480 turbo idle

Jun 2nd, 2004, 19:14

I have a 93, 480 turbo which on cold start has a very lumpy idle around 500 r.p.m ,as the engine warms up the idle increases,
at 60 degrees it idles smoothly about 850 r.p.m. by the time the engine temp. is in the 90's, the idle has increased to around 1200 r.p.m. Performance throughout the range is OK, starting when warm OK.
any ideas ?

Steve Hogg · Jun 3rd, 2004, 19:43

Hi,

I think the most likely culprit is the coolant temperature sensor. If you check its resistance it should be in the range 2200 - 2800 ohms at 20°C. If thats ok next check the air temperature sensor which should have a similar resistance. Finally check the idle speed regulating valve, on turbo models this should be about 20 ohms.

Good luck.

Steve Hogg

480 ES
480 Turbo
460 SE
760 GLE Estate
760 GLE Saloon
A few non Volvo's

Jun 3rd, 2004, 21:28

thanks steve i'll check those out

Jun 2nd, 2004, 19:14	#1
alexfairbridge Guest Location:	480 turbo idle I have a 93, 480 turbo which on cold start has a very lumpy idle around 500 r.p.m ,as the engine warms up the idle increases, at 60 degrees it idles smoothly about 850 r.p.m. by the time the engine temp. is in the 90's, the idle has increased to around 1200 r.p.m. Performance throughout the range is OK, starting when warm OK. any ideas ?

Jun 3rd, 2004, 19:43	#2
Steve Hogg Member Last Online: Jul 8th, 2018 10:38 Join Date: Dec 2002 Location: Taillebourg	RE: 480 turbo idle Hi, I think the most likely culprit is the coolant temperature sensor. If you check its resistance it should be in the range 2200 - 2800 ohms at 20°C. If thats ok next check the air temperature sensor which should have a similar resistance. Finally check the idle speed regulating valve, on turbo models this should be about 20 ohms. Good luck. Steve Hogg 480 ES 480 Turbo 460 SE 760 GLE Estate 760 GLE Saloon A few non Volvo's

Jun 3rd, 2004, 21:28	#3
alexfairbridge Guest Location:	RE: 480 turbo idle thanks steve i'll check those out

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