Need some input -> Problem with 3.2 transplant going lean and misfiring after two min

[Steve W]

The way your injectors look, it's as if the insides of your intake manifold are full of crud, and/or some type of material or sealant used on those intake boots is disintegrating. Maybe time to pull off the intake manifolds, check and clean everything up, maybe even get the TB rebored.


Sure the insides of your gas tank doesn't have any rust in it? Did water ever get in the fuel system (i.e. sitting outside without the gas cap on in the rain)?


Also how much and what type of fuel hose is in your system, and how old are they? Are they ethanol rated?

[ischmitz]

So something downstream from the fuel filter acts as contamination source and plugs the injectors. That’s in agreement with the yellow stuff you called fuel the other day.

I’m not too familiar with the 3.2 but assume it also has a fuel feed line and a fuel return line to the tank. Does the 914 have the same layout?

I’m still concerned that a car sitting for years might have created a form of reservoir of broken down fuel inside the fuel system downstream from the fuel filter. That might be what’s going through the injectors.

The black stuff that’s on the tips of the injectors is from where they’re exposed to the air from the intake runners. How is the oil breathing system realized and is it possible the stuff on the injectors tips comes from there. I don’t think it’ll plug their internals though.

[Solamar]

After reviving my car from a 15 year slumber, I ran a new fuel filter for 1000 miles then cut it open like an oil filter to visually check for debris.

Might be worth cutting your filter open.

[scarceller]

Flush each injector port at the rail, Lift the rail and remove one injector, put a length of hose on that injector port into as catch can. Run the pump to flush.

Repeat for all injector ports till fuel is clear.

But you will likely have contaminated filter screens in the injectors, they will need to be cleaned again.

[scarceller]

How long has the fuel been in the tank? If it's E10 the ethanol may have separated and you now have it sitting at the bottom of the tank? Why not just run the pump and use the hose to fully empty the tank, then fill with 5gal fresh 91 or 93 octane fuel.

[Wayne 962]

Originally Posted by scarceller

How long has the fuel been in the tank? If it's E10 the ethanol may have separated and you now have it sitting at the bottom of the tank? Why not just run the pump and use the hose to fully empty the tank, then fill with 5gal fresh 91 or 93 octane fuel.

Did that - twice (well, now three times). There might be some hidden spot in the tank that is causing sloshing when the fuel level is low or something like that. I'm done mucking around with this - I will pull the fuel tank and replace it if it looks terrible in there. I probably should have done that originally, but all the fuel "flushes" I did looked very good, so I didn't think there were any issues.

-Wayne

[scarceller]

I do not know the 914 tank setup but the 911 has a screen at the bottom that gets really clogged with crud and such. I agree that if the tank looks bad it should be replaced/fixed.

What I have learned from other 3.2L that sat a long time is that they ussually have multiple things wrong and that really complicates things. The reason I often see multiple problems is that some time in the past the Engine develops and issue and someone band-aids a solution. For example, we are running lean so someone fixes this by loosing the spring tension in the AFM or they decide to crush the FPR in a vise to increase fuel pressure, I've seen both examples done! Then things get worse and the car no longer runs. Now we start figuring things out and you need to undo all the previous band-aids. I mention this because you may fix the fuel system and still have some other issue. You already found evidence of the spring tension possibly altered in the AFM, you need to keep notes on all the findings that seem like someone messed with something.

But dirty fuel like in your photos needs to be fixed first.

Originally Posted by Wayne 962

Did that - twice (well, now three times). There might be some hidden spot in the tank that is causing sloshing when the fuel level is low or something like that. I'm done mucking around with this - I will pull the fuel tank and replace it if it looks terrible in there. I probably should have done that originally, but all the fuel "flushes" I did looked very good, so I didn't think there were any issues.

-Wayne

[tonysc]

Hello from Spain, I use a google translator, sorry for the mistakes.
I want to give some restraints.
1º Check if the alternator charge is correct and check if it allows a lot of current to pass through the battery.
2º That so white color in the number 3 plug is proof of a poor mixture, with excess air, that's why in cold when the injection time is higher it hides the failure. Check for possible air intake.
Thank y

[Wayne 962]

Originally Posted by scarceller

What I have learned from other 3.2L that sat a long time is that they ussually have multiple things wrong and that really complicates things.

