Not good.

[hoover]

Looks like the future is bleak for my car, recently it started to hesitate while driving, maybe electrical maybe fuel issues. However things got worse, now it won’t tick over, is spluttering and missing with blue smoke out the exhaust. It needs high revs to keep running, even then tries to cut out. The end pipe is black and shows a rich mixture.
No way can this car be driven, I was lucky to get home the other day. I’m wondering about the head gasket. I’d like to know what’s gone before making a final decision about the car. It doesn’t sound something simple. Not easy without looking but any thoughts?

[thomasryan]

pull the plugs and see what's up

[ERAU944]

If you find your injectors need cleaning send them my way!

[hoover]

Thanks for quick reply, it’s laid up at the moment but with the advice I’m getting, I’ll be investigating these thoughts. I’m suspecting I’ll see water from the cylinders but I do hope not. Hope to check it out when I get clear of a few things.

[curtisr]

As an alternative you can purchase an inexpensive setup and blast away. For an added bonus the manufacture reports that it's 'trendy'.

[Jfrahm]

The future is certainly bleak for a a car driven when spewing fuel from a blown FPR diaphragm, or something like that. Hopefully not driven too far. The oil is probably contaminated with fuel and should be changed after addressing the root cause.

Not sure why you'd think head gasket without white smoke, it'd be easy enough to look at the spark plugs and get a lot of info.

[hoover]

Just an update on this issue, I pulled the plugs today, they were black with soot. I also did a compression test and got what I thought was a good reading on all 4 cylinders. (210 lbs square inch) or (15kg per square cm) I’m thinking of cleaning the control valve again, the one under the manifold. I cleaned it recently but maybe not good enough. I don’t know why the mixture is suddenly so rich.

[MKEDF]

I just had an issue with my 1983 944, the car did not start, but the issue was the fuel pump, then as replaced, started but died after a minute or two of running (i could have several spins on it), but after it died, a strong smell of gas all over, had to wait for an hour to start it again, and died again, i found out that the obd temperature sensor could be the cause, so i checked, and the plug was loose.

So i attached it again and it works properly, also i had to replace right after the fuel pump one of the pressure dampers, and now the car starts perfect and runs smooth!!...take a look at the temp sensor, right under the engine admission!!

[Jfrahm]

Usually because of a blown FPR or a bad DME temp sensor, or a hosing injector.
Careful running it, the cat (if you have one) might get very very hot and melt stuff. Better to diagnose the issues with as little running as possible. A DME relay jumper can be used if you need to run the fuel pump to see if it holds fuel pressure, watch fuel jet out of the FPR vacuum port, etc.

[hoover]

Ok thanks for the additional thoughts, I’m making a list of tests and checks to make.

[mytrplseven]

Don't give up on her. She's a beautiful lady and deserves your help.

[hoover]

Thanks for the encouragement, it will be hard to let go. I‘ve had the car 20years but sometimes there comes a time. Maybe not just yet though. Removing the distributor cap tomorrow, maybe some oil contamination.

[walfreyydo]

Oxygen sensor, fuel dampener, fuel pressure regulator, vacuum leak (check hoses), possible AFM stuck open. If only one plug looks sooty (and not all of them) you may have a injector stuck open. You are smelling strong fuel smell, black soot on plugs, something is causing it to over fuel...

[hoover]

Thanks for your thoughts, they will go on my list to check. I’m not getting very far with this issue to date. The distributor cap was clean, although the carbon centre pin was not protruding a lot, and a little pitted, however I stretched the internal spring but it made no difference.
All the plugs are very sooty. I have bought a new fuel filter prior to getting the injectors cleaned but not convinced that’s the problem. Nice to get your reply.

[thomasryan]

fuel pressure?

[OK-944]

Hey...thats quite a bit of compression you've got there! (should be closer to 165 per cylinder, not 210) Could be a bit of excessive carbon buildup on piston tops and/or combustion chamber and valve faces, which could in turn be interfering with air intake...so that you'd really need to floor it to keep it running, but the mixture would indeed be rich for the lack of air.

Question: has this been a "cool running" car for awhile? Running too cool can cause carbon buildup and lead to these issues. If this is the case...this could indicate something with the cooling system, like a stuck-open thermostat or wonky thermo-switch.

[hoover]

Hi, sorry not responding earlier, Only saw your post by looking back over the thread ! I didn’t get my usual automatic notification of a post.
My car has always run at the same temperature; just a little past the first graduation on the gauge, so I wouldn’t say particularly cool running.

[kdjones2000]

This car is an S2, not your normal 944 NA...

This uses an ICV, not an ISV. It has the next generation Motronic electronics.

Be careful what you recommend.

[TibetanT]

Hello there:

I am no expert, but...check your Hall Sensor.
If this car is like mine, 1987 944S there is a sensor next to the Power Steering reservoir on the block. Just below the valve cover and to the back of the cam cover.

The Hall Sensor is responsible for timing and if it goes bad...well, all types of issues can happen such as you describe.

The ECU/DME is responsible for getting a signal from this "sensor" and then relaying that information to the DME relay within the fuse box for fuel getting to the injectors.

Blue smoke is a "too much fuel" problem. And, it sounds like you are getting too much fuel since your spark plugs are black.

?? When you pulled the spark plugs, were all of them black and is the black like tar?
Or, is the black more like soot?

Black like tar usually means oil is getting past the piston rings, or valve guides are bad. However, your compression is really good.

This car you are speaking of is a 3.0L correct? 944S2 ?

Hope this helps.

[hoover]

Thanks for that. The plugs a sooty black appearance. I’m juggling this issue in between other things as it’s come at an awkward time. Sorting it all out is taking time. Anyhow grateful for your responses. (3 litre S2)