OK here goes. Last week I was pulling into my gym parking lot and my L just shuts off. I cruise into a space, shut everything down and put it in park. Starts right back up.

-Next day I have appt. with dealer for other warrantied things and mention the L losing power. says he will look at it.

- Have had it back a week now and the very 1st day I had it.......boom...dies again!!!!


-Today....died 11 times while driving. Cruising is fine...low idle...it goes. I was parked a couple times and waited in traffic a couple times and it just died.

-My dealer said he replaced some vacuum lines and a gasket and said I'd be fine.

-I checked my chip, Boost bypass, and filter and all were fine.

-What gives man??????????????? I'm really starting to dislike my L. I will be taking it back to my dealer tommorow.

-Anyone have an idea??????????

 

Check the IAC valve and clean it.

Run a search to find a how-to on cleaning it.

 

https://www.f150online.com/forums/sh...ghlight=IAC%2A

there you go!

 

Your chip is loosing its connection. Not enough clamping force to grip the PCM board reliably. Take it off and drive it for a few days. If I'm correct, send it back for a replacement.

Dan

 

Well my dealer replaced mine a week ago(IAC). So he said. I'll try cleaning it and reinstalling the chip. Thanks guys.

 

ogieogilthorpe:

About a month ago was pulling into the local ford dealership to pick up some wiper blades...as I'm pulling into the parking slot
the engine dies...period. The engine would crank but NOT hold idle. The month before they replaced the iac in an attempt to resolve this "cokebottle sound"(prior posts). Well it so happens that a mechanic looked at it right then...found out the other mechanic put on the "WRONG IAC"...so he put a new Lightning iac
on...started just fine...ran fine...SO there is a different part number for the standard f-150 iac and the Lightning iac...make SURE they put the CORRECT IAC on (they have a different plug pattern). I suspect your problem is the iac...good luck.

 

Thanks a lot guys. I just took the IAC off and it was clean as a whislte and looked brand new. Don't see a part # on it now. I'm takin my chip off right now and cleaning the contacts and putting it back on. Part # for the IAC anyone?

 

ogieogilthorpe:

The dealer may have put the wrong iac on your truck...just
as in my case...the standard f-150 and the Lightning iac look
much alike...BUT they are different. I bet they put the wrong
unit on.

 

Ok the part # i have is as follows for IAC.

-2CQSR1
XSZE
SF74588

I took it off and it was fine...cleaned contacts and reinstalled my chip. Car is runnign out front as I type this. I can hear the truck running out the window. 5 minutes ...so far so good.

 

ogieogilthorpe:

The part number for the IAC as listed on my invoice is-

F67Z*9F715*BB (this is the correct one)

I will go out to my truck to verify.

Remember that the proper IAC is for the supercharged engine.

 

ogieogilthorpe:

I could not see any part# on the IAC...but I remember that the
mechanic told me that you can tell the difference between the two by where the plug attaches to the IAC...on mine the plug contacts are on the very "outer edge" of the IAC "barrel"...I believe that the wrong IAC has the electrical plug contacts near the "center" of the barrel...hope this helps. Also note that mine is
a 2001 Bolt...Dont think this matters but you need as much info as possible.

 

I'd go with the chip theory. My PCM contacts are too scraped, and 1 of my 2 chips will lose contact and the truck will die. You have to either get a brand new chip (still may not fix it), or have someone build up (slightly) the contacts on your PCM with soldier.

 

Iwouldn't touch the PCM contacts. His chip works until it looses its clamping power, so it won't matter if the contacts are clean--and they are, because it worked--until now. If the PCM strips weren't 'clean', it would have never worked.

I have 3 different chips. One of them has caused my L to 'die' several times. Removed that chip and installled another make and it ran fine--everytime it happened. It's not the PCM contacts--I'll bet.

Dan

 

Ok my truck runs fine now. All I did was reinstall the chip and remove the IAC and put it back on. I'm still gonna go to my dealer to make sure he put on the right one.

 

I had the same problem I was going along the road just fine and then boom the thing died. I rolled off to the side of the road and I could get it to crank over but then it would just die again. It got towed into the dealer and then the dealer was able to start it up just fine. Eventually they found that the fuel pump was bad and it had to be replaced and that solved everything my truck has 16,000 miles on it and running just fine.