Backfire 94 3/4t 454

[Clown 32]

Hello,

(I left work kind of pissed and stomped on it and it blew a hole in the muffler and now the truck is running sick)

Truck is backfiring when I let off of the peddle, just a pop not a bang. I noticed while the truck is running that my left injector is pouring the gas into the throttle body about 2X more than the right injector. I guess you could say I should just replace both injectors and see if it fixes the backfire and poor gas injection. I also noticed a intermitting rpm gauge, almost like the truck is missing, the gauge doesn't move smoothly. I still have great power and the truck idles fine. The truck temp has always ran about 210° or a tick higher.

What else can I check on this truck?
Should I do a full tune-up to track down the culprit?
Can I run a code check on a '94?
If I replace the injectors what else should I replace? O-rings? Gaskets? Reset the computer?
What does a backfire come from? Too much fuel? Timing off?

On a side note the truck has a 1" crack in the top of the radiator I just keep adding a little antifreeze ever so often, My father has a '93 suburban and he had the same kind of crack, it came down to a cracked head that was pumping up the cooling system enough to crack the radiator. I am not sure if mine has the same issue but we were told these engines were prone to cracking the heads and than getting an antifreeze leak.

sorry for the long post

Any help would be great.

181,000 miles

Thanks,

Kirk

[smaurno]

backfire means air and gas in the exhaust system. I had a 73 Impala that backfired so bad it blew off the muffler. I disabled the EGR and it never happened again. One injector dumping more gas than the other is not normal. I would correct what is obviously wrong first.

[Clown 32]

02-06-2009 08:29 PM
smaurno backfire means air and gas in the exhaust system. I had a 73 Impala that backfired so bad it blew off the muffler. I disabled the EGR and it never happened again. One injector dumping more gas than the other is not normal. I would correct what is obviously wrong first.

smauro,

Thanks for the reply.

How do I bypass the EGR Valve?

[Clown 32]

02-06-2009 08:29 PM
smaurno backfire means air and gas in the exhaust system. I had a 73 Impala that backfired so bad it blew off the muffler. I disabled the EGR and it never happened again. One injector dumping more gas than the other is not normal. I would correct what is obviously wrong first.

smauro,

Thanks for the reply.

How do I bypass the EGR Valve?