99 Tahoe no start, got fuel and spark

[chevy in my blood]

What is your fuel pressure? These engines don't like to fire on less than 50psi or so. Pull your plugs and check to see if they are wet with fuel. If they are, you have enough fuel pressure to fire the injectors, so that shouldn't be an issue. You'll need to clean them with some solvent and compressed air if they are fouled, or at least leave them to air dry for a bit. Good spark in the open air doesn't necessarily mean good spark under compression in the combustion chamber. I've seen more than a few of these engines with what appeared to be good spark that wouldn't start due to poor contacts and fouling on the cap and rotor. They are a known issue on these engines and should be changed if there is any doubt whatsoever. You wouldn't have spark at all if there was no rotor present in the distributor. Ignition timing could be way out if the distributor was pulled and put back in. You may need to roll the engine to TDC on cylinder 1 compression stroke and verify that the rotor is pointing toward cylinder 1 on the cap. That will put you in the ballpark, at least close enough to make an attempt to start. Lastly, if all else fails, check compression. It's possible that your engine's cam timing is off due to a slipped timing chain. It's not common, but possible.

I'm betting on low fuel pressure or an ignition issue, myself.

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Looks like you're right, so I need to apologize. I was frustrated. Plugs were great, timing is perfect, spark getting to plugs well. Finally said EFF it, and poured more than a tiny bit of gas in the TB and it busted right off 3 times. It's not getting any fuel. The filter is new. The pump is loud, but it could be that it doesn't have a ton of fuel in it. I'm going to get a pressure gauge and check the pressure and go from there. I'm happy I heard it run.

 

[df2x4]

I had a fuel pump go bad in my red truck that was incredibly loud, like you could hear it prime 100ft away from the truck if I hit my remote starter. Just wasn't delivering enough pressure.

 

[chevy in my blood]

Yeah, mine is pretty much that loud. I'm also wondering back to a passlock issue. Someone told me in a group that theirs did the same thing, and the security light didn't flash on theirs either, but he had to do a relearn on his to get it to start. I may try that tomorrow. Don't have much else I can do otherwise until pay day.

 

[chevy in my blood]

The only problem is it doesn't fire and then die, it doesn't try to fire at all. I figured if it was a passlock issue it would fire and then die instantly.

EDIT: I forgot to add that all I know about this truck before I got it was she drove it home from work one day and the next day it wouldn't start, and that when she first parked it it would fire and run with a steady supply of start fluid. Tags went out January 2017 I think, I'm sure it was parked a few months before that. It was well taken care of, regular oil changes and new plugs every few months, it has practically new NGKs in it, air filter, and fuel filter, etc. It doesn't throw any codes other than the fuel sending unit, I don't recall if it's high or now. I'm leaning toward weak pump, but I will inspect the regulator in the morning with my horoscope camera to see if it leaks or has been leaking

 

[chevy in my blood]

Been a busy couple days, thought I'd update, verified that the regulator is fine. Don't have a pressure gauge yet, hopefully will arrive tomorrow. But o was monkeying around with trying to make one and whole I was connecting it, I noticed after sitting 3 days the truck has pretty strong pressure still, so i think that says the regulator is fine. It also gives me the feeling my fuel pressure is okay, so it could be the passlock system. I haven't had time to do the relearn yet

 

[tom joyce]

I had a crank sensor go bad, and act like yours. There were no codes, and no test to check the sensor.
Is the fuel getting into the cylinder? Unplug the coil wire. Crank it over for a few seconds, then pull some plugs. They should be wet.
If the plugs are wet, then fuel is getting into the cylinder.
Dumping fuel in the TB bypasses the injectors. If the injector does not have power, it won't inject fuel - but you will still have pressure.
Test for 12 volts with key on, on one of the pink wires at the injector plug....If no voltage then it probably IS the passlock system.
By-passing the passlock is easy....

 

[chevy in my blood]

Tested fuel pressure, not getting any at all. Double checked I'm getting fuel to the gauge and tested another obs to make sure the gauge is working right. I'm getting fuel to the gauge, but not even managing to build even 1 psi. Pump is really loud too. I'm going to test pressure at the filter to make sure it isn't the problem, if I have the right fitting. Is it possible to accidentally swap the fuel line and the return at the pump? i had help when I put the tank in it the day I bought it. Otherwise the filter is backward (pulled it off and could blow through it like a brand new one might have put it back wrong) or the pump is trash. I would think it would make at least a pound of pressure since it is still working and definitely getting quite a bit of fuel to the gauge. Thoughts?

 

[RawbDidIt]

If the pump lines were backwards you'd see a negative pressure. Not sure if your particular gage shows negative pressure, but unless there's a peg, you'd see some movement in the wrong direction. Check the orientation of the filter. Three should be an arrow on it, and the outlet should be marked as well. My guess is your pump is shot. They aren't supposed to be loud. Test pressure behind the filter to diagnose pump failure.

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[chevy in my blood]

thanks or the reply, no my gauge does not have negative pressure and it has a peg. I only asked that because I've head it drain in the tank when the pump cycles on when I turn the key off. it doesn't do it all the time though. and the filter doesn't have an arrow but IIRC outlet was marked, which I put toward the engine, but I've had one person say "with absolute certainty" that that side should be toward the pump, so I'm second guessing it. If i unscrew the gauge from the hose gas pours out, i would think that it wouldn't be getting fuel at the rail at all if the lines were reversed. anyway, I'm going to test at the filter in the morning if i have the right fitting.

 

[chevy in my blood]

I only had about 30 minutes to mess with it the other night, I did not have the right fitting I rigged up something, it leaked but I did see more than 10 psi before It leaked down, so when I get a chance to get under it with a better jerry rigged gauge I will look again. its def. getting some kind of decent pressure to be able to spray out like a mist passed a hose clamp that I tightened with prejudice, but then again idk what kind of pressure that would take. still thinking the pump is on its last legs because of the noise, but I'm not gonna call it until I get a proper pressure reading.