how do i turn the idle down?

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migration_judge_roy answered 4 years ago

well there is may be a carburetor and you could adjust it just as you would a normal quadra-jet but is old technology and probably has a throttle body injection system...but the point is your ECM is going to set the idle speed, and you need to look for a vacuum hose that has fallen off...the fuel pressure regulator is an important one, because if it defaults...there will be only a vacuum leak (high-idle) and a lack of regulation from your fuel pressure regulator....think you should consider the notion of your fuel pressure regulator defective....things just do not turn up the idle by themselves~....unless there is a torn diaphragm on the fuel pressure regulator~

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Tracy answered 4 years ago

Ok - I work on a Fleet of Police Interceptors - 800 of them fully equipped and ready for battle. No. You cannot change the targeted Idle RPM. The PCM will do all it can to achieve the set parameter. If the engine is racing or just idling high, look for a vacuum leak. Remove and inspect the PCV system hoses and valve (both sides of it), Look for any unmetered air from the MAF sensor to the Throttle Body. Is the "Check Engine" light on? Since your Throttle is a "Fly-By-Wire" system (completely computer controlled = no cables), the computer determines everything the throttle does - it even backs off of the butterflies to soften the transmission shifting. Last vacuum advice (If there's no check Engine light) is to check over your plastic intake manifold and Brake Booster. These are uncommon failures though. Last but not least, I would hook up a scan tool and watch the readings of the MAF sensor, Long and Short Term Fuel Trims and upstream O2 sensor activity. Your fuel pressure regulator incorporates a fuel temperature and pressure sensor and the pressure is more regulated by the duty cycle of the pump than by an external regulator. You can read fuel pressure and Fuel pump duty cycle from the scan tool too.

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migunner answered 2 years ago

I am about to trouble shoot way too high idle on cold start, iac or vac, first gotta pull the data stream,