fbirdserge00

Well my car runs good when cruising or even at part full throttle, but it seems when i slam the throttle and the downshifts it starts picking up, but right about maybe 5k all of a sudden it shuts down and after fires pretty bad. So then i have to stop the car and start it up again and it starts up just fine. I dont know what it can be, im maybe thinking lack of fuel?maybe bigger injectors or fuel pump(oh yeah replaced fuel pump about 6 months OEM). NE feed back will be well appreciated. Thanks.

P.S. Check sig for mods.

pdsq98gt

Hook a fuel pressure guage up and tape it to the windshield so you can see it. See if your fuel pressure is dropping at WOT.

06 SS

if by "after fires" you mean backfires, you are likely looking at an ignition problem. Check wires/plugs/coils.

fbirdserge00

well as far as my ignition goes i replace most of it about 8 months ago brand new oem coils, new msd wires, and oem spark plug wires andit all seems to be in good cond. Dont u think if it was ignition it would act up all the time not only at high rpms? Im going to try to tape that fuel pressure gage and see if fuel press. drops should there be ne give on press.?

MAXPULSE

Post copy of your tune.

jimmyblue

iTrader: (11)

Cat overtemp protection can dump a lot of fuel.
If you have other fueling errors (like excessive
+ trims, etc.) this can compound the overfueling.
COT doesn't take too much time-at-load to wake
up but a long time to deactivate.

fbirdserge00

well i dont have a scanner to post my tune slip, but ill try to get it on here. As far as cats go well i dont have NE on there i had them cut off and had the rear o2s deleted when tuned. i checked my fuel pressure. it was at about 55 psi and drop to about 50 at wot. I also noticed that when i take of from a dead stop at WOT the car will respond fine through all the shift, but lets say im cruing at about 60 mph then gun it, so the car downshifts to 2nd as it starts picking up thats when it takes a **** on me. So its mostly on the hard downshifts when this happens

2xLS1

iTrader: (25)

Check the front battery hold down. They break often and batteries can then rock back on hard acceleration and the Pos terminal can hit the A/C accumulator.

BuffJoeyD

iTrader: (2)

Had this happen on a car where the "Bad VSS RPM" cut off was lower than the other spark cut controls, causing the motor to die. Backfire and would run fine after restarted-

And another where The Battery would slowly come out of the tray after a hard downshift and continued accel