99gtstang

Ive got a 99 gt few mods, X-pipe, intake and pullies. Lately when i drive in any gear the car jumps almost like it is skipping. Especially while the car is under a load. Such as up a hill or staring in 1st gear. Also I can be driving steady at 75 and it will just jerk once or twice. Drives almost like a bad coil pack. But i am getting no check engine light. Heres the funny part if i throw alot of fuel injector cleaner in it, it will slow down or quit. Ive replaced plugs, springs, and boots. Ive been reading your forums and you guys have got the best anwswers so this is my first post. Thanks

Car has been to a shop and on diagnostics and they say nothing is wrong.

Cornbread01

did you try the fuel filter just a sugestion
or try to reset the computer unplug the battery for 5-10 mins reconect see if its better

97 5.0L

probably alot of other people on here know better than me but could it be gears or transmission?

99gtstang

Yea filter new

99gtstang

Not sure car does great on that new clutch, no slipping, doesn't feel like rear end for sure in the motor.

99gtstang

Will reset everything and see what it does..........

Cornbread01

when i did my filter it ran like crap afterwards cuz i didnt diconect the battery... you have to do so so that the comp can adjust the a/f ratio you probablly getting to much fuel my car did the same thing after reset the comp ran fine hope this helped

mustang_montana

need some more info. first, did it just randomly start doing this, or did it do it after a "mod"? second, describe whats going on, is it bucking while on the throttle or comming off? i really dont quite understand what youre saying, is it bucking under acceleration or part throttle? could be intake related but i really need more info.

99gtstang

its been doing it since i bought it... on and off for a few months. Lately alot more. Only when you give it gas not downshifting or letting off the gas. Does it under light and heavy pressure to the gas pedal. It stutters, drives just like a coil pack went out......hard to describe. Jerks the whole car and taking of in first its struggles almost like its not getting gas. I put a screwdriver to the injectors there all ticking i dont know if that means there working properly. Could it be timing? or could the timing chain be stretched out? maybe the cam caps are loose? Thanks for your replys

99gtstang

Yes it did it before and after the mods....