Backfire thru carb problem on starbord engine------HELP
#21
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0F124358
Backfire through carb above 1200 rpm
454 MAG. BRAVO (GEN. V) GM 454 V-8 1992-1994 - 0D805069 THRU 0F304999
The serial number range can be either TB4 or TB5. In another thread OP said there is only 4 wires coming from the ICM which makes it a TB4
Timing should be 8* BTDC
Compression 130 to 145 psi
Swap carbs with no change
Edit: no knock sensor or module
Backfire through carb above 1200 rpm
454 MAG. BRAVO (GEN. V) GM 454 V-8 1992-1994 - 0D805069 THRU 0F304999
The serial number range can be either TB4 or TB5. In another thread OP said there is only 4 wires coming from the ICM which makes it a TB4
Timing should be 8* BTDC
Compression 130 to 145 psi
Swap carbs with no change
Edit: no knock sensor or module
Last edited by AllDodge; 05-22-2020 at 12:59 PM.
#23
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Nothing personel 353 (05-26-2020)
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#28
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I guess its time to switch distr. and module and see if its not a mechanical problem.
#29
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NEWEST UPDATE---- 5/25/20. swapped over a known good coil, still backfiring. Tried retarding the timing to 0 deg BTDC and even ATDC and still backfiring.
timed engine to 0 deg BTDC, marked the alignment of the #1 tower with the coil tower, spun engine over to 0 deg BTDC on the balancer, pulled the cap off and noticed that the rotor was not pointing towards the #1 tower but was actually about 20 degrees BTDC on #1. Swapped distributors and the engine ran fine and no backfiring. So now 1 of three possible solutions. A bad module, a bad pickup coil, or the rotor was not phased correctly. The module for this distributor is $400 and is obsolete and the pickup coil is another $50. At this point, I dont have ready access to the boat. and have told the guy that we can upgrade both distributors for a little more than the cost of replacing parts on just one distributor. I'm looking either at the DUI distributors (HEI) type distributor or the A-Team Performance (marine HEI ) distributor. I want to replace the whole distributor. Does anyone have personal preference of these two brands or another brand/system that is better?
timed engine to 0 deg BTDC, marked the alignment of the #1 tower with the coil tower, spun engine over to 0 deg BTDC on the balancer, pulled the cap off and noticed that the rotor was not pointing towards the #1 tower but was actually about 20 degrees BTDC on #1. Swapped distributors and the engine ran fine and no backfiring. So now 1 of three possible solutions. A bad module, a bad pickup coil, or the rotor was not phased correctly. The module for this distributor is $400 and is obsolete and the pickup coil is another $50. At this point, I dont have ready access to the boat. and have told the guy that we can upgrade both distributors for a little more than the cost of replacing parts on just one distributor. I'm looking either at the DUI distributors (HEI) type distributor or the A-Team Performance (marine HEI ) distributor. I want to replace the whole distributor. Does anyone have personal preference of these two brands or another brand/system that is better?
#30
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The A-Team is complete low cost Chyna right ? Compared to medium cost questionable Chy-na things.