i have a 89 toy pickup that runs at a high idle it starts to warm up and whan you push on the brake it starts to miss and the idle comes down low. i checked for vaccum leaks and found none. i then went and pushed on the pedel and held in the brake light switch and the idle would not change. as soon as i let go of the brake light switch it would miss and idle would come down. can you help??
89 toy pickup
Mar 07, 2006
2 Replies
As a safety measure, with the brake applied, the computer is shutting down the high idle. When the idle speed lowers to a specific RPM the computer "thinks" all is well, until the idle runs up again and the computer again shuts down the high idle. Thus the surging. You may have to adjust the Throttle Position Sensor (TPS). Here's a link:
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hey thank you very much i will try that and let you know what i find. thanks
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