Been having start, idle, continue to run problems with my "78, 928 5 speed.As the engine stops I hear a sound coming from the top of the engine that sounds like the proverbial rusty hinge on a gate. I am going to take off the air cleaner assembly and try to dtermine if the sound and my problem is coming from a sticky sensor plate, control plunger or throttle valve. Just wondering if anyone has encountered this sound/ problem in the past ?

 

I know something similar was discussed years ago, but my addled brain can't recall the specifics. Do a good dig into the archives or the email list archives (more likely). Or DW or JP may come to the rescue...

 

Thanks, will do.

 

Do you get a prompt restart, or have to crank a bit? Maybe it is the pressure bleeding down out of the FD if the check valve is shot.

 

Car will not start without long cranking and depression of accelerator, then stalls.

 

I also hear the sound when turning the crank by hand to check timing belt position.

 

That's weird

How would cranking the engine by hand be related?

Did the problems just start?

Let us know if the air valve plate is sticking.

 

Just noticed sound friday and yesterday. Car will sometimes start and idle roughly and then shut down. As it shuts down I hear the sound. I am going to take a closer look later today and will report any findings.

 

Since the only moving parts on a CIS injection system is the air sensor plate and control piston, it is doubtful these would be making this noise, especially when hand cranking. I would look at the air pump, alternator, and power steering pump initially, then go to the timing belt system to check for bad idlers or water pump.

Concerning the starting issue, it sounds like the auxilliary air valve isn't opening when cold.

Dennis

 

air pump bearings giving out. there you go Dennis!

 

Thanks for your response. No air pump on car--taken off years ago. Aux air valve open. When I press down on air sensor plate it seems to take a lot of effort to get it to move down and somwetimes as it goes down it makes a hissing sound similar to what I heard before. Also, with someone trying to start the car the plate moves only a little and sometimes not at all. I think I am going to have to take the air sensor and fuel distributor off and inspect and clean and also take a look at the operation of the throttle valve. Car will not start now but will rev very high sometimes if I press gas pedal to the floor while attempting to start but then won't idle or continue to run. Recently did fuel pressure tests --all pressures good.

 

The air sensor plate should have some resistance due to the control pressure, but the movement should be smooth. Try taking the distributor off and checking the control piston for free movement and check the air sensor plate movement. The hissing sound when you move the plate down is from residual system pressure going through the distributor to the injectors.

Has the car sat for a long time or did these symptoms just start?

Dennis

 

Car has not sat for a long time. I have been having driveability problems. Car was running fine one evening but then started to stumble at highway speeds. Then would stall at idle and cough and stumble as I pressed on gas to keep her going and then stall again as I would slow down to stop at corner, etc. Now will not start and idle. Pain in the neck mystery. I will have to check everything out as you suggest. Hope I can pinpoint problem --don't like replacing expensive parts like fuel distributor only to have same problem.

 

How old is your fuel filter? While you are checking things, look at the fuel pump fuse and relay contacts to make sure they aren't causing a voltage drop at the pump.


Dennis

 

Fuel filter replaced yesterday previous one had about 25,000 miles on it, also put techron in 1/2 tank of gas. Recently replaced fuel pump circuit wire and fuse at relay/fuse panel. Last week replaced engine wiring harness with one from Carl Faucett--everything connected properly. Fuel pumps are operating when I attempt to start car. May be I will check voltage at fuel pump when cranking to make sure OK.