Originally Posted by ishsgt
I have a 200 F150 with the 4.2 liter and recently it started surging, shaking, and bucking. Especially at idle. It runs good at acceleration. I cleaned the throttle body, checked for vacuum leaks, replaced the MAF sensor, and replaced the IAC motor. I got the code MAF out of range, Bank 1 lean, and Bank 2 lean. After clearing the codes the Check engine light has stayed off. I have aslo diconnected and reconnected the battery. Any suggestions on what it could be?
Harmonic balancer? (spelling) Almost the same problem but mine would only do it while in drive, put it park and it was fine, step on gas and didnt have any power at all and then it would do better once i got up to speed.
Well the keyslot on the "Harmonic balancer" was twice the size as it should be and it caused the timing to be off.