue = 4-5-6
Engine at warm idle
Mixture screw currently 7 3/4 turns out

http://forums.pelicanparts.com/uploa...1732716315.jpg

http://forums.pelicanparts.com/uploa...1732716809.jpg


Newly installed 4.9 sensors

Have another pair of Bosch 4.9 sensors on the shelf. Just installed them in place of 4.9 sensors that have been running.

Idle mixture screw was turned fully in and is now 5 turns out. Engine @ op temp…

http://forums.pelicanparts.com/uploa...1732716315.jpg

7 3/4 turns changed to 5 turns (idle mixture screw) makes a difference. Spike = #1 injector disconnected/reconnected.


Rotor temps

Car was roll-tested at the outset of 10 mpg puzzle solving. Was easy hand-push and car came to gentle stop. I subsequently took brakes off the menu. Was suggested to temp-shoot the rotors… good idea. Shot them twice, each at a different stop. Temps in dF.

LF: 96 RF: 99
LR: 111 RR: 221

LF: 100 RF: 117
LR: 128 RR: 136

Delta between LF and RR seems out of place.

Notes: Under hard braking, no pull to either side. Mintex pads, drilled rotors, flushed system and new fluid installed when engine rebuild was in progress. Brake drag brings up…


Hand/parking brake

Very rarely do I use parking brake—handful of times a year if that. Always park car in gear. Just checked: set hand brake and car would not budge. Released hand brake… car would not budge. Backed up slightly and brakes released. Then hand-pushed car… easy and rolled to gentle stop. Call hand-brake a potential 10 mpg contributor, perhaps along with wheel bearings. After posting this, am diving into the rear drums and checking all bearings.


Down pipe temps

http://forums.pelicanparts.com/uploa...1732715778.jpg

There are temps here from a few weeks ago (when the Lucas injectors and W6DPO plugs were installed.) A second set of temps were taken yesterday (with the Bosch and Iridium plugs in.) All temp taking sessions are at random moments. Gun shots are always aimed just above the heat exchanger collar and on the naked down pipe near the flanges. Aim is at apex of pipe’s curve relative to where the gun is. Moving aim even slightly left or right of apex alters readings—so none of these temps should be considered precise. “Ball park” is more appropriate.

Below are the numbers charted above.

Temps taken in 7.24 - Lucas injectors and W6DPO spark plugs:

3 520 6 481
2 521 5 515
1 524 4 457

3 497 6 484
2 445 5 472
1 423 4 442

Temps taken now 11.24 - Bosch injectors, Iridium spark plugs:

3 305 6 377
2 290 5 358
1 283 4 316

3 515 6 521
2 485 5 541
1 501 4 510

Fuel

Have run Shell exclusively for years. Is not a brand preference, rather it is the station’s location that works best for me. 98% of time I’ve filled from this same location.

Now, tank has been run empty and filled at Westar, 22nd & Coral Way. City mpg test in progress. Engine config running with this new fuel brand:

• Iridium spark plugs - took place of W6DPO
• All Bosch injectors - took place of Lucas
• Clamp at brake booster Y tightened - found loose
• ECU handled by ProgRama - benched / no faults found
• Idle mixture screw now 5 turns out - was most recently 7 ¾ turns out - did not keep track of setting for early mpg tests.

Lucas injectors

On their way to Idaho Bill for testing. Given earlier results with Bosch-Lucas combo installed and idle mixture at 5 turns out, when Lucas return, am going to put Lucas back in 4-5-6, leave Bosch in 1-2-3 and run city and highway mpg tests. While this may not be the fix for 10 mpg, it may—oddly—resolve the imbalance.


Still on test menu:

Swapping injectors side-to-side
Parking brake inspection
Wheel bearings

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http://forums.pelicanparts.com/uploa...1732739913.jpg

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Left side parking brake. Looks guilty. Mostly the hub.

City mpg test in progress is contaminated with this work. After both sides are rebuilt, will restart city run. Get to right side tomorrow. Discovered these drilled rotors have no adjustment hole in hub. Complicates things.

Bearings on front left feel good. Wheel spins freely. No axial play. Did not get both sides of azz end in the air to check rear bearings.

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Karl, I just looked at the results from cyl balance test and cyl 4 and 5 are under fueling! That's why the blue line averages out and runs lean.

Swap the injector from bank to bank and test again.

If you look at the blue line results you can see that inj 4 and 5 did NOT lean out mixture as much as the other injectors did. This points to those 2 cyls 4-5 running lean and most likely it's the actual injectors in 4-5.

Swapping them will prove this. You could also just swap 4 with 6 and that way you only mess with one fuel rail.

And injector 4 is the worse of them all.

Hope I'm making sense here.

The temps on the brake rotors seem to indicate a possible issue, how old are the brake hoses? A collapsed brake hose will cause a rotor to drag because it can't allow the brake fluid back out of the caliper. Keep that in mind.

Sal... I see it. Makes sense. Swapping 4 and 6 Friday.


Soft lines were replaced a number of years ago. Will take a close look at them tomorrow while also dealing with RR parking brake rebuild. Thank you Sal.
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From my notes, #4 cylinder has the replacement injector I got just prior to reinstalling the original 5 Bosch 158s. Bosch installed in place of Lucas. #4 inj is supposedly also 158. Bosch part number is on the neck like the original 5. What sets #4 apart from the rest is the metal prong at the discharge end---not sure what the correct name of that thing is. That "prong" is thinner that the rest of the inj prongs. Idaho Bill tested all these Bosch injectors including the replacement in #4... and approved them all. To move forward, I went with it.


Charted rotor temp numbers. Will be taking RR apart this morning. And looking at all the soft lines.

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No soft line receipt found in my records last night. Sometimes parts come from friends---trades---in which case there's no paper trail.
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