Please Help!

[str3etgl0w]

ok so I just put a motor in 02 impala and have never had this happen before, when you start it up it runs good for a few seconds somtimes longer then it will start bucking chugging then stalls it will fire right back up and then the same thing happens. If i unplug the maf it will stay running idles up and down a little but no stalling or bucking I have replaced the maf 3 times! I have replaced all the sensors on the TB I have even replaced the TB! I get no check engine light so my scan tool dont tell me much anyways please I need some help i have been messing with this car a few days and am getting frusteradted

here is a link to my youtube video showing what the car is doing
http://www.youtube.com/watch?v=Y_5dLtLAigw




things I have done
Replaced TB
Sensor
Coils and icm
new plenum and Map sesnor

[Below Average Joe]

vid is private on my end

[str3etgl0w]

ok should be public now

[SJAndrew]

sounds like you're running out of gas. Have you checked fuel pressure etc?

[BillBoost37]

Double check the maf connector for voltage etc. You won't get codes if it doesn't run long. Another thing is to check for vacuum leaks.

[str3etgl0w]

Got gas , I can't find any vacume leaks

[SJAndrew]

I didn't mean you were literally running out of gas. I mean - maybe your FPR is messed up or your your fuel pump.

[str3etgl0w]

Lol I don't have a gauge to messaure it but do you think that would make it run fine with the maf unpluged

[Joe at INTENSE]

Unplugging the MAF makes the car run off speed density, using primarily the MAP sensor. If you unplug the MAF, and it runs, there's your problem. If the MAF is messed up, the computer takes those incorrect signals over everything else. Take away the false signals, the computer switches to "back up" mode. My Park Ave has been running off speed density for a while now after the MAF went out suddenly. Another thing you could try is get a fuel pressure gauge, which aren't expensive and are very handy to have. That would tell you how much, if any, fuel pressure you're getting. Pump could be dying, providing just enough prime to start the engine but not supply it. I'd also test the relay with a 9 volt, just to eliminate that as a cause.

[str3etgl0w]

See I am wondering if its the wiring to the maf somewhere cause yes it runs fine other then ideling a little high at times when the maf is unplugged but I have tried replacing the maf 3 times and it still does it when its plugged in

[BillBoost37]

Scottydoggs can tell you about connectors/wiring getting cooked over the exhaust manifold.