Car pops in intake and cut off after 15 psi of boost

gn_steve

boosted canadian
Joined
Apr 12, 2011
Hi guys and gals i have my 1987 gn that i just replaced all the springs on it and at the same time i instaled a brand new razor alky kit!

Well know car runs awesome until i reach 15 psi of boost then it cut off and back fires and pops in the intake

This is what i did up to know
Unpluged cam sensor. Not that
Unpluged maf. Not that
Checked fuel pressure. Not that
Checked all vacum lines. Not that

What else???


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What chip are you using? did you upgrade it to an alky chip? sure you got good methanol? is the turn on light turning red then green when the sputtering starts? a few more details on your setup. New alky user here as well, got my 5.7 TT alky chip and all is good here. what setting you starting out on with the controller.
 
Are the plugs non resistor core plugs? If so they have been known to cause problems with ecm

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Right now i have a turbo tweak chip for 60 pound injectors but no alky but i turned off the alky and still does it my alcool is torco alcool ! My plugs are autolite 104's and my heads are gn1 aluminium heads!


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Hi guys and gals i have my 1987 gn that i just replaced all the springs on it and at the same time i instaled a brand new razor alky kit!

Well know car runs awesome until i reach 15 psi of boost then it cut off and back fires and pops in the intake

This is what i did up to know
Unpluged cam sensor. Not that
Unpluged maf. Not that
Checked fuel pressure. Not that
Checked all vacum lines. Not that

What else???


Sent from my iPhone using Tapatalk

Check plug gap, check coil pack/ ignition module.. What maf?
 
you will probably want to keep of the gas pedal until you figure it out. I never did a spring replacement, but maybe someone that has can tell you the symptoms of not having something right or not hooking something up correctly after the install. All the vacuum lines get put back proper ? no leaks?
 
you will probably want to keep of the gas pedal until you figure it out. I never did a spring replacement, but maybe someone that has can tell you the symptoms of not having something right or not hooking something up correctly after the install. All the vacuum lines get put back proper ? no leaks?
Yes this is not the first time doing this job all vacum line are brand new i put silicone vacum lines ! I am realy stumped!


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Plug gap is 25 stock coil stock ignition module and stock maf


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Try a known good coil pack, ignition module, maf .. Those are the big 3 that cause this symptom other than a bad fuel pump
 
Do you have a scanmaster by chance. did your MAF values go up to 225 or full scale at wot. with the backfiring, you probably got off it before that but you should be able to at least see it rising if good. also. did you get the alky kit with the 3 bar or still running the 2 bar map sensor
 
Do you have a scanmaster by chance. did your MAF values go up to 225 or full scale at wot. with the backfiring, you probably got off it before that but you should be able to at least see it rising if good. also. did you get the alky kit with the 3 bar or still running the 2 bar map sensor
Got out of it as soon as it poped and i got the kit with the 3 bar map!


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If this is something that was not happening before, I would check over the work that was just done.
 
Check for a cracked insulator on your plugs. I had similar symptom as yours and it took me weeks to find that it was a cracked spark plug.
 
Well guys found the problem it was my ignition module that took a crap replaced it with a good one and car runs like a champ!!!

Thanks for all your input guys it is very apreciated!


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Glad you got it going good again! I'd still lose that stock maf cause it's gonna cause you problems.
 
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