I just instaled a new big bore throttle body and a throttle body spacer. I ported the spacer to make a smooth transition between the intake and the TB. I used the supplied spacers to move the bracket for use with the spacer, I checked the return springs, I made sure it wasnt binding up, I D.C.ed the battery for a while, checked all connections I put everything on how it was suposed to go on... ect, ect...

Started it, and it idled a little bit high, and when I drove it, first time I punched it the throttle hung open, and I had to limp back to the garage by stabbing the brakes....

Tore it all back apart, checked everything again.

Drove it again, same thing happened. When I got back, I shut it off and restarted it right way, and it was still panic reving. I shut it off, waited about 15 seconds and it was back to normal, just idleing a little high like before.

ANY IDEAS????

I pulled everything back off and put it back to stock cause I need my truck tonight, and now it works just fine... I also closely inspected the TB with it off again, and I cant find anything wrong with it...

Im mechanicly inclined, and have rebuilt plenty of carbs, including a 6x2 set up, so I know how to check for all the obvious stuff, binding, ect... But I dont know a ton about all the electronic side of stuff...

help me out....


Thanks,
Cory


Oh, and its an 03 F150 with a 5.4 auto.

 

I just installed a professional products 75mm on mine and had the same problem but I caught it as I put it back together. The cruise control cable on mine was hanging on the new "mount". I had to sand and file down the mount and took a knife to the cable end and trimmed the inner edges. It still gets stiff when I ease into it, but it is not sticking anymore hope this helps.

 

I checked, and it wasnt that. The throttle body works properly, and the mfg. tech support said it must have been the cables or something binding up on my truck. I really need some new front axles made(porsche 930 inner cv's, custom 5.5" wider per side chromo shafts), a tube bender, KING 18" travel shocks and KING bumps for the rear, so a few extra horsepower isnt worth my time to mess with it when there are other things higher on the priority list... Ill probably just sell it or save it for when I do have more time