Warm Start Problems

[j91z28d1]

other thou I had was hold the peddle to the floor to clear flood before cranking.. then crank till you get good fuel pressure and then release the peddle

 

[mcsc1]

What about a snap-on scanner? That’s the only one I have access to.

Originally put in a Delphi pump and now the warrantied Delphi is a carquest. Fuel pressures are fine with key on engine off and also when running. After it bled down though to 16-18 psi and then turned key on it would only reach 24-26 psi after engine had been on and “primed”.

 

[mcsc1]

other thou I had was hold the peddle to the floor to clear flood before cranking.. then crank till you get good fuel pressure and then release the peddle

Yep that’s my dilemma. It acts like it’s flooded and it does lose pressure but everything I’ve done and looked at doesn’t show me where. I have a possible injector I want to warranty as all my plugs smelled like burnt fuel except one. That one smelled like raw gas.

 

[j91z28d1]

Yep that’s my dilemma. It acts like it’s flooded and it does lose pressure but everything I’ve done and looked at doesn’t show me where. I have a possible injector I want to warranty as all my plugs smelled like burnt fuel except one. That one smelled like raw gas.

you could try unplugging that injector. it will fire on 7. but also even if one of the 7 is rich should still start. might not be the smoothest thing but I'd think it would fire. there's a guy here that disconnect 2 injectors and 2 rockers I think it was and driving on 6 cyl because of a afm fault.

 

[mcsc1]

you could try unplugging that injector. it will fire on 7. but also even if one of the 7 is rich should still start. might not be the smoothest thing but I'd think it would fire. there's a guy here that disconnect 2 injectors and 2 rockers I think it was and driving on 6 cyl because of a afm fault.

I may try that to see if it’s my issue but definitely not driving on that.

 

[Doubeleive]

you could try unplugging that injector. it will fire on 7. but also even if one of the 7 is rich should still start. might not be the smoothest thing but I'd think it would fire. there's a guy here that disconnect 2 injectors and 2 rockers I think it was and driving on 6 cyl because of a afm fault.

ya that's a method to easily detect a misfire or other isssue's by pulling the coil harness off one by one until you no longer "hear' a difference

 

[j91z28d1]

I may try that to see if it’s my issue but definitely not driving on that.

definitely don't drive on it.. just crank and start.

since you have a scanner, if you can watch that and either cycle the key a few times or just clear flood till you have psi, and then let it crank. see what that does. I have a feeling your low pressure is throwing the whole crank routine off. I base that on nothing but a guess lol. they do sell check valves for fuel systems. normally only used for big aftermarket fuel systems using 2 or more pumps. but as far as I understand it, the pump should have a check valve in it.

the one that doesn't hold at work was from napa. we try to use oem these days.

if getting the pressure up first works, you might just have to go with a new oem from the dealer or gm parts direct. I don't trust Amazon and I kinda questioned some acdelco plug wires from Rock auto recently, they looked the same, but the oem I took off had a part number on the wire, these didn't. after getting burnt by Amazon acdelco parts twice now. I'm always worried if they are legit.

 

[mcsc1]

definitely don't drive on it.. just crank and start.

since you have a scanner, if you can watch that and either cycle the key a few times or just clear flood till you have psi, and then let it crank. see what that does. I have a feeling your low pressure is throwing the whole crank routine off. I base that on nothing but a guess lol. they do sell check valves for fuel systems. normally only used for big aftermarket fuel systems using 2 or more pumps. but as far as I understand it, the pump should have a check valve in it.

the one that doesn't hold at work was from napa. we try to use oem these days.

if getting the pressure up first works, you might just have to go with a new oem from the dealer or gm parts direct. I don't trust Amazon and I kinda questioned some acdelco plug wires from Rock auto recently, they looked the same, but the oem I took off had a part number on the wire, these didn't. after getting burnt by Amazon acdelco parts twice now. I'm always worried if they are legit.

My pressure is great at cold start, running, etc. but it falls short only after it’s warm and bled down. I do agree though, it’s an issue I thought was solved by replacing the pump. Would anything else be keeping it from building pressure?

 

[OR VietVet]

Thanks for all the suggestions. I too have thought control module but having it programmed to the vin doesn’t sound fun or cheap.

One spark plug smelled like raw fuel where the others all smelled like burnt fuel. So that could be my issue.

We’ve tried checking grounds in the engine bay and cleaned everything up a little. But nothing changed after doing that.

I had thought cam position sensor, but I hate just throwing parts. I’m unable to leave it for more than a day due to needing it for work.

I hate you are having this problem but you just said something funny to me. You just said, "I hate throwing parts", but you initial post lists a bunch of parts. Sometimes these rigs just drain the wallet.

 

[mcsc1]

Unplugged the injector I suspected of leaking and it starts much better. Runs like poop but it doesn’t crank for almost a full cycle like it does normally.