Erratic idle, TPS replaced, now what?

[96sportage]

1996 Sportage 4x4, 2.0 DOHC,

OK I had an erratic idle, so I regapped the plugs, no fix...................

I replaced the Throttle Position Sensor, no fix......................

When I unplug the TPS, the engine runs perfect, except for an extreme high idle but without any stumble, or falter, which I assume is normal when the TPS is unplugged,

So whats wrong????? What did I miss?

[ron1004]

Welcome to the forum.

What plugs are you using and what gap?

It is possible that the Idle Speed Control actuator (ISC) is faulty - often taking it off and cleaning it with carb cleaner sorts it out.

[96sportage]

That Idle Control Switch is brand new, I know a lot of you guys think thats a good idea to clen them, when they go they go, and no amount of cleaning will help when they fail. I tried cleaning the original one before I spent the 150 bones to replace it.

The gasket on the air intake pipe on the TB was crack causing a vacuum leak


That vacuum leak was the problem so folks check ur vacuum leaks and pressures if u have erratic idles first.

Im sure the TPS needed replacing anyways considering it was factory and had 162k on it.

[ron1004]

Originally Posted by 96sportage

That Idle Control Switch [valve] is brand new, I know a lot of you guys think thats a good idea to clen them, when they go they go, and no amount of cleaning will help when they fail. I tried cleaning the original one before I spent the 150 bones to replace it.

The gasket on the air intake pipe on the TB was crack causing a vacuum leak


That vacuum leak was the problem so folks check ur vacuum leaks and pressures if u have erratic idles first.

Im sure the TPS needed replacing anyways considering it was factory and had 162k on it.

You didn't mention the new ISC.

It does make sense to suggest checking the ISC based on the symptoms described.

The ISC often gets contaminated by deposits (likely via the EGR) and cleaning with carb cleaner sorts them out in this case, but is obviously not the cure for a failed ISC.

A word of advice to those seeking help with a problem - post as much detail as you can.

[ron1004]

Here's a good tip regarding vacuum leaks on the sportage.

http://www.kia-forums.com/1g-1994-20...esel-paul.html