Need help, high idle speed?

Question

I have a 1992 ford ranger that has a high idle which is causing the truck to jerk into drive and reverse. (3.0 V6 engine)

I cant get the idle down, it is running at 1050 rpm.

I have replaced the TPS, idle control valve, and pcv valve.

There is no vacuum leaks.

Is there any other sensor that can cause this?

Answer 1

HArd to describe, BUT there should be a "s***w" at/on top of the intake manifold... this can be tightened SLIGHTLY to drop the RPMS and or loosened to "up" the RPMS... perhaps you can drop by a Mechanics shop to free peace of mind... maybe have them point it out to you... this should not cost you anything...

best wishes...

Answer 2

Could be a MAP airflow sensor. The only way to know for sure would be to take it to a garage that has the equipment to diagnose your problem. Expensive, but better than replacing sensors or parts in the hope that you may stumble upon the problem.

Answer 3

A bad battery can cause the engine to speed up,improperly installed IAC can cause it,A vacuum leak in the vacuum advance can cause it,Because it throws the timing off,linkage to the stepper solenoid on the carburetor may not be properly set.

Answer 4

Try resetting your computer.  disconnect the battery for an hour or so then reconnect it and hopefully that'll do.  If not take it to a tuning shop and it should be a reletively easy quick fix

Answer 5

The mass airflow sensor (MAS)could be causing a high idle but its doing it for a reason if thats the case. The MAP(Manifold absolute Pressure) sensor will not cause a high idle. It would help to know if your Rangers MIL(malfunction indicator lamp) is lit or not. If you have a steady service engine soon light burning, have the codes read and cleared. Advance Auto  Parts offered that service for free back in early 07 as I recall.Once the codes are cleared I would re-boot the trucks computer. Do this by disconnecting both battery cables from the battery and leaving it disconnected for a couple hours. After that, re-connect everything and start the truck, if it still idles high, I would suspect some kind of physical or mechanical obstruction holding the throttle linkage partially taunt. Drive the truck and your MIL should come back on. Have the codes read again and this should indicate approximately where the trouble is. It will at least give you a good idea as to where to start. .  

Answer 6

I don`t think there`s another sensor that could cause this, but it could be that your throttle linkage is sticking, or your idle speed is not properly adjusted. On the V6, incorrect valve clearances will cause this also.