Hey guys. New-b here. I have bashed my brain in trying to diagnose this issue. Here is what I know.
I picked up a 95 GT two days ago, and I've been going through the car fixing small problems. This one is turning out to be a large problem. The car has a BBK intake, and flowmaster cat back. Otherwise stock.
Symptoms:
Drives fine under normal(conservative) driving, even got 21 mpg.
It will rev fine all the way to the limiter if you rev it slowly
If you stomp the pedal from an idle it will rev perfectly until 4,300rpm then start "missing?" and backfire through the intake.
If your driving normally and stomp the pedal it will pull fine until 4,300 and do the same
Bogging the car at slow speed in any gear and going full throttle, it will just pull no problems, until...you guessed it, around 4,300rpm, then hesitation, missing, studdering, and popping from the intake.
Things I have done:
New motocraft plugs gapped at .049
New MSD cap and rotor
Run premium fuel
Checked timing at 10* advanced to 12* with no change.
New 8mm MSD plug wires
Ignition module tested ok by mechanic
Coil tested ok by mechanic
Fuel pressure is 39-45 psi depending on rpm/load
Cleaned MAF with proper cleaner
Verified sparkplug wire firing order on dizzy
Ran cylinder balance test and got 9 flashes = everything ok
NO CEL!!!!
It does this every time you get to 4,300 rpm at full throttle. Doesnt matter what gear Im in or if Im sitting still in neutral.
Do you guys have any ideas?
Thanks in advance!
I picked up a 95 GT two days ago, and I've been going through the car fixing small problems. This one is turning out to be a large problem. The car has a BBK intake, and flowmaster cat back. Otherwise stock.
Symptoms:
Drives fine under normal(conservative) driving, even got 21 mpg.
It will rev fine all the way to the limiter if you rev it slowly
If you stomp the pedal from an idle it will rev perfectly until 4,300rpm then start "missing?" and backfire through the intake.
If your driving normally and stomp the pedal it will pull fine until 4,300 and do the same
Bogging the car at slow speed in any gear and going full throttle, it will just pull no problems, until...you guessed it, around 4,300rpm, then hesitation, missing, studdering, and popping from the intake.
Things I have done:
New motocraft plugs gapped at .049
New MSD cap and rotor
Run premium fuel
Checked timing at 10* advanced to 12* with no change.
New 8mm MSD plug wires
Ignition module tested ok by mechanic
Coil tested ok by mechanic
Fuel pressure is 39-45 psi depending on rpm/load
Cleaned MAF with proper cleaner
Verified sparkplug wire firing order on dizzy
Ran cylinder balance test and got 9 flashes = everything ok
NO CEL!!!!
It does this every time you get to 4,300 rpm at full throttle. Doesnt matter what gear Im in or if Im sitting still in neutral.
Do you guys have any ideas?
Thanks in advance!