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Morning all.

I followed Bill J's procedure on cleaning the Idle Control Valve. The car ( 96 lpt cse ) idles fine most of the time but when the ACC is turned on ( set to 'Auto' mode ) the rev counter jumps up and down between 1000 and 1500 rpm. I presume the engine is now over-compensating for the load caused by the ACC. It idles fine when the ACC is set to the 'econ' setting.
Any ideas
 

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My '97 2.3 LPT manual does the same thing occasionally when the ACC is set to AUTO. I have not yet cleaned the Idle Control Valve but I was going to try this next. I was also wondering about cleaning the Air Mass Meter, not sure if this might help?

Either way, if anyone has had this problem please speak up...
 

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Just re-read your original posting about your problem, sounds like it could be a faulty air-con pump clutch cutting in and out. Either that or you have the temp. on the ACC set close to ambient air temp. and the air-con is cutting in and out very quickly to maintain the temp. you've set. This would make the engine idle speed go up and down alarmingly!!
 

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Stephen,
Thanks for your thoughts.

How right you are about my 2.3 Trionic not having an Air Mass Meter, I found this out this evening when I went to clean it

Does anyone know what inlet manifold vacuum I should expect at idle speed? I am reading only 17-18 Ins Hg and the reading is fluctuating slightly so I wonder if this might help solve the idle problem

Thanks,
James
 

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When I cleaned the valve on my CSE auto, I had similar symptoms. I guessed it was because the valve had been so gummed up the ECU had been having to drive it hard to open and close it and that perhaps operation of the valve was adaptive. I disconnected the battery for a few minutes to reset the ECU and it worked smoothly after that.

That was a '96 LPT too.
 
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