Crank-No Start 99 Tahoe 4x4 5.7

no cigar · Apr 16, 2024

I'm having an intermittent crank-no start on my truck. This seemed to develop over time when the truck would crank slowly almost as if the battery was dead. One evening the truck died for good and couldn't be jumped so in went a new battery. This did not solve the problem. A few days later the truck starts up just fine. It has been this way now for over a year (I have a truck I drive regularly) and I'm not sure what it could be. When it enters this phase, it will last a couple of days.

When I try to start, it will try to run but it will sound as though the engine siezed and the starter has disengaged. I have youtube videos of this below.

Could this be passlock? I have noticed there is a draw on the battery from time to time.

no cigar · Apr 16, 2024

Would also add that there is an odor of gasoline and also occasionally some smoke that will come from somewhere under the hood.

strutaeng · Apr 16, 2024

It's either the fuel pressure regulator leaking fuel into the engine (flooding the engine) and/or leaking injector (same effect but to affecting cylinder(s).

Hook up a fuel pressure gauge and report back:
A. Key on, engine off: pressure?
B. Same as above after 5, 15 minutes?
C. Engine running: pressure?

Note that flooding the engine with fuel can cause a hydrolock condition, which can result in catastrophic damage such as bent rods (engine is trying to compress a liquid, which is not compressible.)

I mention that because of your description of difficult cranking. May be related, or may be another issue altogether.

Proceed with caution...

Edit: did not watch the video, will try to later.

exp500 · Apr 16, 2024

Another test to help point in a direction for Cure- Steady state fuel trims at a couple different speeds 35/45/55/65.
Another test is cycle key to run, off/ run,off/ for a few seconds on run. Then try to start. Post up your results of all your tests, and we will post up our combined knowledge of possibles,

east302 · Apr 16, 2024

no cigar said:
Could this be passlock? I have noticed there is a draw on the battery from time to time.

Passlock will usually let it start and run for a second before it kills the injectors. Your video doesn’t really fit that.

exp500 · Apr 26, 2024

Any Fix Yet? Or any further testing?
I should have mentioned, any miss or no start the first thing to test is Distributor cap / Spark test.

no cigar · Apr 26, 2024

I tried again. Will have to get it towed home as it’s sitting on the street at my gf house.

Still same issues. Cranks, then tries to go only to stutter and buck real hard before the starter seems to lose engagement and spin freely (as in the first video). Does shudder roughly a few times as though it wants to run but just doesn’t.

no cigar · Apr 26, 2024

Also, I didn’t think fuel injected engines could flood.

The truck had a new style spider for about 5-6 years that worked fine. During a maintenance stay at a shop last year that unit was replaced. I assume a new fuel pressure regulator would have come with the new unit?

strutaeng · Apr 26, 2024

no cigar said:
Also, I didn’t think fuel injected engines could flood.

The truck had a new style spider for about 5-6 years that worked fine. During a maintenance stay at a shop last year that unit was replaced. I assume a new fuel pressure regulator would have come with the new unit?

Unfortunately, they can flood. Not common, but does happen. I saw the first video and it may be that that "loss of starter engagement" IS loss of compression. Basically, the sound is different because when the starter is trying to compress that cylinder, it just free-wheels... Was the truck running good before?

Before trying to start it again, spin it over by hand with a long breaker bar. You know if one cylinder has lost compression. Then remove the spark plugs and see if any cylinder has fuel in it.

Fuel pressure regulator can leak, and you won't know because it's inside the plenum. You can remove the intake tube and shine with a flashlight as well. Have a helper prime the fuel system with key on run position.

exp500 · Saturday at 4:48 PM

no cigar said:
Also, I didn’t think fuel injected engines could flood.

The truck had a new style spider for about 5-6 years that worked fine. During a maintenance stay at a shop last year that unit was replaced. I assume a new fuel pressure regulator would have come with the new unit?

Throttle floored will stop fuel flow on startup if needed. Do you have a scanner at all? Any Codes?

Crank-No Start 99 Tahoe 4x4 5.7

no cigar

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