I have a 1990 f150 5.0 and i just got it and it runs rough when idleing it will hesitate like its going to stall but it doesnt, i put a new rotor and cap on it and i put fuel injector cleaner in the tank and that made it idle better. Tomorrow im going to put new wire and plugs on it. Any ideas?

 

u watch to much american idol....

 

HELL NO!! i would never watch American idol and what's that suppposed to mean.

 

its spelt idle...

 

Well what ever, any ideas? I replaced the plugs and still no change, will change spark plug wires soon just ran out of money with buying the truck and all.

 

Clean the throttle body (just for good measure) and the idle air bypass (IAB) valve mounted on the side of the throttle body. Caveat: I am more familar with the 5.0 Mustang than the 5.0 in your P/U, but I believe the procedure should be similar. Remove the IAB and seperate the electronics from the mechanical part of the valve (be careful not to lose the "O" ring). Move the plunger while spraying carburator cleaner on it until it moves freely. Also, clean the two holes in the TB that the plunger opens and blocks. Reassemble and test.

 

Looks like a nice truck. Has it been sitting? That could cause those type of problems. Could be you just have to do some of that maintenance.


Josh

 

Yea im guessing it has been sitting because it was at a used car dealership for a while, well ill drive it and if it persists ill just have to bring it in to my mechanic, Any ideas will still be a appreciated.