Start/Idle problem

[comanche38]

Hey guys, I have a problem that I can not fix. I have a 1988 Comanche that has the 4.0L, auto trans and np231, in case this helps. The problem is that the jeep will start but after the initial high rev start up it will stall. This first started to happen when we went to Drummond Island. It was hard to start but after putting it gear it seemed to be O.K. and would idle fine. Then it would get hot (another issue that I will address) and start the same symptoms. I would turn it off and then at startup it would do it again. I replaced the tps, as I was told this is the problem, but there was no change. I can't even get it idle at all now. Anyone have any ideas?? :roll:

[pingpong]

More thenlikely it is the Idle air control valve. That is if you are getting good fuel and spark. I had a fuel pump go bad.. and it would start up fine, then once you gave it gas it would choke out.

[JOMJ87]

Its prob the IAC but the replacements i have found have been in the mid $100 range so i didnt replace mine. You can try to adjust the idle up with the bolt on the front of the IAC. Hope this helps.

 

Cole

[87manche]

I read somewhere on NAXJA that there's a universal Holly IAC that will work for the 4.0, and it was something stupid cheap. $30 springs to mind. Might try searching on that.

[ORCA]

When was the last time you changed the fuel filter? You can get new Fram ones at Kragens, but I forget how much they are. Easy to replace too. :cheers:

 

You may consider replacing the fuel pump, after you've done everything else and it is still acting the same way. My truck had similar problem and it was the pump ;)

[JOMJ87]

I read somewhere on NAXJA that there's a universal Holly IAC that will work for the 4.0, and it was something stupid cheap. $30 springs to mind. Might try searching on that.

 

I have the 2.5 :oops: and yes i know but i don't have to many complaints with it.

 

Cole

[87manche]

it wouldn't surprise me if it was the same motor, it was the same control system, and I know a 4.0 TB will fit a 2.5.

[Stumpy]

When was the last time you changed the fuel filter? You can get new Fram ones at Kragens, but I forget how much they are. Easy to replace too. :cheers:

 

You may consider replacing the fuel pump, after you've done everything else and it is still acting the same way. My truck had similar problem and it was the pump ;)

 

got mine at Wal*Mart

[comanche38]

Thanks guys for all the pointers. I replaced the fuel filter not too long ago, but had a little run in with a homemade gas tank gasket. (I misplaced the factory one and made one, that disinigrated) I will replace this and will see if that does it. Again, Thanks for everything! :cheers:

[87manche]

for thse that I teased earlier.

"holley part #543-105 is an idle air control motor for holley's pro-injection system," and is a direct swap for this part for around $28 at AutoZone vs. $125+ at the dealership!

[ROADLESS]

You may also have a bad EGR solenoid or valve. I would check for this next if the problem still persists :hmm: .

[JOMJ87]

Just a small Threadjack:

 

I have one more question, would the TPS cause my MJ to run Rich. I am thinking it might be one of my problems but i was unsure exactly if it would cause the truck to run rich.

 

Cole