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Thanks Brian:

1- Yes, I did watch the LM-1 during the warmup period today. Starts at about 12.1 AFR which is rich, which I would expect during a cold start (from about 75 degrees - not really a "cold" Minnesota start but a Southern California "cold start"). I have a video of this, which I will post shortly.

2- I have not measured / watched the injector pulse width signal through this warmup stage, but that is a good idea. In general, it's very difficult to get a measurement on the "pulse width cycle" - the oscilloscope is a bit difficult to setup if one doesn't use it every day. For the injectors, I've found that I've had to mess with it for ten min to get it to read right. Of course by then, it's no longer cold! I guess I can set it up, save the settings, let the car cool down and then check... Or, I can just borrow an ECU from Steve W. and try it that way. :)

-Wayne

Update from Wednesday:

I'm about three glasses into a bottle of Cabernet, so this will be brief:

I swapped the injectors from left/right. I found some of the gaskets missing in the wire harnesses which made them fit a bit loose. Made some new ones. Fixed the vacuum line. Ran the pump and checked for fuel leaks. Then headed to the store to stock up on some beef and chicken before they run out (they were all out of the good beef). Then came back and started up the car.

Bottomline - NO CHANGE. Still runs fine for two min, and then craps out. Swapping the injectors left / right made no change in the O2 readings on the right bank (cylinders 1-3). I raised the idle using the idle adjustment screw - it idled higher with the same crappiness. I have videos and pics of this, I will post later.

I'm running out of ideas. Tomorrow I will swap out these Magnecor plug wires for the BERU ones. If that doesn't make any difference, then I will take Steve W. up on his offer to loan me a working ECU and test it.

At this moment in time, I would start to suspect a mechanical (engine) problem like cam timing, or chain tensioners, etc. But the car continues to run very well for the first two minutes. So, even if there were something mechanically wrong, I would assume it would show up in the first two minutes. Looking down into the cylinder when I had the injectors out, it looked quite a bit "carbony" in there - the sign of a rich condition. When I removed the plugs a few days ago, I didn't really see much of that. But mucking with the thing over the past several days may have caused some build up. Not sure...

I've already lost sleep on this, and now I'm starting to lose my hair. This is not the most difficult car to work on (the BMW 700 and the 959 take that title, and this car has a ways to go to get to that level), but it's really starting to bug me. John Walker gave his "trouble car" to someone else for a fresh set of eyes to look at, I think I might do the same if I can't figure it out in the very near future. Testing a new / working ECU (thanks Steve W.) will add a tremendous amount of information to the equation.

I've been saying for years that the early Motronic (3.2) systems are my least favorite to work on because they don't store error codes and you need a shelf full of spare parts to test them out and troubleshoot them properly. Carbs are easy. MFI is straighforward. CIS can be slightly confusing, but it's all related to fuel pressures. Motronic is a $%^&**. The later versions (even on the 959) actually store some error codes. Boxsters, 993s, and 996s are a breeze because the computer tells you what's wrong. These 3.2 engines though are the worst! I mean, who actually is an expert on using an oscilloscope on these cars? Probably about .000001%. When the system works, it's pretty good and pretty reliable. But when something goes wrong and it fails, good luck with that.

Tomorrow is plug wire day. Swapping out the Magnecor wires for the BERU ones. I'm not hopeful that this will work, but at least it will eliminate a potential issue.

Anyone want to buy a used 914-6? :)

-Wayne

When the car transitions from cold to warm (and runs poorly), is your o2 sensor connected? The o2 sensor, as you already know, doesn't come on line until its warm.

If the o2 sensor is disconnected (open-loop) and idle is crappy, then you need to trouble shoot the other inputs to the DME. There are only a few - whats the status of your barometric sensor? As far as I know that is the only (non o2 sensor) input that pulls fuel from the base maps. If possible disconnect it while engine is running poorly to see if it is leaning out the mixture.

Also, what AFR is causing your running condition? Are you lean or rich, and why is it differing from the spots you are measuring from?

While you have it idling, you can turn the screw on the AFM (NOT the idle set screw) to lean or richen the mixture. This may give you the truest sense of which side of 14.7 AFR you are on, if the engine running improves.

