car popping

[JRGN]

got a ?, hoping someone can help, I have a few friends that own GNs and all seem to have the same problem, the car pops out the exhaust when getting on it, have checked the cam sensor,coil pack and module, wires, plugs and everything else we can think of, the only other thing is that the cars have is the V-4 intercooler and they seem to do this when the outside temps are below 40 deg but when it is warmer outside the cars don't seem to do this. any help would be appreciated. Thanks Jr.

[GrndNatnl]

Sounds like fueling to me. Big intercooler, cold temps, making intake charge denser, altering the air/fuel ratio. Have these guys toyed with the fuel pressure? What chips? What turbos? What injectors? What kind of knock retard?

[kenny]

Do the cars have a translater?

[HairDrier]

Yeah you guys are all lean. What do your BLM's and INT's look like? Turn the FP up to 46-47psi and see what happens

[JRGN]

Do the cars have a translater? Kenny none of the cars have a translater, stock maf.

[JRGN]

Yeah you guys are all lean. What do your BLM's and INT's look like? Turn the FP up to 46-47psi and see what happensBob the scanmaster is reading 770 to 840 on the o2s, one on the cars has a 61,v-4,009s,and champion irons,this seems to happen alsoat low boost like 14-15 lbs. Thanks for the help anything else comes to mind will take a look at the blm's and int's. Jr.

[HairDrier]

Those are the O2's at WOT or part throttle? Part throttle is what we are concerned with.

Crank the FP up, and if it stops popping that means you have a fuel issue, either in the chip's part throttle fuel map or somewhere else.

If the popping continues with the additional fuel, then you probably have a ignition problem. Your ignition system may be marginal and the increased air density is causing it to not be up to the task
Get those BLM and INT numbers at the rpm where it is popping!

[whitettype86]

What plugs are u using and what are u guys gapping the plugs too :fragez:

[COLD AIR]

MAF ? Last times out I was getting some backfire,then would die at idle,just put in DFI car idles fine(still need to program)

[ineil]

I have been havng some popping when I get to about 10 pai boost. The only thing I have added are a set of NGK IRIDIUM IX SPARK PLUGS, and new Megnacore 10mm plug wires. Could it be the plugs?

[STP]

Doesn't sound like plugs to me if it doesn't pop above 15psi..More likely to blow the spark out at higher boost levels not lower. Sounds like fueling in the chip to me. I don't know anything about the Iridiums, as I've always run NGK UR5's or TR5's depending on which car. Both gapped at .032. What kind of pumps are you running? You aren't turning on a second pump with a hobbs switch are you? Nothing wrong with doing it that way, but if you're turning on a pump at 10psi with a hobbs switch the car may be fat, until it starts making power via higher boost levels..Just some ideas. Any of the cars running alky? HTH

[ineil]

I have been running the same Testa custom chip for over a year with no problem. BTW, I just piggybacked off of the other older thread. The car was running great for a long time. I have moved the battery to the trunk recently, and other then that the plugs and the wires is all I have done. The fuel reg is Walbro 340, and hot-wired. Everything is up to par. It pops on anything over 10psi, so I do not try to go any higher. The new battery cable is routed out of the way of any high heat and is wrapped in high heat shield.

I found this out the hard way, when a convoy of Mustang Cobras passed me on their way back from a car show. I wanted to embarrass them, but soon found I was the one embarrassed

[Nick Micale]

......... Could it be the plugs?

YES! :fragez:

[Vacuum 6]

I have been running the same Testa custom chip for over a year with no problem. BTW, I just piggybacked off of the other older thread. The car was running great for a long time. I have moved the battery to the trunk recently, and other then that the plugs and the wires is all I have done. The fuel reg is Walbro 340, and hot-wired. Everything is up to par. It pops on anything over 10psi, so I do not try to go any higher. The new battery cable is routed out of the way of any high heat and is wrapped in high heat shield.

I found this out the hard way, when a convoy of Mustang Cobras passed me on their way back from a car show. I wanted to embarrass them, but soon found I was the one embarrassed

Might want to check your coil pack and/or module.

[STP]

I say plugs or a voltage problem..Verify you are getting at ~14v or more wide open throttle.

[Aztlanahauc]

Mine pops at 15 pounds.....I just put in some AC Delco 43s gapped at 35...maybe I need to change them... :fragez: I have a mostly stock set up, only mods are a stock location K&N, exhaust and a chip of unknown orgin. At first I though maybe by DS header being cracked had something to do with it.

What would you all recommend for plugs and at what gap?

[2QUICK2B6]

My dads 87GN had like a missfire and would stumble @ low rpm. We changed just about everything. checked the camsensor and it was out of adjustment. car runs like a 13k mile car should now

[Turbo Archie]

cam senser or ground

[TURBOTWISTER]

DITTO THAT! SOUNDS LIKE POSSIBLY THE CAM SENSOR TO ME ALSO!It may be bad or it may be out of adjustment."while the engine is running" unplug the cam sensor.this will put the injectors into batch fire mode and turn on the sevice engine soon light but it will run much better if the cam sensor is indeed your problem.


Nick,

[1FASTV6]

Did you change out the plugs yet?