91 GSX pop's bad when accelerating(Video)

[z2roll4life7]

Hello, I have a slight problem, my 91 GSX will not accelerate. I kinda did a blind trade for this didn't really know what I was getting into. Any ways things I have checked: I did a boost leak test and found none thing, to my best ability I hooked up everything that was unplugged but there is a few phantom wires laying around. and the spark plugs are at .28(side note it looked like the car was running rich plugs were really sooty). Also this car looks to be modified a bit, I'm sure I have a GM maf, and the car is running a after market ignition, the fuel pump is a walbro 255(I am leaning towards this as my problem), and was told it has a ported 16g turbo. look at the video and you will see exactly what i'm taking about.(I tend to curse a lot so no small children should be present). Hopefully someone can point me in the next direction.

Thank You for your time

VID_20130527_191428_777.mp4 Video by z2roll4life7 | Photobucket

 

[BoostedK]

Plugs could be shot? Iv'e read that coil on plugs aren't the best either that could also be your problem. I dont think it would be the fuel pump though. Maybe switch back to regular wires.

 

[TwoGeezy]

I ran the coil on plug set up on my old eclipse and they caused me several problems. As BoostedK said, I'd try switching back to regular wires to see if that's the problem, and to save you a bit of trouble in the future.

 

[ChrisMgst]

When you did the boost leak test how much PSI did it hold?
It sounds like cylinder misfire. I would throughly look over the ignition system. Confirm no boost leaks, if problem still continue's maybe a bad injector.
I did notice your PCV system is wrong. Your bringing that bad air directly back into your intake.
http://www.dsmtuners.com/forums/articles-engine-fuel/366890-4g63t-pcv-system.html

I would also make sure the boost gauge is installed correctly.

 

[Alpha]

Sounds like boost leak, You may want to do a more thorough test.

It could also be too much fuel, I bet your injectors are bigger than the stock 450s. What are you tuning with?

 

[GSLENK]

I was getting ignition popping/breakup at high rpms. sounded like a pack of fire crackers going off. Power was lost during those events.

Colder plugs, and smaller gap solved the issue.

I also went ahead and did wires new ngk blues to be sure. Since you have COP, I suppose you could also try a colder range plug. I run br7es (not bpr7es) though either should work just fine. 20g turbo up to 25 psi no break up.

 

[Spanky_DSM]

Judging from the way your stock electric boost controller spikes and your barley even going it seems like a boost leak.

Even tho its total junk its based of your maf readings, so the higher it spikes the more air the maf has read, but obviously is escaping somewhere as your building no boost.

Get a boost gauge that reads vacuum.

 

[thomcasey]

Check all your vacuum hoses too. You should be holding -20-24hg at Idle. Looks like you are about 6-8, so a vacuum/boost leak is definitely present

 

[z2roll4life7]

Plugs could be shot? Iv'e read that coil on plugs aren't the best either that could also be your problem. I dont think it would be the fuel pump though. Maybe switch back to regular wires.

I have a Crane ignition I kinda don't want to lose it but if I have to I will go back to stock

I ran the coil on plug set up on my old eclipse and they caused me several problems. As BoostedK said, I'd try switching back to regular wires to see if that's the problem, and to save you a bit of trouble in the future.

See above

When you did the boost leak test how much PSI did it hold?
It sounds like cylinder misfire. I would throughly look over the ignition system. Confirm no boost leaks, if problem still continue's maybe a bad injector.
I did notice your PCV system is wrong. Your bringing that bad air directly back into your intake.
http://www.dsmtuners.com/forums/articles-engine-fuel/366890-4g63t-pcv-system.html

I would also make sure the boost gauge is installed correctly.

I will look over everything again and thanks for the link ill read it and see where I need to plumb the hoses. Also i wasn't able to verify how much pressure it made i will build a better leak tester with a gauge built in.

Sounds like boost leak, You may want to do a more thorough test.

It could also be too much fuel, I bet your injectors are bigger than the stock 450s. What are you tuning with?

The injectors are 550cc, at least that is what I was told. The plugs looked like it was running stupid rich and the ECU was a reflashed epromchip computer, with DSM link, at least that is what I was told. I will verify this.

I was getting ignition popping/breakup at high rpms. sounded like a pack of fire crackers going off. Power was lost during those events.

Colder plugs, and smaller gap solved the issue.

I also went ahead and did wires new ngk blues to be sure. Since you have COP, I suppose you could also try a colder range plug. I run br7es (not bpr7es) though either should work just fine. 20g turbo up to 25 psi no break up.

The car does have bpr7es and they are gapped to 0.28

Judging from the way your stock electric boost controller spikes and your barley even going it seems like a boost leak.

Even tho its total junk its based of your maf readings, so the higher it spikes the more air the maf has read, but obviously is escaping somewhere as your building no boost.

Get a boost gauge that reads vacuum.

You learn something everyday. I just ordered a different boost gauge that show's vacuum.

Check all your vacuum hoses too. You should be holding -20-24hg at Idle. Looks like you are about 6-8, so a vacuum/boost leak is definitely present

I will Build another and better leak tester one with a gauge to measure pressure




I will report back with everything I have done in a day or two, one thing I did notice is the car will shut off if the maf is unplugged.

Thanks again for all the advice.

 

[z2roll4life7]

Well I am a idiot. I re-did the boost leak test and found I was holding ZERO Pressure. So I went Thru EVERYTHING and found none thing. I was lost, puzzled and pissed. Then I stumbled on this little problem...

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I will report back once I get it re-welded and put back on the car.

 

[z2roll4life7]

Well that did the trick. She runs up till redline but she still has an idle surge, only when she is cold though. Also the car pulls nice at 17lbs! I'm pretty stoked considering what I traded to get this car, I came out on top big time.