94 2.3 idle control

[wr250rdr]

Does anything other then the idle adjustment screw control the idle on these motors? I'll set my idle at approximately 950 (warm) and it will try to idle around 650 cold. I have done all the basics I don't have a vacuum leak that I can see or find with the ether test. But I'm not 100% sure that it's all routed right. If someone could chime in on what all gets vacuum I could eliminate this as a possible cause. The connections I am unsure about are on the passenger side of the bay. Also I do not get a code at all.

Thanks for all the help guys

 

[Bryanp66]

You might have a bad Idle Air Control valve. This valve is what regulates the idle. The adjustment screw is just for reference in regards to the what the Throttle Position sensor reads as normal idle position. If your IAC valve is bad you will probably find that you will have to readjust the idle at the screw so the TPS is getting the right reference. You could have a bad TPS. Normally, the adjustment screw does not need to be changed from the factory setting.

Bryan

 

[Bmazda]

Sometimes the Idle Air control valve can get gummed up, I would remove it and clean it out with carb cleaner before replacing it. Also the Throttle Position Sensor like Bryan mentioned could be bad and can be easily tested with a volt meter.

 

[Bryanp66]

Yes definitely take the IAC valve off and spray it out good with carb cleaner. Also, you might want to check the electrical connection at the valve. Check and possibly clean the contacts on the connector and the vavle. Usually, IAC valve will give erratic idle, stick the idle up when driving, etc. They can be tricky to diagnose because they can be bad and not throw a code. I just replaced one on my 95 that was as clean as a whistle, but wasn't working right. If your idle is steady at 650 and the IAC doesn't help, I would look toward the TPS. The TPS can be working, but be "lazy". Sometimes it is not enough to throw a code. On your 94, that sensor should be non adjustable, while the earlier ones had a resistance adjustment that would affect idle speed. This is good, since you have messed with the idle speed screw. In the event you end up replacing it and is the problem, you will just have to reset your idle screw and the TPS and IAC will pretty much do the rest. Let us know what you find out and if we can help you further.

Bryan

 

[Bryanp66]

Also, try disconnecting the IAC valve and see if the idle changes. If it is working, you should see a much worse idle. It really sounds like it is not working at all. Be careful with that connecter though. Those plastic connectors get brittle on these old trucks and the locking tab can break very easily. You shouldn't have to set your idle at 950 warm. That is way too high. I am assuming you have to do that to keep it running cold.

Bryan

 

[wr250rdr]

Is there a test process for icv When I have it off the truck?

The az by me wants 100 bucks for a new one and I'm cheap and have a decent bone yard that I could pull a dozen for that

 

[rangergi]

I don't think it would be ur tps because when my tps went bad it threw codes, ran very rich, and had trouble starting. But it's worth the check

 

[wr250rdr]

So finally got the icv off and cleans and that seams to have fixed the issue at idle. But I am experiencing the same problem when costing to a stop, out of gear or with the clutch in. It will bump between 1k and 600. Any ideas?