Don't give up - I think, with all due respect Wayne!! :) that you are making this more complicated than it needs to be. The Motronic system really is straightforward when you step back and look at it. The DME tells injectors how long to stay open and when to fire the ignition, based on load and RPM. The injector time is modified from the base map by oxygen sensor in closed loop, and baro sensor ( and in 964's knock sensing) At idle, load and RPM are disregarded (and the idle switch is telling the computer it's at idle). I think there is also a signal for an AC compressor to raise idle when it's turned on, but I don't believe it affects injector time/mixture.

Assuming ignition timing is ok which can be checked with a timing light ---> your injectors are not delivering the correct amount of fuel.

You've troubleshot the fuel system - seems like normal pressure and assuming correct injector operation. It would be nice to see what the acutal signal (pulse width) the injectors are seeing. If it's a correct signal, it's an injector problem, and if not it's a DME problem. Without seeing that pulse signal, you are using AFR (by way of o2 sensor voltage or LM-1 wideband sensor) as alternative to determine injector opening time.

Something seems weird there, with the various AFR readings you've got. Just like with carbs, engines idle more smoothly with richer than 14.7 AFR than with leaner than 14.7 so my guess is you are lean. You've got to eelctronically 'turn the mixture screw' like you would on a carb to see if you are lean or rich. Your sensors may be reading incorrectly and this would be a way to confirm or disprove that.

As a lot of posts have mentioned, you may have a mechanical problem with a dead cylinder, bad plug etc thats masked by rich running at start-up/cold idle. I think the old trick to pull one plug wire at a time to see how it affects running would help there.

Good luck ! If you have problems like this, where's the hope for the rest of us?

Thanks blyguy. I've gotten deperate and I've started to mess with nearly everything and now the car runs much worse. One should not do this haphazardly, but I've now dialed in and out on the mixture screw, and also the idle air valve in and out. The idle goes up and down, but the car still runs like crap. I'm thinking of taking off the sport muffler and trying to measure the air-fuel ratios out of the open pipes (but my neighbors would not like that one bit).

I just went out and checked all the cylinders with a timing lamp - they all looked okay. I pulled each plug wire. The problem is that the engine is now running so poorly, that simply pulling one cylinder didn't seem to make much of a difference. #2 and #6 made the "most" difference if I had to really guess at it. Same thing with the injectors - unplugging one injector at a time really didn't make it run any worse than it's already running.

On top of all this, my LM-1 meter started recording impossible numbers - 3.64 lambda and 53.5 AFR. I have four (4) spare wide-band sensors so I can swap them out, but I just saw this about 20 min ago and tossed my hands up in the air and came in to have some coffee.


blyguy - I'll answer your good questions in detail:

1- O2 sensor has been disconnected for the past day or two. The LM-1 external air-fuel monitor has been plugged into the O2 sensor port.

2- The barometric sensor is a good guess - I've checked that three times now, I will check it again however. Even with that not operating properly, I don't think the car would run this crappy.

3- Good question. Steve W. thinks the mixtures are off left-to-right. Taking off the muffler and measuring it at the tailpipe would probably reveal more info, but I really can't do that here at home (I'll have to take the car to the shop and do it there).

4- I've messed with the screw so many times now, indeed. The mixture does change, and the car continues to run like crap.

5- "you are making this more complicated than it needs to be" - yes, I agree. At this point, it's such a rabbit hole where I'm just messing with stuff. I've made it much worse, and now have changed and messed with so much stuff that the "change a single variable and measure" techniques are out the window.

With the breakout box I'm checking all of the inputs to the ECU, and they all look good on the surface. With the breakout box, I can test the wire harness, and that is okay too. So, perhaps the problem is with the connector to the ECU or something like that (cold solder joint?).

At this point, I'm starting to think mechanical proble, *but* my gut doesn't really point to that because during the two-minute warm-up phase, the car ran fine - smooth, no misses, etc, able to pull out of the garage fine (now it doesn't and stalls, since I've messed with the mixture and idle so much and have the O2 and idle control valve unplugged). That's where the car is right now - running like crap with the O2 sensor unplugged, and the idle control valve unplugged. I checked the spark plug ignition pattern with the scope and I've also checked it with the timing lamp -> seems okay.

