Normally, I would agree 100% with you, and that's pretty much what I've done so far. But my cost on a new tank from Dansk is a whopping $160, so I got one and I'm going to just stick it in there and eliminate that as an issue. If the tank were much more expensive (like $800-$1000) then I would think twice, but it's so cheap, that it's not worth really mucking around and maybe leaving something odd trapped in there.

-Wayne

IOW it ain't worth the time to try it! Good call. I was thinking a tank would get a little out of hand.

Just spoke with Brooks Brown, our rep there at Mesa Hose. He said they just had a set of these done that went out the door today. He said remove them from the car and send them in. I am going to try to get the tank and the lines out today. Jacking the car up and dumping gas on my face is not something that I'm looking forward to at this moment.

-Wayne

Smoke a cigar and make it interesting Wayne!... no sense of adventure man! :D

Okay, got it out. Wasn't too bad. I installed a high volume flow fan into the garage a year or so ago, and that has helped tremendously with the cars being in there. I typically just leave it on all the time.

Discovery: there's rust in the tank for sure. I've seen better, and I've seen worse. This one doesn't look too bad to me actually, but maybe there was a *lot* more in there before and it may have not gotten all flushed out. The tank is out in the sun, evaporating the fuel out right now, I will take a look later on to see if that is just surface rust or actual sediment. Not a super-hot smoking gun, but a very close suspect here. As everyone else mentioned as well, it's a good idea / good time to replace all the fuel lines.

Question: The 914 has a supply line and a return like for its fuel injection system, just like the 911 CIS and Motronic, etc. On the 914, the tank return line input is very tiny compared to the supply line. I'm not sure of the answer and I haven't done any research either, but perhaps someone here knows off the top of their head what the side of the one on the bottom of the 911 3.2 tank looks like? I want to make sure they are the same (it looks like it would be very easy to drill this out slightly larger if needed).



Thanks!


Here are some photos:


Connections under the tank:
http://forums.pelicanparts.com/uploa...1589935788.jpg

Fuel pump:
http://forums.pelicanparts.com/uploa...1589935788.jpg


Brand new tank - looks great!
http://forums.pelicanparts.com/uploa...1589935788.jpg


Original fuel sender, dated 1973. I thought I replaced this like 25 years ago, but maybe not:
http://forums.pelicanparts.com/uploa...1589935788.jpg


Connections on the bottom of the tank:
http://forums.pelicanparts.com/uploa...1589935788.jpg


Here's that fan I mentioned, very useful:
http://forums.pelicanparts.com/uploa...1589935788.jpg


Nice to have a skinny wrist to be able to stick it inside the tank (just barely):
http://forums.pelicanparts.com/uploa...1589935788.jpg


Fittings look to be in poor condition:
http://forums.pelicanparts.com/uploa...1589935788.jpg

If the size of the fuel return line were inadequate, the system fuel pressure would be too high.
Given the number of times the fuel pressure has been checked, a restricted return line is not one of your problems.

The pressure was a little higher than the spec, like 2.7-2.8 bar when it should have been 2.5. I'm going to compare the pump flow rates from the 914 fuel injection to the 911 fuel injection to see if they are similar / comparable. If yes, then it's probably not a problem.

Thanks!

-Wayne

Always finding more issues - the filter screen is completely worn away / dissolved. I guess this wasn't looked at when the new fuel lines were added. The remnants of the filter screen are still slightly attached.

-Wayne

http://forums.pelicanparts.com/uploa...1590006860.jpg

Update / plan:

- Have the new gas tank, it's the wrong one of course, and the correct one won't be in until about August. Still, this one might work - I just need to make / modify a bracket to hold the expansion tank. Should work, but it's just yet another thing.

- Took all the gas lines (eight total) to Mesa Hose, and they are going to be remaking them out of teflon, as per Steve W.'s suggestion. Those are due back on Tuesday. The only lines that remain in the car are the center tunnel lines, which are steel, I believe (I replaced them with steel 25 years ago, but when the conversion was done, the builder took the supply line out and replaced it with a larger diameter line, which I still believe is steel). I will blow those lines out, and I'll also run some isopropyl alcohol through them. The car is in my garage at home, and I don't really have the capacity to do much more than that.

