96 Vortec 5.7 Crank but no start… help!!

[BlakeOlson]

So I fired my truck up one day it was running really bad and broke down on me like a block away acted like she was out of gas. I put gas in it later that day and fired it up and while still running like ****. It was dumping white smoke enough to fog up the block. Figured it was a head gasket or intake gasket but I checked my oil and water and both were fine. At that time I was able to get it to fire but couldn’t keep it running. Now when I hit they key it cranks and acts like it’s trying to fire but out of nowhere the motor locks up. Hard. Hard to explain how it can go from freely cranking to acting seized. For a few minutes after it “locks up” you hit the key and you hear the starter bang the flywheel. But it won’t crank over. Nothing will budge. You wait 10 to 15 minutes and hit the key and it’ll crank like crazy and suddenly lock up again. Worried about snapping the crank it stops that hard. It smells like raw fuel when it does crank. So is it dumping so much raw fuel into the cylinders that it’s hydro locking? Is my starter going bad? I’ve replaced the crank sensor by this time. Any help or insight would be appreciated thank you. Sorry for the long thread

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[Willy97chevy]

My 97 is doing the same exact thing bro and it's really I know for a fact that the wiring and how tight your starter is. I torqued the two starter bolts and gave the battery a good boost from my jumper and it fired right up. Now I just done a v6 vortec to v8 vortec swap and I'm still trying to do "ecm" upgrade bcuz it sounds like it's just falling off of 8 cylinders to maybe 7. New plugs, new wires, the real problem I think is I'm getting a confused look on the "97" in dash fuse box and the "99" under hood wiring fuse box and they both are pissed at each other.

 

[Willy97chevy]

I'm still getting no brake lights, no blower motor for heater, I have turn signals, running lights front and back headlights, but still no dash lights and when I do turn on the headlight switch my gauges go crazy and don't "set" where their normally supposed to. Can I be any more confusing?+)

 

[slovcan]

OP, the white smoke is a giveaway for coolant in the combustion chamber - blown head gasket. However, you said your oil and coolant are OK.

Your engine is definitely hydrolocking, but with what fluid? I'll go out on a short limb and say it is gas. Running rich will make black smoke, but running super rich to the point of not running will make white smoke - actually almost liquid gas coming out the tailpipe.

Check your oil level again. It should be well over full now. This will also mean it will have far less lubricating ability, so don't even bother trying to start it. Change the oil first.

So, either there is an electrical reason for dumping too much fuel into the cylinders or you have no spark or very bad spark. Plug it in to check for sensor codes. After the oil change check for spark (blue/white is good, yellow/orange is bad).

Hydrolocking can bend connecting rods. Don't keep trying to crank it.

 

[BlakeOlson]

I'm still getting no brake lights, no blower motor for heater, I have turn signals, running lights front and back headlights, but still no dash lights and when I do turn on the headlight switch my gauges go crazy and don't "set" where their normally supposed to. Can I be any more confusing?+

OP, the white smoke is a giveaway for coolant in the combustion chamber - blown head gasket. However, you said your oil and coolant are OK.

Your engine is definitely hydrolocking, but with what fluid? I'll go out on a short limb and say it is gas. Running rich will make black smoke, but running super rich to the point of not running will make white smoke - actually almost liquid gas coming out the tailpipe.

Check your oil level again. It should be well over full now. This will also mean it will have far less lubricating ability, so don't even bother trying to start it. Change the oil first.

So, either there is an electrical reason for dumping too much fuel into the cylinders or you have no spark or very bad spark. Plug it in to check for sensor codes. After the oil change check for spark (blue/white is good, yellow/orange is bad).

Hydrolocking can bend connecting rods. Don't keep trying to crank it.

Right on. I checked the oil it looks good. But I will change it. definitely gonna check for spark. So say it does have good spark. Do I go straight to replacing the spider injectors. Assuming they cracked and were blowing raw fuel with no restrictions. Or do I check timing chain. In case maybe it jumped time. She has 320k on it. She due for a rebuild. But if I can locate the source I might patch it until summer

 

[slovcan]

Plug it into an OBD2 bluetooth dongle and connect to an app like Torque on your phone to check fault codes FIRST.

I don't get why your oil level has not increased no matter what fluid caused the hydrolocks. The only place that could go is the crankcase. Maybe you were down a quart and now it's full? Does the oil smell like gas?

Jumping timing chains are not so common anymore. Even with high mileage it may be stretched, but I doubt it would jump. Stretched enough or jumped one tooth would affect starting and running. Two teeth might bend some valves.

Pull the plugs and see if any look washed. Those would indicate the affected cylinders.