I think I'll drop Steve W. a line and see if I can borrow the ECU he mentioned he had. If the problems persist after that, then I will perform a compression check on the motor. When I got the car back (from being stolen), it had only about 17 or so more miles on it and started up fine (after cleaning the tank and the fuel filter) - it just hunted up and down at idle.

As you mentioned already, I may be overthinking it, *and* again, this is a conversion into a 914, so there's been a bit of weird stuff modified...

-Wayne

still following you Wayne..it is a struggle ...can you think when this all saga problem started?
I have never ever experienced anything like this on Carrera engine....working on these beasts for a long time i had never have to use any electronics tests,oscilloscopes and e.t.c.....
can you go back to the basics?Somehow i`m thinking it is not mechanical problem..since it runs cc.2 minutes perfect...

Ivan

just red through it again i do not see anywhere mentioned the coil...is it black an original or blue or silver...
Also did you already put in the Beru spark plugs wires?

When debugging complex problems, one approach is to have two persons working on identifying the problems each of them see or find in separate individual efforts unknown to each other. Upon completing their individual separate efforts, you bring the two together and see what you got then.

This is how they found a missing nuclear sub that sunk long ago. Many inputs from different areas of expertise.

Just looked at the coil a mere two min ago and thought "I wonder if it's the coil". I have some spares at work (not here at home). But the spark is consistent and level - this doesn't feel like an ignition problem. I've seen ignition problems, they are typically easy to spot - one cylinder runs colder than others.

Indeed, that is the power of the Internet, and in particular these forums. I thought I would have had this licked by now.

I'm going to be borrowing an ECU from Steve Wong this afternoon (he lives around the corner = useful). He also mentioned replacing the DME relay. I've tested it a bunch of times, but I did buy another spare one yesterday so I will check that out. He also mentioned that there are two external signals from the DME that drive the tach - the rpm and the upshift light. He said that the signals are similar, but if you swap them (as often happens with a conversion), one can blow up some components on the DME. Go figure.

My tach does have a problem - it sticks sometimes and you have to tap the glass to get it working. This is a somewhat common problem I've seen with gauges before - my 911 has this issue with a temp gauge, and the 959 also has this issue with the water / coolant temp gauge. Sitting on zero for a long time, they may get stuck. Still, I found in interesting that he mentioned that - I'm going to check the tach connection right now (before I plug in his ECU).

Here are some photos of the (lack of) progress:


Fuel injector holes were not too clean. I scrubbed them with some isopropyl alcohol:
http://forums.pelicanparts.com/uploa...1588887820.jpg

I discovered some of the fuel injection harness plugs were loose, they were missing the little gasket inside (top one is missing, bottom one has it):
http://forums.pelicanparts.com/uploa...1588887820.jpg

So, I quickly made some out of rubber (this first one didn't turn out as well as the 2nd and 3rd one):
http://forums.pelicanparts.com/uploa...1588887820.jpg

Installed:
http://forums.pelicanparts.com/uploa...1588887820.jpg

Here' the car up on jack stands so that I can measure the exhaust temps as it starts up (they were all fairly even):
http://forums.pelicanparts.com/uploa...1588887820.jpg

Just checked the tach. Here's a photo of the back I pulled off of the forums here:

http://forums.pelicanparts.com/uploa...1212102183.jpg

I tested the connections to the tach and both appear to be hooked up correctly (although I've never seen the up-shift light go on):

Pin 1 on tach ---> Pin 11 on the DME (RPM signal)
Pin 2 on tach ---> Pin 21 on the DME (upshift signal)

NOTE: the Bentley Manual is confusing / incorrect on this (pages 240-36 thru 240-39).

Useful info here: http://forums.pelicanparts.com/porsche-911-technical-forum/955931-3-2-motronic-tach-signal.html

-Wayne

Since it's a 914 conversion, have you verified what they're using for grounds? Are they clean and tight?

I checked them all to the negative battery terminal and they all appear to be good. I will triple check the ground strap from the tranny to the chassis...

-Wayne

What about the clamps at the air valve? Are they tight? And since it's a 914, I assume there are plugs in the elbow from the AFM? Are they in place and tight? What about the vacuum fitting on the plenum where the brake booster hose usually goes? And the vacuum lines off of the throttle body are all nice and tight?

