cosworth

Author
Discussion

nspasser

Original Poster:

88 posts

215 months

Friday 10th October 2003
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When starting up from cold it revs up to about 2500rpm and stays around that mark for a few seconds then dips to about 1700rpm. It sometimes dies down to about 300rpm then spurts into life up to 2500+rpm. Ive stripped and cleaned the idler and its improved to this condition. It was much worse at one time. Once warmed up it stabilises at 900rpm. Any ideas anyone? Its been chipped, remapped, bigger injectors actuator etc

>>> Edited by nspasser on Friday 10th October 20:38

deltaf

6,806 posts

221 months

Saturday 11th October 2003
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Possible air leak? Or perhaps a mapping/software fault?

If you want to look for air leaks, get a can of carb cleaner, and spray it around air pipe unions, intake gaskets etc, while the engine is running.
Use it sparingly.
Any induction leaks will show up as a rise/or stabilisation in engine speed.
If nothing happens, then you have no air leaks.

Hope this helps

mark-rs

44 posts

231 months

Monday 13th October 2003
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sounds like coolant temp sensor remove it,clean it up,especially the connector terminals...what spec is cossie and what plugs you running?

mark

>> Edited by mark-rs on Monday 13th October 07:02

andycanam

1,225 posts

232 months

Monday 13th October 2003
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Sounds like a sensor to me as well.... if its thinking the engine is warm when its actually cold it will struggle to idle.

However
I used to suffer very badly with this and it would take a while to clear... it was especially bad after heavy rain.
Eventually I found that the terminals on the idle control valve were all corroded as water had been getting into the plug... I cleaned them all up and managed to stop the water ingress and have never had a problem with idling since and thats 8yrs on.

nspasser

Original Poster:

88 posts

215 months

Monday 13th October 2003
quotequote all
mark-rs said:
sounds like coolant temp sensor remove it,clean it up,especially the connector terminals...what spec is cossie and what plugs you running?

mark

>> Edited by mark-rs on Monday 13th October 07:02




its a 1989 2 wheel drive, racing plugs, bout 330-350bhp. Sounds like that sensor, it'll be off when it comes back from the spray shop.

thanks guys.


>> Edited by nspasser on Monday 13th October 22:58

accident

582 posts

224 months

Sunday 19th October 2003
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check the blue plug at the back of the head on the inlet side.
also air leaks