stumbling engine

Only during moderate and excessive acceleration, my gst engine stumbles quite harshly. It sounds like it is just misfiring badly. I can distintly hear a popping sound, like a spark from the wires. I have done nearly everything the repair manual suggests: Fouled spark plugs, fuel injection system component faulty, fuel filter clogged, ignition system malfunctioning, and vacuum leak check. I swapped the plugs, wires, coils, and injectors with the gsx I have, as well as replaced the fuel filter with a new one. The gsx runs just fine with them. I do not have a gauge to test the vacuum lines though. Would they be a likely cause of this problem? What other factors could contribute to the popping noise?

It could have a boost leak causing it to backfire and that could be the popping sound you're hearing.

What plugs did you put in and what did you gap them at...

boost leak. Do a test

I had a friend of mine drive it around last night. He says he can hear an echo on some buildings of what sounds like a tiny exhaust leak. My car has a 3" exhaust so it didnt cross my mind that it was a little louder. He suggested I should do a compression test and fuel pressure test, just to make sure those are not contributing factors.

while you are doing those do a boost leak test, actually do that first because I can almost promise you its a boost leak.

A boost leak test is the easiest of those three the only probem is you need a compressor and not everyone has one

You can do it at a gas station or with a bike pump

i cant seem to find any instructions on how to do a boost leak test. I cant find any cracks or torn lines anywhere. It seems to be steadily getting worse on a daily basis.

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