- The engine has a bit of carbon buildup which I will be picking away at over the next few days.

- The injectors and fuel rails are out being cleaned and tested.

- The new air flow meters arrived this week. I also ordered a new adapter for the KN filter that eliminates that extra 90-degree bend. I'll have to fabricate some brackets for that.


That's it for now...

-Wayne

Break out a bore scope and have a good look around in the tank. If it doesn't look too bad, do a good rinse and put the thing back in. Get that puppy crankin!!

Brief update:

- Ordered new parts to re-orient the air filter / air flow

- Installed new plugs, routed the BERU wires properly

- Sent the injectors back to RC to have them take a look. One was completely non-functional! We'll have to see if this one continues to give problems. I tagged each injector with a different color zip tie so that I would not get them confused. I looked at the mini filters that are integrated into the injectors - I didn't see any filters that looked super clogged. This is both good and bad. Hopefully the injector will not act up - if it does, I will probably go ahead and replace all of them.

- Got the new AFM from Autobahn here in San Diego. This is a take-off unit from one of the Singer 964s. I tested it using the oscilloscope - works fine. Also drilled out the plug (never did that before). The plug is interesting, it's aluminum with a steel bottom to it, so that you can't damage the unit. I've never quite seen something like that before.

- Waiting to get the fuel lines back from Mesa Hose (hopefully tomorrow). Then the reinstall of all of this stuff will happen. It will probably take a day or two, depending upon how much I get distracted.

Photos:

Fitting up the air flow meter with the new brackets:
http://forums.pelicanparts.com/uploa...1590448690.JPG


Here's my new filter, elbow, and mount (that I still need to modify slightly to make it fit). Spectre Performance made the elbow, the mount, and the connector (clamps not shown). Seems like okay quality stuff - all bought on Amazon.
http://forums.pelicanparts.com/uploa...1590448758.jpg


Newish AFM from the 964:
http://forums.pelicanparts.com/uploa...1590448758.jpg


Testing the new AFM -> Looks good!
http://forums.pelicanparts.com/uploa...1590448690.jpg


AFM test - power in, ground, and the signal to the scope:
http://forums.pelicanparts.com/uploa...1590448690.jpg


Wiring diagram for the AFM:
http://forums.pelicanparts.com/uploa...1590449527.jpg


Another big, long test on the AFM (slowly moving the flapper):
http://forums.pelicanparts.com/uploa...1590448690.jpg


Another shot of the new Air Flow Meter (AFM):
http://forums.pelicanparts.com/uploa...1590448690.jpg


Injectors back from RC. I thought my idea of using colored zip ties was pretty easy and clever. So, I didn't have to make labels 1-6:
http://forums.pelicanparts.com/uploa...1590448758.jpg


The internal filters inside the injectors (did you know there's an internal filter inside each injector?) - these looked okay, not completely gummed up:
http://forums.pelicanparts.com/uploa...1590448758.jpg

Injector report showing a bad #1 injector!
http://forums.pelicanparts.com/uploa...1590448758.jpg


Cleaning up the engine bay and the ignition wires, reattached the air guide carefully to avoid contacting the wires:
http://forums.pelicanparts.com/uploa...1590448758.jpg


Other side, cleaning up the wires:
http://forums.pelicanparts.com/uploa...1590448758.jpg


I'm going to replace this while it's out of the car too:
http://forums.pelicanparts.com/uploa...1590448690.jpg


Organizing:
http://forums.pelicanparts.com/uploa...1590449527.JPG


More organizing:
http://forums.pelicanparts.com/uploa...1590448690.JPG

I know this isn't your first rodeo, but hat's off to you for perseverence!

Fingers crossed it was a fuel contamination issue.

Nope, not the first rodeo, but I'm gettin' old, and this bull is kicking hard!

-Wayne

Wayne,

The AFM mount up is much better now, nice job. Is that a S&B Air Cleaner? If so those are top notch! They also have a version called Power Stack that has intake element even of the top of the filter.

The flow numbers for the injectors also look good now, I bet your AFR numbers will be far better at warm idle.