YES! About a week or two ago, I came to the conclusion that there were multiple issues with the whole setup. So far, we have:

- Goofy 180-degree bend on the MAF mount
- WOT throttle switch not working due to recessed connectors in the harness
- Ignition wires that look like they've been melted
- Cylinder head temp sensor out of spec
- MAF sensor that is worn and has been obviously messed with
- Intake boot leak (small one)

In addition, the other following issues due to age:

- Possible fuel system contamination
- Possible sealant breakdown or something in the intake manifold

I guess this type of crap is what kept Pelican in business for the 20+ years I owned it, so I can't really complain *too* much, right?

-Wayne

[Wayne 962]

Originally Posted by tonysc

Hello from Spain, I use a google translator, sorry for the mistakes.
I want to give some restraints.
1º Check if the alternator charge is correct and check if it allows a lot of current to pass through the battery.
2º That so white color in the number 3 plug is proof of a poor mixture, with excess air, that's why in cold when the injection time is higher it hides the failure. Check for possible air intake.
Thank y

Thanks - good observations. We did a smoke test (4 times), and that came back okay. The alternator charge is a good one, I believe that I tested / checked that already, but I can't absolutely recall off the top of my head. It's on the list to do though.

With the clog found in the injectors, I think that is a big clue though for the moment...

-Wayne

[john walker's workshop]

Did you happen to see any smoke coming out the fan, however minute? The lower intake gaskets, when they suck in or blow out would show smoke under the shroud, being the lower gasket is way down against the head. That's why you can spray stuff around the runners till the cows come home and it won't show an issue.

[Wayne 962]

Originally Posted by john walker's workshop

Did you happen to see any smoke coming out the fan, however minute? The lower intake gaskets, when they suck in or blow out would show smoke under the shroud, being the lower gasket is way down against the head. That's why you can spray stuff around the runners till the cows come home and it won't show an issue.

I did not see anything coming out of there, but I'm going to pull the manifold anyways now to check to see what's inside causing all of that black mess and stuff...

Knowing my luck, I'll probably create a vacuum leak by disturbing it!

-Wayne

[ischmitz]

Might as well put new gaskets in there if you take the intake off.

[john walker's workshop]

It can come out in two pieces, so you should be able to deal with it in situ.

[Steve W]

Since you're going to pull the manifolds, now is the time to replace those 35+ y.o. fuel lines, especially that big T line that can't be replaced without removing the right manifold. These are the ones that go bad and seep fuel, leave your garage smelling like gas, and bad enough there have been instances of the car going up in flames. The hoses harden also degrade from ethanol and you can tell how leaky they are by how easily the fittings spin around the crimps - they shouldn't. There are several options here, from OEM, to Griffiths or Len Cummings, to custom PTFE. My preference is the latter, as PTFE lines are the best and forever like polyamide tubing and will never degrade with exposure to ethanol and most any chemical, unlike rubber lines which will degrade and need to be replaced after 15 years. I had all mine rebuilt by Mesa Hose in Costa Mesa.

Speaking of which, on rubber hoses, you want at minimum fuel injection hoses rated SAE J30R9 or something like Gates Barricade J30R14. These are rubber hoses rated to withstand ethanol in fuel longer than standard hose. If this isn't the type of hose in your fuel system, the ethanol can degrade and dissolve the inner layer of rubber into your fuel system, clogging filters, injectors etc. If there's any rubber hose submersed such as inside your fuel tank (i.e. prepump), make sure it's submersible rated, or you'll get the same problem with the outer layer of the rubber hose degrading and dissolving into the fuel. If you take paint thinner and rub the outside of nonsubmersible standard fuel injection hose, you'll see the black rubber dissolve right before your eyes. Fuel hoses are typically layered with as much as 5 layers of different plastics and rubbers, each having a specific property and function. I don't know anything about the 914 fuel system and the lines from the tank to the engine and back, but pay attention to anything that is not polyamide.

