High idle problems continue........

[Led]

Ok, took it for it's first run after the new sensors.........

Now the damn thing won't fire up unless I put the gas to the floor EVERYTIME I wanna start it! WTF? It won't fire at all by just turning the key.




Nope, but again, can you tell me why the MAP would be causing these symptoms? Doesn't help much to test the voltage on something that isn't related to the problem - not being a jerk here, just wanna learn the thought process behind the suggestions, ya dig?

Truggy did that for a few days after I swapped the injectors, gave up one day went home next day it fired right up. good luck. played the swapping parts game never could pinpoint or recreate

 

[JJacobs]

This is one of those situations where live data is irreplaceable. Troy, as many Jeeps as you get through the place you should have picked up an old Snappy MT2500 brick by now. It'll do Renix and both OBD's with the right pieces. I have to wonder about injector leakdown with your latest issue, pedal to the floor is clear flood mode and stops the injectors to clear excess fuel.

Generally speaking high idle is symptomatic of a vacuum leak, but xj's do weird things that don't always follow convention. Loose TPS connections have given me high idle fits.

MAP does of course contribute to the puzzle, but generally a vacuum leak to the MAP makes the pcm think the engine's under more load and increase the fuel, giving other symptoms like low idle, black smoke, poor fuel economy and lack of power.

With no scan tool, the best approach is to bust out a diagram and look at everything. Which sensors take 12v and which are 5v vref from the pcm. Are they getting the appropriate power and ground? Backprobe the pcm connector at the signal wires, do you get a good sweep out of the TPS? The coolant temp sensor? And so on..

 

[YELLAHEEP]

MAP does of course contribute to the puzzle, but generally a vacuum leak to the MAP makes the pcm think the engine's under more load and increase the fuel, giving other symptoms like low idle, black smoke, poor fuel economy and lack of power.

That's pretty much why I wasn't suspecting the MAP. It runs just fine - just idles high. When I'm driving, it runs great! Plenty of power, no rich smell from the tailpipe when idling or under load.

Started it this afternoon and it did fire up without having to use the pedal, but it sputtered and hesitated for a couple seconds. Subsequent starts - it fired right up...... and stayed at high idle.