Hey Wayne, I know that you had an issue with Loren years ago, but as J.W. says, he knows his stuff, and he's right around the corner. I've been using System C (Loren) since 1985, and we've always gotten to the issue.

It's funny that you wrote this "I have no ill will towards Loren" on your post #57, right after you threw him under the bus. ???????

Also, why don't you just roll it down the hill to Callas? You guys have a relationship. Didn't he help you right your books, supply you with photos etc. Come on Tony, help a guy out.

Ran a smoke test on all of that (three times). Found a very small leak on the first one, and sealed it all up. Should be good...

-Wayne

I didn't throw him under the bus at all. We tried to reach out to him numerous times again and again over the years and the response was *crickets*. This is a free country, and he's welcome to do business (and not to do business) with anyone he pleases. If I thought it would garner a call back, I would give him a ring I suppose, but after 12+ years of not getting calls back, one kindof gives one the message.

I learned that a while ago with some old ex-girlfriends! :)

-Wayne

So, I just did that. Steve W. was kind enough to loan me a loaner unit for the 3.2. Cut to the chase - no improvement. Both my ECU and his loaner ECU react the same. The car runs terrible. I'm beginning to question all of my initial assumptions and I think I'll start over by pulling all the plugs and running a compression check on it when it cools down. That and I will take a look at the plugs (which are new as of a few days ago).

Maybe I'm being fooled by my LM-1 getting affected by ambient air sloshing through this sport muffler?

I did pull the spark plug wires one at a time, and the engine did drop each time. #6 was less pronounced, I'll pay close attention to that on the compression check.

Again, this car was stolen, so who the heck knows what happened to it, maybe someone over-revved it while driving it away. A compression check would reveal that - time will tell if I should have started with that first!

-Wayne

Compression check results:

1- 170 psi
2- 168 psi
3- 175 psi
4- 175 psi
5- 172 psi
6- 175 psi

These results look fairly good to me.

I think tomorrow I will head to work and grab the leakdown tester kit that is there. Then, at the same time doing the leakdown test, I'll do a valve adjustment and change the oil (get back to the basics).

Also:

- New plug wires (this still might be the problem)
- Post photos of the plugs (Some look better than others, I'll probably just use new ones)
- Check distributor alignment with TDC
- Check each injector harness

-Wayne

How about adding a fuel pressure gauge to watch fuel pressure in real time? There’s a tap w male connector M12x1.5 I think on the drivers side.

Good piece of info to swap for a known-working DME, your problem is probably downstream then (fuel supply, fuel injector, less likely combustion chamber or spark since you have assessed those) Youre still in the dark if you are lean or rich- and those AFR numbers are definitely head scratching !

‘Upstream’ changes that modify the DME output AT IDLE are not dramatic like you said. Fuel injection timing based on the crank position sensor/TDC seems to be ok if you have good initial idle- might be worth checking those signals and sensors again to be sure. The baro sensor even at its worst will lean things out but not to the point of poor running. What happens when you rev the engine when it is running poorly? Stumbling, stalling or running rich?

When the valve covers are off, do a cam timing check. Much fun in a 914.

Loren helped me out, a few years ago.
he was most helpful - and a complete gentleman to deal with. he also did it for free ...... actually he was out of pocket a few bucks.
just sayin' : )

I woke up this morning thinking about the easiest way to do that. I think I figured it out. Not really old school, but by using technology, I think I can very simply check the cam timing left-to-right. I can't see the front pulley, so putting a degree wheel on there would be difficult / impossible to use. So, I'm going to hook up two small microswitches to the exhaust rockers for cylinders 1 and 4, and then tie them into the 2 channel oscilloscope, which will record the position as a function of time (while running the car with the starter). The difference in time between those two should be equal. If one cam is slightly off, the difference in time will be slightly longer on one cycle, and then slightly shorter on the other cycle.

I have a drawer full of microswitches (had to buy a 10-pack when I needed one to repair an old robot), so those should work well. The only tricky part will be making sure the switches are mounted at absolute max cam lift and are consistently mounted the same way both on the right and the left. That might be just a little tricky to get 100% right. Worth a try though, and beats trying to do this with the degree wheel where I can't see anything (on a 911, it would be much easer).

