I've recently started having a problem where after I drive my truck a little and I go to put it back in park, when I let go of the brake once it is in park the engine RPM's drop and it dies out. If I try and restart it it dies again unless I give it a little gas, at which point the RPM's drop again, but it catches itself around 500 and then resettles at it's normal idle RPM. What is wrong with my 4.0?

-TJ

 

you running any chips? tuners? A/C?

 

Could be your idle air control (IAC).

Does it stall or act like it will almost stall when coming to red lights or stop signs as your pressing the brake to stop and your foot is off the gas?

 

No, no, and no.

Nope, only when I go to park after driving. How much does an IAC run, and how would I check it? If I can find enough money for my 60,000 mile inspection I might hit the dealer up for it under warenty.

-TJ

 

If it under warranty, take it to the dealer and raise some heck! If it's not, start by pulling the IAC off and inspecting for excessive carbon build up. This sounds more so like a torque converter controller problem to me...

 

I'll add it to my list of stuff to have them do once I do my 60,000 mile inspection and "kick in" my "Customer for Life Benefits". They are gonna have lots of fun cause I'm gonna be wanting a free oil change, free alignment, free carwash, and now they are gonna have to track this down and fix it under warrenty...

-TJ

 

I just found out it happens if I shift into Neutral too..... Wright Brothers better be ready to get their asses handed to them.

-TJ

 

its the IAC Idle Air Controller, just like mentioned above.

mine did the same its $70 i think at the dealer.

you can try and clean it with some Electronic parts cleaner.

 

Have any parts cleaner you reccomend?

-TJ

 

CRC makes some i think, you can get it at autozone i believe or like radio shack etc...

Some say brake cleaner works but id rather see you use Electronic Parts cleaner.

The IAC is under the 4.0 SOHC plastic intake cover made out of aluminum, held on by two bolts.

 

CRC Electrical Contact Cleaner; should be about 4 bucks a bottle.

Cleaning it is only a temporary solution, if that. You may get a week out of it or three months. When these die, you have to replace them. I believe there should be a gasket that needs to be replaced as well when you change the IAC, at least on the 3.0L.

 

hm i might need this to i noticed the same thing but i think its the Jet chip ever since i put it in i have noticed things like that and sometimes when i step on it it takes a sec to really react and kick in...should just get a tuner