Bogging/stalling out and the occasional backfire :)


New Member
Nov 13, 2015
87 grand national. Ran ok before installation of these parts.

Ngk ur5 sparkplugs
Msd plug wires
Gn1 performance:
3" downpipe w 46mm wastegate and boost controller
Extreme front mount intercooler
Cold air intake
Maf sensor (replaced before)
02 sensor
Simens 60lb injectors
Turbotweak chip made for my setup
2800-3000 non lock up stahl converter
B and m shift kit
Pypes 2.5" exhaust
I run premium gas

When it bogs and stahls the service engine light comes on and has randon but rare backfire. Since the gm stock waste gate was preset i was told i need to setup my boost controller and wastegate and my engine is being flooded with boost supposedly causing the stahling bogging. Also was told that i need different springs after switching to these parts. Any thoughts? Anyone set one of these wastegste boost controller setup from gn1? Im supposed to be running 18-19lbs of boost. Also i do have a scanmaster have not installed yet. I will soon.
Read the codes. Sounds like a bad coil module If it idles fine, but under any load the module is bad. Do you have a module and coil tester from caspers?
If your new MAF is a stock replacement part from a parts store, that's where I'll put my money. Need to jump out the ALDL connector and see if it's a MAF code, if so, that's ONE of your problems.

On the springs, if they are original then, yes, they need to be replaced yesterday.
The maf sensor was bought from gm dealer... i tried the ones from autozone etc and they didnt work the maf was working fine. So i think i can rule that one out but ill be installing the scan master after work and let yall know the codes. As far as i know they were stock injectors before i swapped them. As far as the springs go any reccomendations? I do not have the casper coil tester but i have been worried about it. The car sat for many years before i acquired it.
When working with these cars NEVER rule out something just because it's new. ESP a MAF.

I won't even touch a car with a stock MAF on it anymore. They're just too crappy to trust.

Without scantool numbers you're just shooting in the dark though. Pulling the code with a paper clip will get you a big clue.
If the injectors were stock it's important that the injector cups did not get left in the injector bores. I've seen it more than one were they were left in. They need to be removed. Pull the injectors back out and make sure these little cups are removed.


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Will get the codes for yall tomorrow. Scan master is now installed. Got saturday locked in to remove cups.
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Injector cups? Really? LMAO

cam sensor 180 out or coil pack module most likely

Make it easy, unplug the MAF and if it stops backfiring then its the maf as identified above