Hawkschwier

My 89 Mustang misses under 2500 RPM while driving and while in neutral. The whole car shakes when it does it in 4th and 5th gear. But when I hammer the gas it goes just fine. I just can't drive around everywhere hammering it in constant acceleration. I have replaced everything. Plugs, wires, distributer, new fuel pump, new injectors and more. But i do have new heads, intake, throttle body, fuel lines, fuel pressure reg, 02 sensors. ... No EGR. Had to get rid of it. Its timed right. Lots invested. Any ideas would help.

aode08

When you installed new heads, the ground wire for the o2s are on the back of one head, it always breaks are is severy rusted, repair this and make sure it has a good ground.



I would then clean the MAF sensor and test its voltage, and disconnect the white and black salt and pepper shakers, inflated the pins using a center punch, then push them back together and check for moisture.


The throttle position sensor could have a bad spot up to 2500rpm.

Check for a clogged fuel filter