This is a power stack S&B air cleaner, they are custom made to spec, you chose dimensions from a catalog. I've used these for years:

http://forums.pelicanparts.com/uploa...1590517714.jpg

That is pretty neat. No, mine is not as Gucci as those, but this time I did size everything correctly and I fabricated some nice custom brackets to hold / suspend the filter using the stock mounts - used an old muffler clamp that I found - drilled a hole in it, and mounted it using a rubber grommet and an existing S-shaped bracket. I also tied the AFM into an existing boss on the manifold. I was surprised that this seemed to work fairly well on the first try, but of course, it's not in the car quite yet!

-Wayne

(VEX Robotics table in the background, if anyone is trying to figure that out...)

http://forums.pelicanparts.com/uploa...1590524056.jpg

Were there angels singing when that pic was taken? There should have been.

You may have already checked this but make sure the fuel line is not touching or near a heat source.
It may be that the fuel is being heated to causing vapor to form in the line.
As a precaution you should heat shield or insulate any exposed fuel lines.

carrera 3.2 going lean and misfiring
 

Hi Wayne,

I had a similar problem on my Boxster 2.5 flat six. It turned out to be a faulty vario cam solenoid on bank 1. I replaced the solenoid and the engine has since been performing perfectly

Though my 914 is a 4 and has dual 45mm carbs, I had a problem where there was just enough kink in a fuel line where it would flow enough gas for low speed cruising, but when I'd try to accelerate hard, the kink would make the car run out gas. I would take a look at the location of the fuel pump, the lines going to it from the tank, including the return line, and make sure that fuel flow isn't being restricted. Also, is your pump mounted at the front near the tank or at the rear near the engine?
Enough fuel might be filling the lines to make the car run for 40 seconds before it essentially runs out of gas due to a pump issue or line restriction.

I had a similar problem with my Boxster 2.5 The misfire and leaning out was caused by a faulty vario cam solenoid { in my case on bank 1} I replaced the solenoid and the engine is running smoothly with no problems

Sounds like thermo switch is bad . On cold start the valve doesn’t operate . After a minute or so it starts to operate. When in operation it induces vacuum flow . On the switch is a tiny cap, about 1/8 dia. If the cap is missing it wil cause a vacuum leak. Switch is located at the base of the throttle body . Good luck

Boy, this thread reads like an enthralling murder mystery! I find myself creeping up on the edge of my seat in anticipation that each new post will drop the smoking gun big reveal. Like Tiger King, I don't think this thread could have been better timed.

Kudos to Wayne for the perseverance and to all the contributors, including many of the forum's top dogs. I love seeing both Steve W. and Sal chiming in as 3.2 Carrera whisperer brothers from other mothers and opposite coasts, especially as Sal is advising on my 3.4 '87 build and Steve tuned my '88 on the dyno.

Steve tuned my '88 on the chassis dyno at Gameface Motorsports. While I was there, I noticed their engine test stand. Several times during this thread I've thought that I would have given up on trying to diagnose this with the motor in-situ, pulled it and have Sergio run it on the test stand.

Anxiously awaiting the next installment of this serial.

http://forums.pelicanparts.com/uploa...1590591935.jpg

http://forums.pelicanparts.com/uploa...1590591935.jpg

http://forums.pelicanparts.com/uploa...1590591935.jpg

Great thread! I was wondering what happened after you recovered this one! Wayne, your perseverance is amazing, and it seems like you're so damn close!

Can't wait to see what solves the problem, and with everything that's been changed I hope it runs like a top.

Cheers,

- Craig_D

Been several years since I laid hands on the 3.2 engine and have only skimmed a few pages.
Does your car have the WUR Warm up regulator?

Chiming in here, and hoping this is wrong and not a head slap moment, but everything I've read here concerns either fuel supply or electronics. I've had numerous occasions on my '84 3.2 911 where it would hunt for idle and would be bad enough that the engine would die completely between shifts, but seemed to run fine at constant speed. I found the solution on another forum and it was simply to insure a good seal on the oil fill cap. I've seen other threads as well where someone went out and bought a replacement cap but it still didn't seal well enough causing the problem to continue. If it is that simple, the rest of the work done to date will make that beast run like new, and for a long time.

