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Discussion Starter · #1 ·
Hi guys,
Will a bad smog pump effect idle right after startup whether warm or cold? If I read right the 02 sensor is ignored for several seconds..but it seems my Trooper will start right up cold/warm either way and it will idle up for about 5-10 seconds then start to stumble and drop down..sometimes it catches itself and the idle creeps back up but its a little rough and most of the time it drops and if I don't rev my engine it will stall..I did check my alternator and got 14.36 volts...New MAF, Fuel regulator pump, filter, coil, injectors etc...just trying to pin point this problem and wasn't finding anything definitive during my searches....To check the pump just listen for the cycle at start up and wait for the relay to switch it off??
Thanks guys!
 

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I wouldn't think so .... There is that check valve where the hose connects. It seems to be a caracteristic of the 2.6's to start and be lumpy/rough for about 40sec's or so. Mine did it to !!
Does the problem go away after it's been running for more than say 5min's ???
I put an after market tps in my amigo amd it always seemed glitchy...Maybe start with the tps at this point...
 

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I would say no, since my 2.6 hasn't had one of those in years and runs fine. have you checked all of your vaccum lines, they can be a PITA.
 

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Discussion Starter · #4 ·
New TPS about a couple months ago maybe....
Vacuum lines are new and double checked..
Thanks guys....its just so annoying when it idles like crap..and yes once you start driving for like half a block the Trooper is smooth with no hesitation or misses etc.....come to a light and its smooth..pull into a parking spot..go inside somewhere for 30 minutes or several hours and come back and start the Trooper and the idle goes up for a few seconds then falls quickly back down..sometimes catches itself and corrects and most the time just drops and dies if you don't give it pedal...
 

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You posted on this already on that other topic didn't you ??
Those systems are so basic it's gotta be something simple I would think.... But yes it's annoying !!!
Mine seemed to quit doing the rolling idle up thing to. I wonder if it's related to the o2 sensor ?? If it's bad the system is in a limp mode and I never really checked mine. I had to put a wire extension
on it when I did the header... Or something has gone bad in the brain.
 

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Discussion Starter · #6 ·
oh I've been battling it for awhile..got a new 02 sensor in there..Im reaching for a solution but I realize it could be anything..If I ever solve it I will post it up so maybe it will help someone else but who knows they could have the same symptoms but a different cause...my alternator is still old and I have yet to swap the ecu temp sensor and idle air valve...It will be the last thing I get too :wink:
 

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Well the idle air valve is just a mechanical part with a bimetallic spring inside. The fact that they are mounted down in the heat area of the motor I think their only cold for the first cold start.
Man always ran good so I never figured it was injector related. All I can say is that with the 92 amigo brain it was much better running/idling.. That system had a map sensor and two controllers like the controllers on the fenderwell for the altitude adjustment. They controlled the egr. When driving the power would decrease and the engine light would come on (like pulling a grade on the freeway) so I figured I'd just put my old brain back in and be done. That's when I noticed the low idle issues. Back when I changed the tps I put it in about the same position as the old one, started it and immediately it was hunting up and down in rpm's. So I loosened the screws and clocked it back to where it idled good. I also had it binding on the throttle shaft and sticking the throttle, by maybe 200-300 rpm. I had to leave one screw slightly loose and it was ok.
The old brain didn't use a map sensor either. I left it hooked up just in hopes that it might monitor the engine better bit I kinda dought it did any reading.
 
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