[Wayne 962]

Originally Posted by ischmitz

The black stuff that’s on the tips of the injectors is from where they’re exposed to the air from the intake runners. How is the oil breathing system realized and is it possible the stuff on the injectors tips comes from there. I don’t think it’ll plug their internals though.

The breather system on this car is plugged and is independent of the manifold right now, so it can't be from that. I'll crack it open and see if I can tell where it's coming from...

-Wayne

[Wayne 962]

Originally Posted by john walker's workshop

It can come out in two pieces, so you should be able to deal with it in situ.

Actually, with the engine lid off and the rear trunk off as well, there appears to be ample room to just remove everything as one piece. Not 100% sure yet though...

-Wayne

[Wayne 962]

Originally Posted by Steve W

Since you're going to pull the manifolds, now is the time to replace those 35+ y.o. fuel lines, especially that big T line that can't be replaced without removing the right manifold. These are the ones that go bad and seep fuel, leave your garage smelling like gas, and bad enough there have been instances of the car going up in flames. The hoses harden also degrade from ethanol and you can tell how leaky they are by how easily the fittings spin around the crimps - they shouldn't. There are several options here, from OEM, to Griffiths or Len Cummings, to custom PTFE. My preference is the latter, as PTFE lines are the best and forever like polyamide tubing and will never degrade with exposure to ethanol and most any chemical, unlike rubber lines which will degrade and need to be replaced after 15 years. I had all mine rebuilt by Mesa Hose in Costa Mesa.

Yup, super smart advice there, and I've already spec'ed out the lines that need to be replaced. One of them was / is $183, and six inches long! That seems to be a bit ridiculous, even by Porsche standards (this was the line from the pressure regulator to the supply line). We've used Mesa Hose before for a lot of the hoses and connectors that we've replaced and/or created on the 962s - their stuff is top-notch even if they seem like they're stuck in the 1980s (carbon-paper receipts and stuff). The updated hoses are a good idea, indeed...

I emptied the tank today, saw some stuff in there, but didn't get a good, close look, as it's not completely empty. I will remove the tank tomorrow and take a closer look. The injectors and fuel rails go to RC Injection for cleaning tomorrow as well...

-Wayne

[cabmandone]

Isn't there a guy here that makes the lines? I was thinking a member did that.
Also there's this https://members.rennlist.com/imcarthur/fuel-lines.htm

Edit: Found it! Len at autosportengineering.com (boxsterGT here on PP) Here's a thread with his work go to post 10
88 Carrera Fuel line

^^ that thread has a couple of nice options. Len's solution and one called the Feeler kit link below
https://forums.pelicanparts.com/porsche-911-used-parts-sale-wanted/1011141-feeler-fuel-lines-3-2l-stainless-teflon.html


A thought on the fuel, if you're worried about contamination from the tank, couldn't you place an inline filter at the tank temporarily along with the one back in the engine bay? I'd think that double filtration would rule out contamination from the tank. I'd think that draining and filling several times like you have would dilute whatever contaminant might be in the tank. I'm assuming the 914 has the bung in the bottom of the tank that everything tapers to like the 911 does so I'd think unless it's a gelled mass that is in the tank, you'd have it cleared by now.

If I was questioning the fuel I think I'd try to plumb the suction side of the pump into a clean can of fuel for testing purposes. I haven't looked at how the lines plumb into the tank from the pump but I would think in a pinch for troubleshooting that it could be done. Something guys do on diesel engines is plumb the return to the tank into a clear glass and run the pump. This shows what's flowing through the system. I'd think you could do the same on this car since it has a return line.. right?

[tonysc]

Gracias, buenas observaciones. Hicimos una prueba de humo (4 veces), y eso volvió bien. La carga del alternador es buena, creo que ya lo probé / verifiqué, pero no puedo recordarlo por completo. Sin embargo, está en la lista.

Con la obstrucción encontrada en los inyectores, creo que es una gran pista por el momento ...

-Wayne

Delighted to be able to collaborate in this interesting thread.
Alternator current, I mean to check with meter the alternating current input to the battery
Cheers