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You have nothing to lose by trying the 2 above things and that way you know you have addressed potential water in fuel and poor gas.
Thanks for the input!
I checked at the tank through the inspection hole on the top for any water. In addition, I used fuel system cleaner to dislodge any water molecules which might be in the fuel lines. Unfortunately no change.
Also I am filling with 98 or 102 only. I am based in Switzerland - I believe the fuel stations for 98 are well used.
There are tiny little filters in each port of the FD. That's the thing you say floated to the top. Carefully remove all of those and clean them and the ports.
Thanks!
They did not really look dirty or clogged. Flushed them against direction of flow with brake cleaner regardless.
One outlet has now "taken in" the fluid. The rest are still at the same level.
After the slow method did not seem to do the trick, I went all in.
Took apart the FD to check what is going on. Really took my time and did not rush anything. Long story short: problem seems to be fixed. Car actually pulls now, really quick on the throttle input. I still have a very mild pinging on 1/4 throttle. Will have to get that dialed in, I guess the previous measurements do not hold true anymore. Since I only had 5.1 bar of fuel pressure previously, I added one shim (1mm) to increase system pressure. Resealed with Hylomar M, very thinly; paid attention not to get to close to the openings of injectors, WUR and plunger. Torqued to 5.5NM.
Did not find a blockage, but very small particles of dirt here and there. Polished the plunger casing with the towel - there was just a bit of dirt in there, but nothing compared to what I saw online in other cases.
Replace the O-rings with Nitril-rings I had laying around and fit the measurements.
Pictures are pre-cleaning (cleaning done with brake cleaner and microfiber towel):
Last edited by Dr.Digga; 09-24-2022 at 03:14 PM.
Reason: Torque Values
Just a quick update - car still stutters when it is really heat soaked.
I now have bought a A/F Meter. The car is actually running rich when fully hot. I had it dialed in at 14.7 when hot, but garage hot. After around 20-30 minutes drive, the mixture is starting to richen up to a A/F ratio of 8.4.
I have though about the AAV, but it is fully closed when hot. In addition the AAV uses metered air, right? Maybe a leaky start injector? I assume the WUR can only go lean, not rich when starting to warm up? Not quite sure where to go from here... Every time I seem to "fix" something, the problem simply appears somewhere else.
Just a quick update - car still stutters when it is really heat soaked.
I now have bought a A/F Meter. The car is actually running rich when fully hot. I had it dialed in at 14.7 when hot, but garage hot. After around 20-30 minutes drive, the mixture is starting to richen up to a A/F ratio of 8.4.
I have though about the AAV, but it is fully closed when hot. In addition the AAV uses metered air, right? Maybe a leaky start injector? I assume the WUR can only go lean, not rich when starting to warm up? Not quite sure where to go from here... Every time I seem to "fix" something, the problem simply appears somewhere else.
The leaky cold start injector is a possibility. It only fires when cranking and only when the coolant temp sensor closes to complete the ground back to it, so I can't see how the failure mode you have where it gets rich after it's hot can be related to the electrical side of the cold start injector....BUT, it could be related to the mechanical side of it if fuel pressure is building up at it and it's spraying into the manifold even when it's not electrically being told to do so. You might be able to remove it, tape off the opening where it installs, insert it into a jar and run the car. When it gets hot, if the injector starts dripping or spraying fuel, that might be it.
With your AAV being fully closed when the symptoms start, that's eliminated as a possible issue, leaving the WUR as the other possibility. It's supposed to adjust fuel pressure based on temperature. If it's not working correctly in sensing the temp and adjusting, it could certainly cause the mixture to get incorrect, and since you seem to have determined it's a temperature dependent failure, I think this and a mechanically leaking cold start injector is where I'd focus.
The problem has gradually gotten worse. Now the car does not even want to start.
The following was done since last October:
- Crud in fuel tank: positive, cleaned tank (fuel flow initially too low, now around 1 litre/min)
- FD rebuilt
- WUR rebuilt (correct pressures tested with CIS testing kit)
- new distributor cap
- new ignition wiring
- new green wire
- new injectors
Car still does not want to start. Spark is good, compression is good, control pressures at WUR also good.
Fuel pressure accumulator is leaky. However, I would not think that this could result in a no start condition? Any further ideas?
True! I forgot to add that.
I checked timing on the cams as well as the ignition distributor. Seems to be ok also.
What do you mean in regards to cps and speed sensor?
Edit: I guess you mean the crank position sensor. I think the `80 CIS cars do not have one?
True! I forgot to add that.
I checked timing on the cams as well as the ignition distributor. Seems to be ok also.
What do you mean in regards to cps and speed sensor?
Edit: I guess you mean the crank position sensor. I think the `80 CIS cars do not have one?
mmm yes i am not sure whats on the earliest cars, whilst i did have an 81 for a few months, i never got deep into fixing so most of my experience is 85 and later (plus a bit of 944 confusion on top) Search your manaul or PET or someone with MY specific knowledge can assist. I was just thinkjng basica if fuel spark and compression are there. May not explain any previous link to temperature though
A new fuel pressure accumulator did not do the trick. Still running really rough, if at all.
Another idea would be the ignition Computer. Would you have any wisdom if thst would explain some of the symptoms?
So, a bit of an update: Fuel side
- New injectors, filter (in tank and fuel pump), pressure accumulator, lines, rebuild WUR and FD
- fuel pressures incl. control pressure in specs
- fuel delivery rate ok
- equal fuel delivery per injector
Ignition
- new ignition cables, distributor cap, ignition coil, spark plugs, new green wire
- checked timing (timing marks line up at crank, TDC and inside rotor (with mark)
- checked correct ignition wiring
Compression is ok at around 145psi per cylinder (cold)
Car still does not start. After multiple start tries, it backfires into the exhaust as well as on the intake side.
My mechanic thinks it is the distributor rotor. Would you have any further ideas?
fuel accumulator needs sorting if it is leaking, did you rebuild the fuel distributor properly as it requires a lot of precise measuring and setting up on rebuilding
To keep you guys updated.
It seems fuel has gotten into the oil to such an extend that it actually increased the volume so much that the engine was sucking oil via the oil breather.
When checking the dip stick one could clearly see the oil mark, but the fuel was way higher, but barely visible. So we did not realize earlier.
After dropping enough oil, car runs for a short while now until the plugs become fouled and require cleaning again.
We will completely change the oil and give it a good run.
However, we are still unsure how the fuel has gotten into the oil. Compression is good on all cylinders.
Very relieved that we seem to have found the cause here...
09-24-2022, 07:06 AM
