Questions and Answers

Toyota 4Runner SR5 High Idle Problems Q. I have a 1993 Toyota 4Runner SR5 with manual transmission. About 173,000 miles, fuel injection, ABS brakes, P/S, A/C and cruise control. Problem. While driving and shifting, at times when I am at neutral, the RPM goes up by itself without me stepping on the gas. It would then go down again when I put on foot on the accelerator, sometimes it will not go down.

Normally when not moving or at idle my RPM is at 1,000 but lately it's been going up to 1,500 without me stepping on the gas. It sounds like the engine is revving itself. Is this a timing belt issue? I just had it replaced less than a year ago. I recently notice this problem about a week ago after towing a boat, about 3,000 lbs. Please advise.

Thanks...

A. First we need to see if there are any codes stored in the PCM. To obtain an output of diagnostic codes, proceed as follows:

1. Turn the ignition switch to ON. Do not start the engine.

Using SST, connect terminals TE1 and E1 of the DLC1. SST: 09843-18020 Note: The DLC1 is located near the No. 2 relay block. Read the diagnostic code as indicated by the number of flashes of the "CHECK ENGINE" warning light. After the diagnosis check, remove the SST.

If there are no codes stored, we will need to start with some basics. Check for vacuum leaks, give the throttle body and Idle Air Control Valve (IACV) a good cleaning and check the EGR valve.