engine cuts out but doesn't turn off

[prodjay10]

Any idea why this happens?

It won't start unless I use starter fluid. It runs after that.

It'll cut out then keep running consistently.

[prodjay10]

Here is a youtube link to the vid. You can hear it cut out twice before I disconnect power. I didn't want to run it too long since I don't have a radiator hooked up yet.

https://youtu.be/tydswaR2Wic

[ls1nova71]

What are you using for fuel delivery? Is the pressure 58psi? Also, you should take the belt off of it when running it on the garage floor like that, the water pump and power steering pumps dont like to be run dry, not to mention the fan is a hazard.

[prodjay10]

Good points. I have a fuel pump connected ac Delco EP381 sitting in fuel tank with sender.

I will check fuel pressure tomorrow.

Something I’m not sure of is whether I have the flex fuel injectors and if that matters.
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[prodjay10]

I'm now pretty sure I have the flex fuel injectors. It has the uscar connector.

[ls1nova71]

Not sure how you have it wired at the moment, but does the fuel pump prime when you put power to the main ignition relay?

[prodjay10]

Originally Posted by ls1nova71

Not sure how you have it wired at the moment, but does the fuel pump prime when you put power to the main ignition relay?

The fuel pump primes when I connect power to relay/ fuse box.
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[Wgesnerjr]

I run the EP381 on my flex fuel 5.3 with no issues. pressure should be fine.

Do you have a return line? I made sure to plumb it back to the gas can during my test fire.

Also, should it have a MAF?

[ls1nova71]

I missed the not having a MAF, probably because I was waiting for a hand to get hit by the fan! But yeah, try hooking it up and see if it starts better. Make sure it's going the right direction and tape it to the throttle body, it wont work if it's just plugged in but not in the air stream going to the engine.

[prodjay10]

I do have the return line going back to tank.

The guy that tuned my PCM said his files show it was the flex fuel pcm so everything should be fine there.

MAF is connected but not taped to throttle body. I have seen videos on the line that show an engine starting, running and idling fine with out the maf.

I honestly was more worried about the gas catching fire than the fan. I’m surprised it didn’t roll over since it wanted to rotate when starting.

I’m gonna check codes next to see why. I probably have a vacuum leak.
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[mongocanfly]

( I have seen videos on the line that show an engine starting, running and idling fine with out the maf. )

dont believe everything you see on youtube....

thats risky trying to start a engine like that...and yes i know its been done before...just saying its risky

[Wgesnerjr]

I would ditch the fan and tape the MAF to the Throttle body. Costs nothing but time and some tape.

[ls1nova71]

Originally Posted by prodjay10

MAF is connected but not taped to throttle body. I have seen videos on the line that show an engine starting, running and idling fine with out the maf.
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This is likley your problem, I'm surprised you got it to run that good. It will run better without the MAF hooked up at all, which is what you were seeing. If the MAF is hooked up, but not hooked to the throttle body, it will be sensing the completely wrong amount of air going in the engine so the PCM is dealing with false information. Either unhook it or better yet, tape it to the TB and it should run a lot better.

[prodjay10]

Got the obd2 connector hooked up and got a tps code. I fixed that and now if fires right up but won’t stay running for more than a few seconds. It kinda idles lower and lower till it dies. MAF is taped on the throttle body.

Next I need to check fuel pressure. Doing this at work so I don’t have much time to get to it.

Only two codes I get now are mil and trans.
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[prodjay10]

Removed MAF and it fires right up and idles high. Doesn’t turn off.
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