Or so I assume that's what's happening. If I crank the car in the morning it fires right up, idles, then dies after roughly a minute or so. Just completely shuts off and I can't crank it up at all. If I give it a few hours, it will crank right back up, only to die after a minute or two again.

Backstory, I washed the engine bay last weekend, thought I didn't wet anything important but who knows. Problem didn't exist before that though. I also took an air compressor and blew any excess water off. I don't daily drive it though so I thought maybe something was still wet and needed to dry. I've checked all connections and MAF, everything is dry. When it does it's shut off, it seems like it has no fuel pressure in the lines. I don't have a tester but if I press the shrader valve nothing comes out. But when I let it cool and it cranks, there is fuel pressure.

Also, I hooked up a code scanner and it showed a P0335 crankshaft position sensor code. Could I have gotten that wet and it just wont dry? It just doesn't make sense that it only cranks and idles cold until it's apparently going in to closed loop before dying and wont' crank again until it's cold again.
Thanks!

 

When was the fuel filter last changed?

According to the factory service manual, P0335 can be caused by "running out of fuel".

Definitely need to check the fuel pressure.

 

I hadn't even considered that. It's been a while, and was on my list of to do's on this project car. I'd tuned it up recently with fresh plugs and wires, oil, air filter, but haven't changed that yet. I'll pick one up on the way home. Thanks for your response! I'll pick up a pressure tester too and post results later.

 

One more question @Injuneer what do you think causes it to be able to crank again when cooled off if it's fuel related? I'm just curious how that happens. Thanks!

 

I've seen this happen with another car of mine many years ago. As the car sits not running, fuel seeps through the dirty filter, relieving the pressure between the pump and the filter, and fills the system. When the engine starts, it uses up the fuel in the system, plus any new fuel that is seeping slowly through the filter. But eventually it has used up the fuel in the system and the small amount seeping through the filter isn’t enough to keep the engine running.

Just guessing that may be the problem here. But discovering that lack of fuel could set the crank sensor code (I wouldn’t have thought of that without seeing in the manual) made it a more probable cause. The fact you get nothing out of the Schrader valve would seem to reinforce that.

Keep in mind, I have never owned an LS1, but I am aware of the differences between the two engines, and their fuel systems. But it’s easier for me to work through LT1 problems. Unfortunately, most of rhe people that come to this site any more are LT1 owners.

 

That definitely makes sense. Well, unfortunately that didn't fix it. I put a new filter in, it appeared to be the original AC Delco so I was confident this would be it. So when I use the fuel pressure tester with the key in on position but engine not cranked, it hit's about 30 then slowly goes down to zero. Is that normal? I couldn't get a reading while it was running and before the car died. I'll try again later, it will almost certainly crank back up in a few hours which is what it keeps doing.

 

The LS1 fuel system runs at 58 PSI. It is a dead end system (regulator is back by the tank, no return line). There is no vacuum compensation, so the pressure should always be 58 PSI.

I don’t know what the pressure typically reaches when the pump primes, but logically it should get close to 58 PSI. Start it, watching the pressure. and keep watching it until the engine shuts itself down. If the pressure falls off, it’s the pump, the pressure regulator, or a leak.

 

Thanks. Yeah I was going to ask if there was any vacuum line with the fuel system. Well, when I can crank it it gets 58 psi and starts to drop really fast. Like within 30 seconds to a minute at most it's gone and the car dies. What keeps baffling me though is I can't for the life of me start it again until sometimes the next day. It's like once it dies it takes 6+ hours to work again. And then it repeats the exact same problem. When it does die, I can turn the key to the on position and still get up to 50+ psi but it wont crank at all and the PSI drops back to zero after maybe 10 seconds.

I don't see or smell any fuel leaking from the engine bay, and checked underneath the car and don't see any leaks. I'm guessing fuel pump/pressure regulater.

Thanks.

 

Then we have to dig deeper into the crank position sensor code.

I don't think the problem is in switching fron open to closed loop. Typically it can’t go into closed loop until the O2 sensors are hot enough to work (~600°F), the coolant is partially warmed up (120-140°), and a timer from cold start times out (over 3 minutes on the LT1). LS1 may be different.

 

You might try changing your fuel pump relay. It could be going bad and simply quit working. I had that happen on my 00Z28.

 

So do you still think the fuel pump might be going as well since it loses pressure? Or is that possibly something related to the P0335 code? Thanks.

 

I tried checking that by swapping one of the other relays and it still did it unfortunately.

 

I need to look at the factory service manual for the P0335 code description. The engine may not run depending on the failure mode.

 

Thank you for your help. I plan to get back under the car this morning and check the wiring to the sensor and sensor itself.

 

Well it seems to have been the sensor. Bought one this morning and put it in, it fired right up, and held 58 PSI a solid 10 minutes of it idling. Drove fine as well. Thanks for your help!