The only screw I have adjusted is the air bypass screw.

The other ones I havenÆt touched.

And ya if you could get the adjustment figures I would appreciate it. I don't see anything about it in my Haynes.






I just took it for another test run. <img src="/forums/images/graemlins/smile.gif" alt="" /> Pepy! <img src="/forums/images/graemlins/drunk.gif" alt="" />

Not familiar with the Amigo, (or my own trooper, for that matter) but on the trooper both the AAV and the coolant temp sensor bypass the throttle, could they be stuck open?

well the aux air valve on my 2.6 is brand spanking new.

but i'm not sure about the "coolant temp sensor bypass"

Steve, this symptom sounds to me like you may have a problem with the temp switch that's mounted on the top of the thermostat housing. There's a hose that runs from the air intake tube to this switch, and from there to the common chamber on the intake manifold. If this switch opens you will get that idle "surging" that you describe. The ECM is monitoring the RPM of the engine. If it sees the RPM going over around say 1600 RPM, AND the Throttle Position Switch is on IDLE, the computer will enter the FUEL CUT MODE (cutting off fuel) until the idle goes back to around 1200 RPM, when it turns the fuel back on again.

It does this only when you are driving ???

What about if you pull off the road when it starts this, and just let it idle ?

Does it stop doing this the instant you crack the throttle open again ? (just enough to get the TPS idle switch open?)

It could also indicate an overheating condition, so make sure that you've "burped" any air bubble out of the cooling system. (Does the heater work OK ?)

One thing you can try that might isolate the problem to that switch: Pull the hose from the air tube to the switch and plug it. Plug the hole in the air tube. See if the problem goes away.

If you have a spare one of those switches kicking around, try a different one.

I know that you know you DON'T want to overheat that brandy new motor, so make absolutely sure your cooling system is functioning properly! (Is the T'stat installed correctly?)

[edit] Check out this article

Article about surging idle

this sound like just what its doing. <img src="/forums/images/graemlins/kewl.gif" alt="" /> i'll check it out.

well i changed it out and no change.

Bob-

I knew it was around here somewhere.

LINK

It will get you headed in the correct direction.

Michael

by the way 19 inch of vacume at idle. now that i set the timming.

i set the TPS and no change.

any other ideas?

Lemmee ask some questions again, answers to these could help diagnose... I'm beginning to think maybe there's a problem with the Vehicle Speed Sensor. Your SPEEDO is working properly, yes ?

It does this only when you are driving (vehicle in motion)??? and if you pull off the road when it starts this, and just let it idle ?

Does it stop doing this the instant you crack the throttle open again ? (just enough to get the TPS idle switch open?)

Are you ABSOTIVELY POSILUTELY SURE that she's not got an air bubble in the cooling system ?? and running hot ?? and that the T'STAT is installed correctly ? (i.e. air bleed hole UP, facing correct direction?)

I would still try the following test, easy to do. If it still acts up with these hoses plugged, then it's certainly not related to that temp switch (I'm still not sure it isn't, even though you changed it).

Pull the hose from the air tube to the switch and plug it. Plug the hole in the air tube. See if the problem goes away.

Does your truck have A/C ? if so, are the hoses to the fast idle solenoid routed properly ?