Mystery problem

Past couple of weeks now I would go outside to start the jeep and it would start to crank and then die like it had a dead battery. I would turn the key off and back on and it would start right up. Had the battery and alternator tested and both tested fine. Tonite I went to start it and it cranked for about 2 seconds and died. When I started it back up, the CEL came on but it was running fine. I drove to an unmentionable auto parts dealer and had it tested. It threw a P0505, IAC Circuit Condition or idle speed higher/lower than expected.
This wouldn't cause the aforementioned starting issue would it? This thing is driving me nuts...

It sounds like 2 different issues. The IAC issue could definately cause the stalling issue.

As for the starting issue... I would check, clean, and tighten the battery connections including the ground connections. Check the connections at the starter solenoid as well.

doesnt the iac set its position when you turn the car off? so like if its broken, its not reseting itself properly to startup the next time, then when you try to start it unsuccesfully, maybe its cold and feeling good, so it resets, allowing you to start it up round2?
maybe grab a new iac, or try a spare?
be glad you have a proper on board diagnostics!

Sounds like the starter is going.

starter brushes are welding. Probably getting close to time for a new one.

RichP said:

Sounds like the starter is going.

Click to expand...

x2 Check you grounds too.

It does sound like you have two separate issues...

I had the cranking problem you are describing, turn the key and the starter engages and turns the motor for a brief second and then quits.... Mine was very intermittent and it took me quite a while to actually catch it with test equipment..... what was happening is the ignition switch had a faulty contact..... when you turn the key and this problem happens, hold the key in the crank position even though it isn't cranking any more and then wiggle it or turn it slightly more and slightly less..... If it then cranks, it is a good indication that you have the same problem.... The other test is to use a volt meter or test light and make sure you have 12v to the small wire terminal at the starter.... this is the terminal that gets the signal from the ignition switch to crank.... if you dont have voltage there, pull off you column covers and test this signal right at the ignition switch....

As far as the other, it is probably a bad IAC