Hesitates, no power, stumbles, runs sh*t rich

[LS1toSVT]

Ive been dealing with this $*** for a month now... and Ive had it.

Mods: whipple 3.0 pulley, 60's, K&N, MAFia, BAP, Accufab, o/r xpipe, flowmasters.

Car ran solid for a month with that setup. One morning I started the car and noticed the hesitation when starting off in first gear. Problem gradually progressed to constant hesitation, power loss, stumbleing.

Problem:

o2's are pegged(.98ish) at idle, fuel trims are pegged at -25% trying to pull out fuel. ALL plugs are black, car hesitates at any rpm, stumbles under boost. Lacks ALL power.


Checked so far:

MAF's were switched
new tune was written without MAFia
EGR system was removed
No vac leaks
TPS is set at .99
IAC was removed/cleaned
FRPS was replaced
No misfires
Brand new PCM was installed
FPDM was swapped with a working unit
Plugs were replaced, now they are black
Fuel filter was changed
switched tunes

Fuel rail pressure is normal
ECT is normal
IAT's are normal
TPS is normal
VAC is normal


I dont know what else could cause my car to run like this. The problem went from random, meaning it would hesitate, then 20min later run perfectly fine, to constantly like this.

[Viper_ed]

Have you tried bypassing the BAP? Maybe something is causing it to max out the FPDM. Did you cut or shorten the RCA Cable that runs to the switch for the BAP? I know that there is a certain resistance value that the BAP sees from that switch that has something to do with the length of the wire.

I'd also try running it with the stock injectors instead of the 60's. Maybe something is either wrong in the tune or you may have an injector hung open or something like that.

[Wolfpack Speed]

double check your o2 connections and verify your sensors are good. your symptoms are exactly what happens when the o2's are bad...good luck!

[LS1toSVT]

double check your o2 connections and verify your sensors are good. your symptoms are exactly what happens when the o2's are bad...good luck!

I will look into that. Is there any way to test the o2's? They do move/sweep during part throttle/cruise speed. And when I pull a injector harness off the driver side, that o2 leans out. So Im assuming they are reading whats actually going on.

Have you tried bypassing the BAP? Maybe something is causing it to max out the FPDM. Did you cut or shorten the RCA Cable that runs to the switch for the BAP? I know that there is a certain resistance value that the BAP sees from that switch that has something to do with the length of the wire.

I'd also try running it with the stock injectors instead of the 60's. Maybe something is either wrong in the tune or you may have an injector hung open or something like that.

Bypassed the BAP. Swapped FPDM's. Didn't touch/modifiy the RCA cable or BAP. I tried different tunes from different tuners, also with a brand new PCM. And the problem is global, as in all 8cylinders. So if one injector was stuck, all 8 plugs shouldn't be going black. Correct?

Keep em coming guys. Anything you can think of.

[Chris00GT]

I'd remove the chip/tune go back to stock and install the stock mass air meter and injectors and see if she runs better.

Hmm this one even has me stumped. You've replaced or checked most things that we'd look at The only other thing is do a leak down and compression. M t with it being radom it has to be an electrical gremlin. Didn't you have the car down at our shop(Kauffman Motorsports) to have us try to figure it out?? Sorry we get alot of car with problems and it's hard to remember.

[LS1toSVT]

I'd remove the chip/tune go back to stock and install the stock mass air meter and injectors and see if she runs better.

Hmm this one even has me stumped. You've replaced or checked most things that we'd look at The only other thing is do a leak down and compression. M t with it being radom it has to be an electrical gremlin. Didn't you have the car down at our shop(Kauffman Motorsports) to have us try to figure it out?? Sorry we get alot of car with problems and it's hard to remember.

The mass air meter is stock. I just have a MAFia. Also, I tried 3 different tunes. I can definitly say its not the tune/PCM. I was thinking about going back to the stock injectors, but I need 60's for my setup, and I can't see all 8 60's going bad on me. It has to be something telling the 60's to run rich. Last resort will be going back to the stock injectors/tune.

RWTD sent me a tune that disabled the LTFT's and the "adaptive stratagies" in the PCM. I then logged the car at 500rpm incraments for 15seconds. Sent them the file and they went over it. James from RWTD confirmed that the tune is solid. But the car still runs like crap.

And your right, I've checked/replaced damn near everything possible. The only things I haven't swapped out are the TPS(which is showing proper voltage), the o2's(which respond accordingly from what I can tell), the injectors(which can't ALL be bad).

I haven't brought it to Kauffman's, but thats not out of the question right now. I may have a new friend(thanks PJ) that may be taking the car off my hands and is going to try to trouble shoot it in his free time. Because right now I dont know what else to do. I can't afford to just keep replacing things that aren't showing up as a problem. I have a new FPDM on the way to my house, and thats been ruled out already. Anybody need one? lol

I hate the world right now.