Lately my truck has often been nearly stalling and sometimes stalling when shifting into reverse. Does anyone know what would cause this?

I suspected it was the IAC and still think it might be. I cleaned it, but that didn't help any.

 

I'm about to pick up a new Borg Warner or BWD idle air control valve. I hope that takes care of it.

If that doesn't, could the throttle position sensor be the issue?

 

I'm having that same issue with my Bronco, i'll wait to see what solution you come with.

 

TexasGuy, before you start throwing parts at your truck and spending money not knowing if this stuff will fix the issue, here is an offer... I have all good working parts from my 5.0L before the build up. I went back with new stuff, but the IAC, TPS, etc. were all working flawlessly when I tore the engine down. Just an offer. Feel free to come by and try them out to see if any of that stuff will fix it.

 

Back when i had my fuel injection my truck did the EXACT same thing. I put a new TPS on it and it was fixed.

 

Thanks for the tip. Thats good to know.

 

Hey Bud, Thanks for the offer. I'll keep that in mind. How far out there are you?

I still want to come by some time and check out your Bronze F150.

 

I'm about halfway between Austin and Dripping Springs. I work up around 183 and IH35 and that's about a 30 minute drive. I will be in Waco Saturday, but your welcome to come check out the F150 anytime.

 

hey texasguy001, i had that happen to me last year, but mine was going foward and reverse, mostly reverse and idle had dropped from 800 to almost 500. i changed the IAC and it was like a new truck again. i hope this helps some.

 

Thanks for the input traxx. I'm thinking about replacing both of them since they are both over 10 years old and have well over 150,000 miles on them. The IAC looks like its a Motorcraft one, but the TPS is a Wells A'Zone brand.

Does anyone know if the TPS requires dielectric grease on it when installing? I'm pretty sure the Wells one had some on it. The new BWD one does not. I know that when I just removed the TPS to clean up the throttle body it had something still on it.

 

Ha, my 1989 F150 does the other way around, when you put it in gear, any gear from Park when the engine is still a lil cold, the high idle comes on, and it's friggin' annoying. Only does it when the engine is still abit cold tho.

Starts up fine dead cold, revs up for about 2 min, then comes back down to low idle.

 

Thats what mine has always done especially when its cold outside. It still idles high and then comes down after about a minute. Even though it occasionally tries to stall. It will still idle a little higher than normal in gear until it warms up. Those things are normal.

 

Yes, that's part of these trucks ECU programming, that way the engine warm up faster.

 

If it idles up when depressing the brake listen for a slight hissing, I needed to replace a vac. brake booster, the seals were leaking when I pressed the brake, It's funny cause it only did it when it was cold or sat a little.

 

TexasGuy001 did you ever figure out what the problem was? my truck has done this before and I was wondering what the hell it could be