-Wayne

Yup, good suggestion -> already done. I left my fuel pressure gauge hooked up and inside the engine compartment. It reads 2 bar every time I look at it...


I pulled the plugs - they look "okay", but some look better than others. I'll post some photos soon.

When I rev the engine, it revs okay, but it does still have that miss. Best described as "random flubbing". It doesn't stumble terribly. In fact, revving it probably makes it run better, as the missing / flubbing is more pronounced at / near idle, and as you rev it the engine has more momentum...

-Wayne

I have not read the entire thread carefully. One thing I wonder if you have checked is the coil. Is it one of the black Bosch German made coils? The silver Bosch coils are total junk.

I had some totally weird running issues with my 3.2 and it it had me stumped until I chaged the coil. Finding the old black German made coil is tough. And finding a coil that is the right voltage and drop in replacement has eluded me. I bought an old used black Bosch coil and all is great.

Hi Glen, i did asked in post 86..did hot hear about it....
Ivan

I wrote in post #89:

The car is running with an original black coil. I have a new silver one on order that I will get today. Although some people do complain about the silver coils, I just called our BOSCH distributor and their return / failure rate on these is 3%, which is not too bad. In past history, I know that if someone has a marginal car (let's say bad grounds or something else off with the system), then the silver coils may be more sensitive to other problems (I.E. they put in a silver coil as a spare or replacement to a black one and the silver one doesn't work, but they may have something else that's marginal).

I jacked the car up and emptied the oil from the sump - looks good. The car has only done a few hundred miles since it was completed, so the oil should still be good. On these air-cooled cars, there's not much concern with coolant leaking into the oil and contaminating it (like there is on the Boxster / 996). I also took a closer look at the lower valve covers - they are nearly completely blocked by the aftermarket headers, so I might check the valve clearances at the top and see if any are off before removing a whole bunch of stuff below. I really don't think the issue is with the valve clearances (the compression check came back okay, and the valve train is not noisy). Checking the top clearances will give me some clues before I spent 4-8 hours adjusting the bottom (for perhaps no reason).

So, today/tomorrow, I'll check the upper valve clearances, check the timing (as best I can), fill it up with oil (important), put on the new spark plug wires, and see if that makes a difference. Then I will try swapping out the coil to see if it makes a difference.

It ignition wires might be a challenge, as I think the Magnecor wires were used specifically because of the different mounting location of the coil.

-Wayne

Maybe this is a dumb question, is there any gas left in your tank?


And if so, when you checked the fuel pressure, have you been monitoring it while you've been testing the car through the warm up phases?

Yes, plenty of fuel in the tank (I believe), and the fuel pressure has been consistently 2 bar.

Come to think of it, when I reinstalled the injectors, the fuel rail was making a slightly gurgling sound - I should run that again for a length of time and see if the noise continues. I figured it was just air trapped in there making its way out because the injectors were recently removed...

-Wayne

Just because I'm slightly bored being at home, and frustrated with the car, I decided to do a quickie left/right cam comparison with the oscilloscope. I mounted a small switch on one of the studs and put it on the tip of the valve adjustment screw. Then I wired this to a 9V battery and sent the corresponding signal to the oscilloscope. I did this for both sides.

The goal is to compare left/right to see if there are any variances. Results? Generally it looks pretty good - there are no major variances - at least ones I think would be causing my problem. I'm not 100% sure though, there are some slight variations, so I think I will dig out my dial gauge and z-block and double check it. Maybe this afternoon after I take a break. On the 914, it's really annoying to turn the crank and get to TDC - you need three hands and a mirror.

Anyways, here's my setup. I initially thought that it would be affected by changes in the valve clearance, but I set that out of the equation by setting the switch to activate only at the very top.

http://forums.pelicanparts.com/uploa...1588975279.jpg
http://forums.pelicanparts.com/uploa...1588975279.jpg
http://forums.pelicanparts.com/uploa...1588975279.jpg

-Wayne

You are really down the rabbit hole Wayne! :P

I watched your video from page 2, where the engine is idling well cold (Lambda is right around 1, equal to AFR around 14.7) I assuming that voltage reading on the multimeter is the oxygen sensor? Oxygen Sensor is cold then starts to dither up to 0.7 down to 0.3 (also seen in the voltage tracing) when engine starts to go lean and run poorly. Then you have this condition where your LM1 is measuring lean AFR and oxygen sensor is reading up and down. There’s a problem with this scenario- your sensors should be agreeing with each other.

