Can't get truck to start

[David97k1500]

Ok so I have a 1997 k1500 with the 5.7 and I cut the cats out because they were clogged and it started to back fire really bad and then one day it just stopped running and wouldn't fire so I put a new full pump in and still nothing turns out it was an egr fuse that was blown so I put a new one in and it kept blowing the 25s so I put a 30 in and it started right up and ran for a little then shut off again I think because it was to rich because of the o2 sensors so I put resistors on the downstream ones and it ran great was driving it home and it just died and wouldn't restart the fuse isn't blown or anything I'm at the limit of what I can think of and was seeing if anyone else knew thanks

 

[michael hurd]

What diagnosis have you done?

Are there any codes pending or stored in the PCM?

 

[David97k1500]

I tryed to check and it's not able to do I'm thinking the computer is bad

 

[Biggershaft96]

Check your ground wires.

 

[David97k1500]

I was just messing with it and it looks like something on the ignition module shorted

 

[michael hurd]

If you have no communication to the PCM, check your lighter socket fuse, they are on the same circuit. If the fuse is dead, replace it and try again to communicate to the PCM.

When did you last replace the cap and rotor? If unknown, carefully inspect the inside of the cap and assess the rotor button and tip condition, if in doubt, replace.

Plugs? If iridium, can last up to 100,000 miles, however I would change them out long before that mark. Note 'can' last and 'will' last are two separate meanings. If you have nil for sealing around the valve stem seals and low compression to boot, they could be fouled with deposits in a few thousand miles.

Did you also replace the fuel filter at the same time the pump was changed? Did you verify you have good voltage at the pump electrical connector?

If you have correct timing, spark and fuel it has no choice but to run.

Tossing parts at it without diagnosis can get expensive quickly.

 

[Ironhead]

Like all big problems, this one can be broken down into small, easy-to-digest problems.

Spark: Plugs, rotor, cap, all easy to check, and no need to buy new ones unless there's a problem with the old ones.

Fuel: Does the fuel pump turn on (hum) when the key is turned? There's a fuel pump relay under the hood, clearly marked. Next, as Michael Hurd suggested, check the filter.

Fuses: Easy to pull them, one at a time, and check them, and the holders for continuity and corrosion.

Timing: If you haven't moved the distributor, it should be fine. You can gently try to turn the distributor to make sure the clamping bolt is tight. If the body of the distributor moves, you will have to time the engine.

If none of these simple checks get the engine started, I would do whatever it takes to pull the codes off the OBD port.

 

[David97k1500]

I did the entire full pump because it wasn't turning on and after that I tried to start it and it still wouldn't start so I looked at the fuses and I think it is called the egr fuse sound I put a new one in and it started and idled fine put it in drive and it kept blowing so I went up to a 30 and it would back fire like crazy So I put o2 resistors on the downstream and it drove like normal acuttaly the best it ever has and then it just shut off and wouldn't restart I haven't checked the distributor or any of the ignition stuff yet I couldn't get to it today but I think I'm just going to go ahead and replace it all because whoever owned the truck before me just ran it into the ground