5.9 v8 is going be the death of me

[MagSport]

ill try another throttle possition sensor today, then is there any way to "test" injectors?

Quick search yielded this:

If an injector is stuck open or closed, I would also imagine the voltage would be steady instead of alternating.

 

[suede]

thats easy to check if you have a vehicle that will run....

 

[dapepper9]

ill try another throttle possition sensor today, then is there any way to "test" injectors?

Ohm check for 11-14ohms and using a spare battery touch a wire to each prong to "fire" it

 

[suede]

awesome! thanks

 

[suede]

they all ohmed out fine, took them off, found out there is a place in town that can hook them up and test them individually.... so we will find out tomorrow

 

[suede]

injectors were cleaned, new orings, flow tested, new baskets, etc. put back in, still no dice.... tried a engine coolant temp sensor, as someone had suggested that it may be leaving it in closed loop dumping fuel in but that didnt help either..... im really at a loss with this one...

if its left alone a few days and you try it, it has the roughest idle ever for about 10 seconds then its flooded out and wont run at all, what else would cause injectors to spray too much fuel?

 

[auskip07]

Try to start it with the pre cat 02 sensor unscrewed. Easy test to see if your cat is clogged and choking the engine.

 

[Rustycowl69]

injectors were cleaned, new orings, flow tested, new baskets, etc. put back in, still no dice.... tried a engine coolant temp sensor, as someone had suggested that it may be leaving it in closed loop dumping fuel in but that didnt help either..... im really at a loss with this one...

if its left alone a few days and you try it, it has the roughest idle ever for about 10 seconds then its flooded out and wont run at all, what else would cause injectors to spray too much fuel?

I don't know about your Gen fuel injection, but in the 1st Gen tb injection was ground sensitive. I made the mistake of not hooking up one of the engine grounds, and the injectors went full rich, and about drown that 318.

 

[joepizuro]

The computer richens on cold starts and during cold weather. Also depends on what sensors are working which mode it starts in. It also gets a multiplier for cranking. I was looking through the ecu last night. I'm guessing it's not your problem tho. Just disconnect battery for a while and if that don't work it isn't computer related. Also unplug the o2 from its harness and see if it starts. I been following your posts but your always a step ahead of my responses

 

[Yeret]

Have you checked your spark plugs? If the engine is indeed flooding, the plugs are likely wet-fouled and won't fire, not to mention smell really gassy. This would at least confirm the problem.

 

[suede]

plugs are decent, and like i said, if its sat for a couple days, it will start and run like dog crap on the verge of dying for about 10-20 seconds and then its no dice till you let it set a few days and it will do the same thing

 

[dapepper9]

Could try unplugging the front 02 and attempting a start. Preset fuel conditions when you do so.

Also back at the beginning you mentioned 45psi fuel pressure and that it drops off when cranking. 45 is almost too low according to spec. Also you said that when a buddy poured fuel in the tb that was the closest you got to it running. Seems possible your fuel pump may not be able to keep up and isn't holding pressure.

 

[auskip07]

plugs are decent, and like i said, if its sat for a couple days, it will start and run like dog crap on the verge of dying for about 10-20 seconds and then its no dice till you let it set a few days and it will do the same thing

did you try removing your O2 sensor (pre cat) sounds a lot like your cat has collapsed and isn't letting your engine breath.

if your stated PSI is 50-55 then you're fine. If pouring gas down the intake doesn't help its not a supply issue.

 

[skinywhitejesus]

i dont actually know what im talking about .. so take this with a grain of salt.. but when u floor a modern vehicle it's actually killing fuel to try to clear a flood. .. since this is the only time your vehicle show's any signs of life id be looking for a reason for the injectors to be pulsing when they shouldnt be. coolant temp sensor keeps popping up when i think about it.. but since we dont know what the previous owner did to the truck a hinkey ground could also keep the injectors open during cranking. i would check the injector plugs with a analog meter during cranking to see if theyre being cycled. or whatever new stuff replaces a meter that reacts fast enough. ... hope some of this nonsense helps.

 

[dapepper9]

did you try removing your O2 sensor (pre cat) sounds a lot like your cat has collapsed and isn't letting your engine breath.

if your stated PSI is 50-55 then you're fine. If pouring gas down the intake doesn't help its not a supply issue.

Engine should still start and idle with collapsed cat. Just choke and bog under throttle.

Earlier he stated his psi was 45 but unsteadily. Also that pouring gas down was the closest it's gotten to staying running

 

[dapepper9]

I'm thinking possibly the regulator or fuel pump is screwed and not holding enough pressure causing you to run too lean to run

 

[dRAMbuie]

Engine should still start and idle with collapsed cat. Just choke and bog under throttle.

Earlier he stated his psi was 45 but unsteadily. Also that pouring gas down was the closest it's gotten to staying running

I'm honestly a bit out of my league on this one, but I can tell you I had a Toyota Corolla a few years back that suddenly wouldn't start. The issue was diagnosed as being a faulty O2 sensor.
Put a new sensor in and the problem went away.

To this day I don't know how an O2 sensor would do that, but there ya have it.

 

[Mohpar]

I'd say mess with o2s

 

[Rustycowl69]

I believe combustion requires 3 things: fuel; compression, and spark(includes spark timing).

 

[joepizuro]

Put some gas in the tank lol