Questions and Answers

Toyota Tacoma High Idle, Hesitates Q. Hi, I own a 1998 Toyota Tacoma 4x4 with a 2.7 liter 4 cylinder engine with 106,000 miles. The problem I have is that when I am driving on the highway at around 60 to 63 mph, it will hesitate strongly for about one second and make a kind of "putt" noise. Sometimes it happens again, other times it won't do it again.

It will also do the same thing when I am accelerating strongly. When I let the car sit and idle, the idle is higher than 1,000 rpms and then it sounds as if the engine is misfiring a little. I changed the spark plugs and gapped them properly. I also changed the spark plug wires, fuel filter and air filter. I checked for vacuum leaks, and changed the PCV valve.

If you have any ideas I would appreciate them greatly and thank you for your help, your web site is great.

A. This one will be a little difficult to track down. I would check the PCM for any stored codes. Maybe we will get lucky and there will be one there that will help diagnose the problem.

Other than that, I would test the Throttle Position Sensor (TPS). It may have a "dead" spot and if it does, it will cause the symptoms you describe.

After that, it will need to be driven with a scan tool connected to see what happens when the hiccup occurs.