lsylvain

My 97 Chevy c3500 454 stalled out the other day and wouldn't restart. When trying to restart I get a nasty kickback. burnt out my old starter with it. Put on a new timing set, and crank sensor and new starter. Pulled the valve covers to see if there was anything visually wrong and re-torqued the rocker arms and everything looked ok. Cranked it once and it acted like it wanted to start, cranked it again and BAMM new starter in pieces on the floor. The timing chain has been checked and rechecked. I tested the fuel pressure I'm not 100% on the high pressure because my tester doesn't reach around to the cab so I couldn't read it but it showed around 55 psi in the time to jump out and look then it slowly drops down to 30 psi and hold, and I get 71 PSI with the return line clamped and it holds. I have my wife tomorrow so I'll be able to actually look at it. Could this kickback problem be the Fuel Pressure Regulator? Or do I perhaps have a more sinister valve problem? Or something else causing the kickback? I really don't want to go through another trial and error and kill another starter. The paper that came with the starter actually had a little blurb about this problem and says its either. Timing Chain, Crank Sensor, Pressure Regulator, Valve Adjustment, ECM, and a couple of other simple things.

I've asked several people at part stores etc and I get nothing but blank stares, so I figured I would give this a try. Oh and I'm also not pulling any codes with my code reader. And after I checked the fuel pressure I did seem to have a recolection of smelling gas right before it stalled out on the road it could just be my mind playing tricks on my though. Thanks for the help.

shamrock246

on mine 5.7 it was the crank sensor i would check the wiring going to it, when i did mine i replaced the connector also,after i replaced all that it worked about two weeks after that it started again that turned out to be a cheap cap and rotor put a AC/DELCO cap and rotor and its been fine since then,the fuel smell could be a leaking pressure regulator but i'm not up on the 454 injection setup

lsylvain

Thanks,

I replaced:

Fuel Pressure Reg
2 injectors that looked like they may be leaking a little
MAP Sensor
Cam Sensor
Crank Sensor
Rotor (The cap was $50.00 for the elcheopo guess I might try that next.)

I checked the fuel pressure before putting everything back together and it checkout OK.

Put it back together. Tried to crank it. Still has a little kickback and didn't start. Checked the Fuel pressure again. And it is dropping again. Crimped the return line and it still drops. I'm starting to think that something is triggering the injectors to open. I'm going to unplug the harness and do a test and see what I get. It seems like I'm loosing pressure faster than I was before I replaced everything. What a pain.

lsylvain

still no luck. I'm about to push it over into the river. Now I am only getting spark for the first cycle of the engine then nothing. I checked the coil and it tested out ok although on the low end, so I checked the module and it was bad so I replace that. I get good spark from the coil, but once it gets to the plug wires it only hits the 1 time. Does the computer somehow, shut down the spark though the distributor if it detects something wrong? At the coil it keeps on sparking as the engine is cranked. It could merely be a bad cap I replaced the rotor but another $50.00 hit on a guess is hard to swallow.

thanks for any input

Earthquake

Have you replaced the plug wires and plugs. If you are getting a good spark at the coil, but it's not at the plug could, be bad wires. Are all the wires like this or just one?

shamrock246

the advice i got from this forum was to use only AC/DLECO igniton parts.it turned out to be good advice my old rotor didn't have a plastic shield (blue in color)over the electrode going from the center to the tip and when the cap developed some very small cracks (you could barely see them) it would arc strait up and on that cap plays hell on the engine tryng to fire i got my stuff from summit racing ACDelco - Ignition Components - Ignitions & Electrical - C3500 - CHEVROLET - 1997 - SummitRacing.com

lsylvain

Plugs and wires have less than 2000 miles on them and look fine. Put a new cap on. too. Each plug will fire once then nothing. Like it gives up after each plug has fired. I fixed the fuel leak down. The "new" pressure regulator was bad. (Got to love pulling apart the intake twice.) Checked the timing chain just in case, that looked good. Went through and tapped on all the valves to see is any were stuck and also inspected the push rods, everything checked out there. Went through the firing order and checked to see if the rotor was at the right place for each cylinder in case somehow I got the timing 180 off that was all good.

All the rocker arms and lifters apear to be doing their jobs but it is hard to tell for sure since it isn't running. What about a worn out cam? If the valves aren't opening fully could it be that enough fuel isn't getting in and puddling up behind the valve, then when you stop cranking it drips in and floods it, then bam backfire, knock sensor picks it up and it shuts down the ignition signal. How would one check for something like that without a tear down?

thanks

lsylvain

Bump.. I had to step back for awhile on this truck, and now months later I actually have some time to try and figure this out. It can't be a fuel problem since everything is brand new at this point. It has to be something with the spark "shutting down" If I disconnect the coil wire and put my timing light on it and crank the engine it will keep flashing as long as a crank the engine. However, when the coil wire is connected I get 8 flashes then nothing, not 10 one time or 6 another. 8 flashes every time. It runs through one fireing sequence and stops. Why? What would shut it down like that. Every time I start to think of this thing it drives me nuts. A smarter man would take it in to a shop and let them figure it out, but I will not let this stupid thing out smart me. I will figure it out if im 100 years old.