Took the front O2 sensor out. Same thing. I even did a back pressure test and not even 1/4 psi of back pressure. It almost feels like someone shuts off the ignition for a split second and turns it back on. But only under full load???
You mean at idle?
Someone else will need to be in car pressing gas while you spray fuel into the throttle body then you can see if you can get rpm above part throttle. If that only happens under load let me know. Thanks.
When the car is not moving, I can get the rpm to increase all the time. Also, when I put it in gear and press the brake down and hit the gas pedal it goes to torque converter stall speed without hesitation. Only when under real load and heavy acceleration it will surge and eventually reach full rpm.
No, nothing recent. And no misfire codes. ST and LT trim are all ok as well.
Yes. At idle, no misfire. In neutral at any rpm - no misfire. Whne it surges under full load, it will give a 1 misfire count randomly, but no repeated misfires.
There are no spark plug wires as it is coil on plug. If the ignition were the problem, would I not see multiple misfires.
I will do as you suggest. Just one question though. If the ignition module were bad, would I not see misfires on the monitor?
Ok, cannot find a MAF on this engine. I changed out the ignition module and confirmed a good ground. Still the same. One thing that is interesting. Once I am in cruising mode, I can give it full throttle and no hesitation or surge. I even tried disconnecting the VSS - but still the same.
First let me say that the professional here, Dan, was very helpful and timely and deserves an excellent rating. Some problems, especially sight unseen, really are difficult to solve and I feel he withdrew only to see if someone else could help.
Yes, I would still like some help. Thank you.
Thank you for your answer. I hooked up a fuel pressure gauge while driving and sure enough the fuel pressure drops drastically when the surging is present. I have ordered a new fuel pump.