You can see that your voltage reading is increasing as the sensor warms up. That’s basically the sensor ‘detecting’ a rich exhaust mixture. 0 V is lean, 1 V is rich. Seems like your sensor is kaput and reading falsely rich.

Hope that is the oxygen sesnsor voltage I am seeing on the yellow meter. The car seems to run nice and can maintain Lambda 1 at cold idle- must not be that broken!

http://forums.pelicanparts.com/uploa...1588986000.jpghttp://forums.pelicanparts.com/uploa...1588986073.jpg

I noticed when you are in open loop (o2 sensor disconnected) everything looks good. Sensor reads 0.5V and you have Lambda 1.0/AFR 14.7. You sensor seems to be reading correctly there (even though it’s not reporting to the DME) Is it the correct sensor? It should be reading voltage below 0.5V when your LM1 is reading lean yet is doing the opposite and reading 0.7V. I don’t think would be possible but is it wired in backwards? I don’t think that would cause this, the sensor detects oxygen gradient between ambient and exhaust. Rich running causes more voltage because of the difference in oxygen level. It’s the intrinsic way sensors work so it can’t be a ‘reversed’ sensor. Have you tried swapping out the sensor?

Fuel injection systems that use an AFM are more susceptible to intake valve leaks reducing the engine intake vacuum in the
plenum causing the AFM to lean the mixture. This becomes problematic as the engine warms-up and Lambda approaches 1.0.
Given that, leak down tests need to be performed on a warm engine. Having a longer intake boot (2X) may accentuate this problem.
Using a scope to monitor the AFM signal (DME pin 7), it may be possible to see variations in the AFM output voltage (spikes)
causing the average output voltage to decrease resulting a lean condition.

Yes, that is very confusing, and making me doubt nearly everything. When running the car off of idle, the air-fuel mixture is pegged at 14.7 (or was in the past, everything is a mess right now).

I took a look at the upper valve clearances (five min). They all seem okay. Since the compression test looked okay, and the upper clearances were good, I'm going to assume that the lower ones are okay for now. It would probably be close to 4-5 hours to check them). Later on tonight, after dinner, if I have energy / motivation, I will install the z-block onto the car, and check the cam timing. I know there's a book somewhere with a fairly decent procedure on how to do that! :)

Then, on Steve W.'s recommendation, I will remove the distributor cap and double-check to make sure that the distributor has been installed correctly. I don't think this is a problem, as it wouldn't show up at idle (more at higher rpm), but since I'm there, I'll check it.

Then, I will replace the plug wires and the coil.

We'll see if that makes any difference...

-Wayne

Okay, I just spent quite a few hours checking the cam timing. It wasn't as "centered" as I would like, but it appears to be correct. It's very, very, very difficult to get the engine to TDC when it's installed in a 914. You have to use multiple mirrors and look at it from different angles (see photos below). You also can't easily spin the engine - but I have a quickie solution for that. Jack up the car, and then chock one of the rear wheels in place with your floor jack. Then put the transmission in fifth gear and spin the wheel to spin the engine. Make sure that you don't spin it backwards. I've used this trick all the time when adjusting the valves on a four-cylinder 914. You can actually get it so that you just take your foot and push the tire to turn the wheel and turn the engine - even easier than using a wrench.

But access is really difficult. I also didn't want to take off the upper valve gasket because these break apart when you take them off, and you can spend another 3 hours just scraping off the remains! And in a 914, the access is terrible. Did I mention really terrible?

Cam timing specs:

0.046" = 1.16mm (cylinders 1-3)
0.054" = 1.37mm (cylinders 4-6)

Spec is 1.1 - 1.4mm with ideally the timing being set at about 1.25mm. Again, it's very difficult to find the absolute TDC for overlap on the 914, and if I'm off by a degree or so each time, it can create some variances. So, these numbers look "good enough" for me to eliminate the cam timing as a potential problem / issue. If they were really, really off, then I would measure again, and use some video cameras to get in there, and also remove the valve cover gasket, etc, and recheck the valve clearances one more time, etc. Then if that still showed a problem, it would be engine out time. But, as I said, these measurements are in spec and they look "fairly okay" to me.

