5.0 backfires - problem solved!

[bucketobolts]

A lean engine does tend to run hotter than a rich. But a lean engine will burn all the fuel in the chamber and tend to "look" for fuel in intake.

On the other hand a rich condition has excess fuel exiting the chamber and igniting in the exhaust.

When you follow the flame travel from combustion, lean travels toward the intake burning he intake valve, and rich travels down the exhaust.

[SC74]

UPDATE...

The motor is running much better now. We never put a timing pointer on it when we dressed the front-end because I swapped to explorer pieces I bought here and there and never even thought about missing the pointer. Keith robbed a pointer for me from a local pick-n-pull and cleaned / painted it up for me. We were in such a mad dash to get the rig to last year's Charlotte event that we only timed it by ear with open headers so it would drive itself on and off of the trailer.

I ended up having to remove the entire pass. side explorer bracket to get access to the lower front cover bolts to install the pointer, but got it on and back together. I was running several degrees retarded. After remembering to unplug the spout I got it timed and it is running MUCH better now. No backfiring so far and smoother idle. I will probably pull it out in the yard tomorrow to give it a load and see what it does.

Oh yea... no more glowing cherry red headers either! I didn't let it run long in the garage today but hope to check it out more tomorrow.

[blazinchuck]

good deal Robert...glad yall made some progress

[SC74]

went to pull it out in the yard today and it is running worse than before???? :banghead:

Checked the timing and it's dead on where I set it yesterday and it ran so well.

Checked codes and there is one code in the CM that I have never seen - 95 - Fuel pump secondary circuit failure. The EEC senses infinite resistance to ground from the fuel pump on the Fuel Pump Monitor circuit. cratchhe:

[SC74]

It's definitely a fuel pressure issue. When I feel the HP fuel line it is not consistent at all and purges pressure on/off. I just can't understand why it ran so well yesterday and craps out on me today. I am going to meter my connections at the pump to see if it is a power to pump problem or pump problem.

[bucketobolts]

What pump are you running?

[SC74]

Aaron - I am running a MSD pump from Summit..

I found the problem today! It ran great in the garage but as soon as I pulled it out and first bump I hit it went to running rough and backfiring.

I cracked the fuel cell filler to make sure it wasn't a vent problem - problem continued.

I checked voltage to the pump - steady 13.54 volts but the pump was loud and very inconsistent.

It was either a pump or something restricting fuel before the pump. I have a filter and a LP pump priming the HP pump.

Before bypassing the LP pump I pulled the pre-pump filter and took the brass looking insert out. Screwed the housing back together and WAAALAAAA!!! IT RUNS!!!

I have had problems with this same filter before and will replace it with a better filter. I do have another filter after the HP pump also.

[JayT]

Woot! Congrats!

[blazinchuck]

thats great! but any idea why you would be getting that code?

[SC74]

no clue about that code. I did swap my relay out for a radio shack brand so who knows if it's any better than what I had in there. It is running much better than it ever has now.