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what could this be?

Old Mar 13, 2004 | 09:05 PM
  #1  
quickL98's Avatar
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From: helldon, fl
Car: 87 trans am GTA
Engine: tesla permanent magnet
Transmission: 93 T-56
Axle/Gears: moser 12bolt w/ 3.73
what could this be?

my car "pops" from the exhuast at low rpms and has a significant loss in power, my timing is set(6 deg. base) as is my fuel pressure( 46#'s)

my headers will glow ,mainly the 3,5 and 4,6 tubes being the most noticable

could this be burnt valves?

total timing at 3k rpm's in N is 39deg's and the f/p holds steady.
my heads are AFR L98 190's and the motor really doesnt have a many miles just a few thousand i really dont know what else it could be? or really what else to check.
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Old Mar 13, 2004 | 09:14 PM
  #2  
dankhound's Avatar
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From: Bloomingdale,IL
Car: 91 RS
Engine: 305 Tbi (L03)
Transmission: 700r4
Those cylinders could be running lean but itd have to be lean enuf to cause a mistfire. One thing to double check is the plug wires arent crossed or crossing. Plug wires that cross each other can fire on the wrong cylinder.
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Old Mar 14, 2004 | 06:08 AM
  #3  
RB83L69's Avatar
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From: Loveland, OH, US
Car: 4
Engine: 6
Transmission: 5
3,5 and 4,6
Do you notice the pattern?

It's the 2 center cylinders on each side.... the favorite place for head gaskets to blow. Most often, as a result of over-torquing, or occasionally just general failure, especially if they're steel shim stock gaskets. But with it being both sides, I'd suspect over-torquing.

I'd suggest a compression check.
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Old Mar 14, 2004 | 12:14 PM
  #4  
quickL98's Avatar
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From: helldon, fl
Car: 87 trans am GTA
Engine: tesla permanent magnet
Transmission: 93 T-56
Axle/Gears: moser 12bolt w/ 3.73
the heads are torqued correctly and the head gaskets are felpro blue with stainless fire ring and have the enlarged coolant hole btween 3,5 and 4,6 that require drilling out the blocks existing small hole .
i wouldnt suspect it to be a gasket failure

to be honest everything was fine until got my chip back and replaqced my MAF
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