help

[Vsicks]

Hello, anybody with from the chicago or west burbs that knows how to work on these cars. I tried to fix my car but it continues to lose boost when i give it gas and sometimes it backfires. i tried change mass air flo sensor i need help.

 

[Frederickdav]

Do you have a Scanmaster?

 

[Vsicks]

yeah, was showing 42 but i disconnected battery and it went away. going to try a new ignition module and coil pack as soon as i get it

 

[GNRick]

If I remember correctly a bad tps sensor will cause a backfire. Hope you get it sorted out. Turboburick on the forum is an hour south of Chicago.

 

[Vsicks]

hmmm ok ill get a new yeah its backfiring and turbo sputtering sound at about 20-25 miles ill try a new tps sensor.
ok thanks for your reply

 

[VtheGNMan]

Hello, anybody with from the chicago or west burbs that knows how to work on these cars. I tried to fix my car but it continues to lose boost when i give it gas and sometimes it backfires. i tried change mass air flo sensor i need help.

New MAF? What one did you get? Parts Store MAF's for these cars are notoriously bad out of the box for these cars. They use a MAF from a different car/engine and they flat out don't work. Unless you swapped with a known good MAF or went to new gen with a Translator, I'd go back to looking at that as your suspect.

 

[Vsicks]

lt1 maf i use the translater plus? ok ill check that out as well
thank you for your help

 

[VtheGNMan]

lt1 maf i use the translater plus? ok ill check that out as well
thank you for your help

You should be fine then. I'd be looking at coil pack and ignition module too then.

 

[TurboBuRick]

If you are loosing boost, its more likely that the fuel pump is not delivering enough fuel.
How old is the fuel pump? Is it hot wired?
Watch the o2 millivolts when you get on it. If they drop to 0, it's going lean.

 

[Vsicks]

first i would like to thank you guys for the replies and feedback
pump is about 5 years old with a hotwire kit. car its running terrible. it has strong unburned gas smell. swapped out the mass air sensor, control module and coil pack its doing the same. this is what my what car reads :
MV 400,
Maf 7
lv8 33
volts 13.2
INT 128
BLM 142
coolant 174
air temp 101.5
rpm 1400-1425
TPS 54
IAC 36
02CC goes from 164-252 then as low as 02 then back up ....

 

[TurboBuRick]

Tps is too high. That's going to mess with the idle. Adjust it to .40-.42

O2 mv is reading lean. The blm is adding fuel when it in closed loop. So I don't see how it could be rich unless you have a bad pre o2 exhaust leak. The o2 sensor could be bad but the cross counts are active so this is unlikely.

 

[GNRick]

Check for gas leak around fuel rail, fuel pressure regulator, fuel filter. Maybe a bad injector is causing the car to run bad. Maybe the chip isn't seated properly. If the car idles rough you can try wiggling wires at the ignition module, injectors, and ecm to see if a wire is bad. Check the ground wires. Easiest one is the wire from the battery to front of block. Our 30 y.o. wires are deteriorating. I replaced my whole engine harness and injector harness last January. For some reason my car was shutting off occasionally on wide left hand turns. Has never done it with new harness.

 

[Vsicks]

ok thanks guys I'll try what you guys advised me to do and see what happens. much appreciated feedback

 

[Vsicks]

All right guys figured what my problem was. The battery cable that connects to the starter was touching my down pipe so when I gave it gas it caused a short causing my car to lose power and boost. So there you have it. One more thing to check before buying a new 02 sensor, ignition module and coil pack. Thanks to all the guys who helped me out much appreciated.

 

[GNRick]

Glad you figured it out. Casper sells a positive battery cable which is longer than the stock one, to avoid touching the downpipe.

 

[Vsicks]

Thanks GNRick I’ll look into that.

 

[GNRick]

You're welcome. I bought both cables from Casper...positive and negative. A couple years later I bought his engine harness.