The car is running really well, but the idle bounces from like 800-1300. It only does it when the car is warmed up. Anyone know of anything that might cause this? Is there anything I can check?
Thanks,
jeremy

 

spray brake cleaner or carb cleaner into the rats nest if your idle goes constant you have a leak somewhere.

 

Carb cleaner in the rats nest. Any other suggestions?

 

check TPS readings and the idle bleed screw

 

what ECU are u running?

 

mI dont want to hijack the thread but mine does the same thing.

I tryed the carb cleaner in the rat nest and it change nothing.

I'm running a power-fc

 

meh? Typically if you have a leak and carb cleaner gets in when you spray it, then the idle will drop momentarily, bouncing back up when you stop spraying

Things to check. Vac hose leaks, TPS, idle adjustment screw on the bottom of the throttle body, clean/re-lube the idle speed control solenoid, check for any leaky gaskets between the engine and the throttle body using the carb cleaner trick (I had this same problem and it turned out that the UIM gasket was missing and the LIM gasket was blown)

 

I'm running a Powerfc. I can get the Idle to go steady by pulling the throttle cable back. Could this have anything to do with taking off the cruise control? It idles at about 900 cold then goes from 800-1300 when it gets warmed up. How do you lube the solonoid?

 

By giving it some throttle you're just masking the problem. The cruise control removal shouldn't change anything at idle since that cable should have been slack at that point any way.

To clean the ISC:
Pull the ISC (off the back of UIM, you're going to have to pull the UIM IIRC so enjoy). Clean it out with throttle body cleaner. Lube with a blast of WD-40. Replace ISC on UIM using new gasket (snag one from Ray @ Malloy Mazda, they're cheap and it'll ensure you're not having a leak there).

This process will also give you a chance to check out the UIM gasket and well as the associated solenoids, vac hoses, etc.

 

Are you sure your idle settings on the PFC are set up correctly?

 

there is another thred here with bad idle. turned out to be either spark plug or wire.

 

There is a good thread in the Archives about adjusting idle and TPS. I suggest you read it and also check the FAQ for threads on adjust and troubleshooting idle

 

I was talking about giving it less throttle. Not giving it gas. I don't know why but instead of going up and down, now it just idles high at like 1500-1600? But pulling back off the throttle drops it down to like 1100 until you drive it.

 

Ah, makes more sense now. Pulling on the throttle cable shouldn't do anything since the line should already have some slack in it. If the throttle cable is taut and pulling the throttle plates open, then you need to adjust it (or find out if it binding etc). Have you tried looking for vac/gasket leaks yet?

 

Yes, I have found no leaks. Next step is readjusting throttle position sensor, but my ohms meter broke. How do I adjust the throttle cable to put slack in it?

 

You can check the TPS readings with the commander, under the ECT menu

vta1 = tps1
vta2 = tps2

 

After verifying that the cable isn't binding on anything, you can apparently adjust the cable tension via two 12mm nuts on the bracket on the front of the TB. I say apparently because I've never done it myself. My guess is that it'll be readily apparent by just looking at it.

 

unless you have taken your tps sensor off you shouldnt have to adjust it, start the car, let it warm up, then put it in first gear see if the idle go down slowly then up then down slowly again etc... if this happens you have a vac leak, Also check the ISC valve resistance to see if its faulty.. if its wack so is your idle

 

No one has suggested that the PCV valve might be sticking open...

 

For some reason the readings on the commander for the tps is backwards. I can adjust it from like .42v and 1.04v all the way to like 1.6 to 3.5 or so. But the measurements seam backwards?

 

So i can get the readings within range but they'll be backwards like tps1 would be .6 and tps2 would be 1.1 or so. Is there any way you could put the plug in backwards or something?

 

If you're worried about the output on the PFC, I'd just grab a multimeter and do it by hand.

http://www.fd3s.net/tps_adjustment.html