1988 -80 cold start and idle problem
10-10-2000, 07:02 PM
#1
New Member
Thread Starter
Join Date: Oct 2000
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
1988 -80 cold start and idle problem
I wrote about this cold start problem a few days ago. The car starts only after repeated attempts when cold, starts immediately if warmed up. Checked plugs, they were dry and looked excellent. My guess was that the fuel pressure regulator was bad, but I don't want to pay $250 to find out either, or $85 an hour for a diagnosis by the local Audi dealer. NOW, the car starts with fewer tries, BUT, it revs on its own up to 2500 or so right after starting. I try to idle it down by pressing the pedal a little, but it just starts to stick at the higher RPM. After a few minutes of stop and go driving, the idle returns to normal at around 950. Is this still indicative of a bad fuel pressure regulator, or does this sound more like the cold start valve? I won't rule out the fuel pump buI personally I doubt it. PLEASE HELP!
10-10-2000, 09:29 PM
#2
New Member
Join Date: Sep 2000
Posts: 152
Likes: 0
Received 0 Likes
on
0 Posts
Re: Does it idle and run well when warm?
If so, we are talking temperature here.
Typical KE Jetronic system pressure is 5.5 bar (80psi). Have you checked this? If it's not to spec, you may need to replace the pressure regulator.
Have you checked your coolant temperature sensor, as was previously suggested to you, but you seem to ignore?
Typical KE Jetronic system pressure is 5.5 bar (80psi). Have you checked this? If it's not to spec, you may need to replace the pressure regulator.
Have you checked your coolant temperature sensor, as was previously suggested to you, but you seem to ignore?
10-10-2000, 11:14 PM
#3
AudiWorld Member
Join Date: Apr 2000
Posts: 177
Likes: 0
Received 0 Likes
on
0 Posts
don't think your FPR is bad,
of which this could either cause a rise or loss in residual pressure. Is more likely caused by a faulty ISV (idle stabiliser valve), vacuum leaks etc.
Look in the archives for the procedure to check ISV. Also check if your cold start valve is working (remove the valve from the intake manifold and start cranking when the engine is cold - if it spray fuel than it's fine, if not probably caused by a defective temp sensor).
Hope this will help you.
Look in the archives for the procedure to check ISV. Also check if your cold start valve is working (remove the valve from the intake manifold and start cranking when the engine is cold - if it spray fuel than it's fine, if not probably caused by a defective temp sensor).
Hope this will help you.
10-11-2000, 03:46 AM
#4
New Member
Thread Starter
Join Date: Oct 2000
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
Re: Does it idle and run well when warm?
yes, idles and runs excellent when warm, starts quickly, etc. have not checked fuel pressure for 5.5 bar or coolant temp sensor. Will try this, thanks very much
10-11-2000, 04:05 PM
#5
New Member
Join Date: Sep 2000
Posts: 11
Likes: 0
Received 0 Likes
on
0 Posts
Re: 1988 -80 cold start and idle problem
Have you done the output checks using a spare fuse in the top of the fuel pump relay? This will tell you if the cold start valve, ISV, etc. are working.
Thread
Thread Starter
Forum
Replies
Last Post
RodMc
Misc. Models Discussion
6
02-09-2003 06:49 AM