Idle speed

Idle speed

Author
Discussion

Dave350iTVR

Original Poster:

126 posts

278 months

Sunday 17th February 2002
quotequote all
My car has recently started to play up when left to idle. What is the recommended idle speed? I thought around 800 to 1000 RMP but it tends to fall to 600 and sound pretty bad. I tried to alter this with the idle screw but all efforts seem to have failed to maintain a constant idle speed. Any other suggestions?

Steve Heath suggest's the correct setting to be screw down until it stops and then unscew the grub screw for two and a half turns. If this method is used the engine starts and then just cuts out straight away. It needs to be a lot higher....but how high I don't know!

>>> Edited by Dave350iTVR on Sunday 17th February 21:38

c j morgan

44 posts

277 months

Sunday 17th February 2002
quotequote all
my 400se ticks over about 900 rpms i dont know if its
the same for the 350

Dave350iTVR

Original Poster:

126 posts

278 months

Sunday 17th February 2002
quotequote all
It sounds good at 900rpm the problem is keeping it there. Not sure if my grub screw is now too far out allowing too much air intake. Anyone done this recently?

GreenV8S

30,627 posts

294 months

Monday 18th February 2002
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quote:

It sounds good at 900rpm the problem is keeping it there. Not sure if my grub screw is now too far out allowing too much air intake. Anyone done this recently?



Do you have a similar idle control stepper motor to the later cars? If so it may be this has stopped working. Could also be a more conventional ignition or fueling problem. Worth checking the spark timing (strobe) and strength (spark trace) and mixture (colortune) to see if either shows a problem.

Cheers,
Peter Humphries (and a green V8S)

Dave350iTVR

Original Poster:

126 posts

278 months

Monday 18th February 2002
quotequote all
After playing with the idle gub screw I seem to have got it just about right but not sure about how to control the mixture level at the moment. Besides I'm still a bit gutted about the whole clutch release bearing problem. Dohh!

350matt

3,799 posts

289 months

Tuesday 19th February 2002
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I'd check the rest of the inlet system for leaks as it sounds like you're pulling in air after the metering unit. A very effective way to find air leaks is with the engine running to spray lighetr gas around all the joints and if the engine rev's up you've found your leak. Remember to check all the push on hoses around the plenum.

Matt