Hi,
I just came across this thread due to the email 'Help Wayne Dempsey with his Latest DIY Puzzle' I received. Currently I am in the process of converting my 914 with the identic 3.2 motor. Previously it had a 3.0 from a 911 SC. So conversion is, apart from the electronics and electric connections, relatively straightforward. As I own a 911 3.2 as well I already came across some issues of this motor and maybe my hint can help you. I did not go through all the messages here so I am unaware if the Lambda sensor has already been excluded as cause of the problem. But to me it might be a problem that the sensor is at the exhaust and therefore it receives cold exhaust gasses. At the 911 the sensor is nearby the headers (downstream of the catalytic converter) and therefore receives hot gas. I intend to weld a nut on top of the (original replica 914-6) heat exchanger where the three tubes from cylinders #1, #2 and #3 come together. This point is the nearest where the sensor can be put and hopefully the gasses will still be hot enough.

Hopefully this helps a bit.

BTW excellent and interesting thread!

Wayne, i was wondering? Do you have to have that bend flange on the afm? You could use simple one like i have on my 911?
ivan

Wayne,

Have you checked the oil vent lines between the oil tank and the engine? The tank is part of the intake system on a 3.2, and if there is an air leak anywhere in the tank, it will cause all sorts of lean running mischief. Kinda like a 1.8L 914 with bad oil cap seals. Also, the oil vent line between the tank and the intake should have a restrictor in it to make the engine idle with the oil cap off. Lots of 914-6 3.2 conversions forget to put it in. Without it, there is too much air bypassing the AFM and that could cause lean running at idle.

Good luck.

Clay Perrine

herehttp://forums.pelicanparts.com/uploa...1590596990.jpg
many bmw places have this
ivan

I would bet money you have vacuum leaks at the insulators between the heads and the intake manifold. I also have seen some of the rubber boots on the intake halves joint leak. Reseal intake manifold, fuel injectors, upgrade to Griffiths hoses on all 3 fuel lines, and all vacuum lines and I bet it runs well. Just get it warm and misfiring and spray the bottom of each intake runner to find the worst offenders. You'll see the immediate improvement on the wide band or gas monitor.

Good Luck,
Chris

Simple Auto Solutions

Plug wires
 

I had a 3.2 and it ate up factory plug wires. Changed them twice in 25,000 miles.
The car had similar symptoms.. I don't know why but from new it always smelled like hot rubber after shutdown. Never could find out why. Most troublesome Porsche I ever owned worst of 5

I'm late to the party, and I haven't read through all your posts. I did try to read quite a few. It looked like you did swap many parts.

Did you get this resolved? I know you have had lots of suggestions, and this may sound kinda rookie, but did you swap in a known good DME? That is one component that I didn't see you swap.

I saw you did injectors, crank sensors, O2, AFM, and Temp sensors (which is what I thought it might be until you tested them). I wish your thread had a bit of a recap with things that were already tried.

In my time with 3.2 engines, I have found them to be reliable and fairly simple to troubleshoot, but as everything else, they are getting older.

You seem to have a wealth of knowledge in this thread, and I wish you the best of luck in getting this resolved.

Wow, after all this trouble shooting and so many fancy electronics I would have thrown in the towel and gone ITB's or a nice set of proper Webers !

Check your catalytic convertor or muffler for flow. I had a car with similar issues and the muffler had a baffle that when run for a few minutes would block the exhaust flow

I’m an SC guy so the 3.2 is a bit unfamiliar. But I wouldn’t say that ignition problems show up immediately. Specifically, I’ve had many issues with brand new coils once Bosch began manufacturing them in Mexico. As the coil warmed the issues surfaced. Had similar issues with braided plug wires. And the infamous decel valve on the SC - that one was fun to troubleshoot 🙄

Man, there's now an over abundance of "cooks in the kitchen" and many are suggesting
things that have already been tried. Suggestion, before posting ideas, go to page 15
of the thread Post 283 and you will find Wayne's synopsis of the many things he has tried. Kinda will get you somewhat up to speed.

yes, guys as said above... do some reading before comments.....
Ivan

Any more detail on the parts shown in this pic? Specifically the adapter that bolts to the AFM? Wayne's build has something similar.
Thanks,
Bill