I also checked to make sure the distributor was installed properly (it was). No problems there.

Next it will be buttoning all this back up, replacing the plug wires and the coil.


Dial gauge at .046":
http://forums.pelicanparts.com/uploa...1589071071.jpg


Dial gauge at .054":
http://forums.pelicanparts.com/uploa...1589071071.jpg

Distributor aligned correctly at the line / notch:
http://forums.pelicanparts.com/uploa...1589071071.jpg

My handy dandy Engine Rebuild book for reference (this is copy #1! 17+ years old now!)
http://forums.pelicanparts.com/uploa...1589071071.jpg

Mirror with flashlight, holding iPhone to see TDC:
http://forums.pelicanparts.com/uploa...1589071071.jpg

Slightly better angle for the last photo:
http://forums.pelicanparts.com/uploa...1589071390.jpg

I sponsored a 914 race car for a while. Glued a mirror to the firewall (no sound pad) in just the right spot to do ignition timing.

Well, that's great! Sounds like you'll have solved your running problem once the new plug wires and coil are installed, right?

Wow, I certainly hope so.

Wayne

Are there any hoses that lead from the intake system to elsewhere, such as to a power brake booster, oil tank, etc that could be letting in unmetered air?


Have you checked that both the fuel pressure regulator, and the fuel damper are not internally ruptured and allowing fuel to be sucked in through the vacuum lines? I've found this before on a 964 that prior to was a complete mystery. Are their vacuum lines connected to the correct ports? All the vacuum lines on the back of the throttle body correctly routed? Do you have the recirculating air valve 930.207.222.0X ? Is the thermovalve still on the throttle body and if so what and where are their ports connected to?

All great questions!

- There are no mystery hoses that appear to be going anywhere. When I performed the smoke test, I actually had some issues keeping the rubber cone stuck in the intake because the back pressure was building up. Still, it was odd that I didn't see any smoke coming out of the tailpipe. But I guess that wouldn't happen unless one of the cylinders was at TDC overlap.

- The fuel pressure dampener and fuel pressure regulator are properly hooked up to vacuum, and when they are plugged into the intake manifold, they pull vacuum and change the fuel pressure accordingly. I'm assuming if the rubber diaphragm had failed on these that we would be sucking fuel into the intake (the common failure for these). There's no fuel smell coming out of the vacuum pipe and there is no fuel in the vacuum line/pipe either that I can tell.

- The vacuum lines on the back of the throttle body only go to the pressure regulator and the pressure dampener. The thermotime switch is plugged up as the charcoal canister and other emissions-related stuff has been removed. I thought that the thermotime switch might be leaking, so I did smoke the car when it was warm / hot. There were no leaks that I could find.

Been lazy today, binge watching Netflix with Mom and kids on Mother's Day. Heading out to the garage shortly to install the new plug wires, fill with oil, and test the fuel injector wire harness.

-Wayne

Try an MSD 8222 coil instead of that failure prone bosch silver bullet. Their return rate is probably low because most ended up in the round file.

So, I realize now that the Magnecor wires were probably used because the stock harness doesn't fit too well with the side air flow channel near the distributor. I was thinking this a few days ago. I'll make it work, but there is nothing easy on this car.

But, I did pull off the plug wires and one of the end boots came off revealing a mess underneath. I'm now optimistic that this is the problem (despite me checking the ignition system several times).

Of course, this being a 914-6, the boot from the wire fell off and got lodged behind the distributor where you can't see it! There is *nothing* easy about working on this car!

Take a look at these photos, has anyone ever seen this before? It almost looks like the distributor cap boot or the outside sheath for each wire has melted / fused into the wire itself. Just to see if it was only on one wire, I took another boot off - same thing:

http://forums.pelicanparts.com/uploa...1589147505.jpg
http://forums.pelicanparts.com/uploa...1589147505.jpg
http://forums.pelicanparts.com/uploa...1589147505.jpg

-Wayne

I really see no reason for fancya$$ plug wires when good stock ones work just fine.