masterhayes

so my 97 mustang gt has an engine hesitation only when im driving not while idling. it doesnt matter if the car is hot or cold when i step on the accelerator it hesitates. the car only has 126k miles on it.
ive replaced the purge flow sensor, purge flow solenoid, flushed the fuel injectors, checked the egr valve which is working fine. i have also gutted the cats and checked the fuel pump which also is working. ive replaced all spark plugs and wires. changed the fuel filter and put in a new maf. there are no vacuum leaks either. i have no codes that are popping up. i have no idea what could be causing the hesitation

HouTx97GT

Im having these same problems at the moment. I recently almost ran my car out of gas the other day. Ever since its been hesitating under acceleration. I have only replaced the fuel filter so far. Im hoping i didnt kill my walbro fuel pump, is there any way to check it without dropping the tank?

masterhayes

yeah you just need to get a fuel pump gauge and screw it onto the nozzle on your fuel rail line. then just turn your car on and you should be getting 30-40 psi

HouTx97GT

Have you found your issue MasterHayes? I have recently changed my fuel injectors, the fuel filter, tried replacing the AIC, the fuel pump is working fine. Do you think there could be a link with this to the clutch possibly slipping?? I have a manual, not sure about yours. Because I have an intermittent problem, depending on how i work the clutch sometimes is hesitates and vibrates as i try a hard acceleration from a stop, and sometimes it peels out just fine. However, when my car is idle, I can hear random exhaust drops/surge noises but its not terribly bad...I am stumped.

masterhayes

hey my car is manual and i figured out my issue my fuel injectors needed to be replaced and my clutch needed to be replaced and now my car drives better than when i bought it. for your issues you may want to check your maf. also i gutted my cats and that helped with acceleration big time. it sound like you either have a fuel/air issue or exhaust issue. do you have any codes popping up

HouTx97GT

I have tried cleaning the MAF, and checked the power voltage coming from the connectors. Is it possible the MAF could just go bad? Something I just ran across on here for my issues could be the Fuel tank baffle. I think this might be it seeing that all these issues started from running my tank almost empty. No check engine light nor will my X3 pick any codes up. Thanks for the help!!

HouTx97GT

Ok so it looks like the best way to test for a broken fuel baffle is taking a hard right turn, i tried it in my neighborhood in 2nd gear, hard right turn with acceleration and no hiccups...

HouTx97GT

So after having a compression and leak down test I found out I have a burnt exhaust valve