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Fuel pressure loss.

CDW6212R

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Yes the injectors are run by the ground wire being triggered by the PCM.

The smoke you see should either be unrelated to what you have been doing with it, and run it and see how it is warmed up. Or the smoke is a lot, and it's time to check the cylinders with a leak down test. Head gaskets are very good except for odd rare models, and after over heating.
 


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98EdBomber

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I noticed the driver side exhaust manifold collector part where its bolted to the exhaust tube is soaked and stained with something liquid. Either coolant of fuel. Im guessing fuel.

The intake port next to the fuel injector on #6 was completely full of fuel when i removed the intake after i saw it smoking the first time. And #6 is on drivers side so im assuming the stain is because of fuel. That injector was stuck clean open. Dumping who knows how much fuel through the system.

So I returned those ones for a new set from a different seller and they seem good after the few tests i ran. Its still possible these new ones are sticking open while running but they did not stick open when i checked them on the fuel rail without engine running and pressurizing fuel pump. Bone dry so Im assuming they arent leaking when running but who knows. The old ones didnt start smoking until after maybe 5 minutes. So it was doing fine and then stuck open for some reason.

Im thinking all that old fuel flooded the exhaust and was burning off on my second start with the new set in. At least I hope thats the issue. I did check compression on all cylinders and they were 150psi +/-5%. If I had low compression Id have leak down. I dont see a reason to do a leakdown unless maybe you think theres a valve not sealing/bent/who knows and is letting a crap ton of oil by???

I did open up the valve covers too and didnt notice anything out of place really but that doesnt mean i dont have a bad valve. Just seems odd that it would have head gasket, valve, etc issue just because i changed injectors. Anyways, Ill try again in a few days and see what happens.
 




Mbrooks420

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If you dropped that much fuel you had better change that oil before running it, unless you want to smoke all your bearings.
 




CDW6212R

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Ditto, and the symptoms are not all from the same thing. Check the oil closely again, didn't you say you already changed it since the bad injectors were in it? Watch the oil and smell it etc, change it again if it seems anything but new while worrying about fuel in it.

The leak down test will find a bad head gasket, if that is a concern. It sounds more like fuel in the exhaust is the main worry at the moment.
 




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Yes it's quite possible you have fuel in the exhaust that takes a little heat to start burning inside, which would worry me, if it melts the cat. I wouldn't run it long after the smoke starts getting dense, instead repeating shorter run cycles trying to clear the exhaust out as harmlessly as possible.

If you happen to have an infrared temp sensor gun, you could monitor cat temperature with it, though it wouldn't surprise me if normal operating temp is above what some guns can measure so I would be looking more at rate of temp increase, if it suddenly shoots up at a fast rate once it hits a fuel ignition temperature... while if it were coolant cooking off, that would keep the temperature lower than normal till it's gone.
 




98EdBomber

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If you dropped that much fuel you had better change that oil before running it, unless you want to smoke all your bearings.
First thing I did. Also dropped the pan to look for shavings and got lucky. Which is also why I turned it off the second time. I really need a scan tool to see if its misfiring during next run test. Because it could be residual left over and not necessarily misfiring so if I see its misfiring and smoking i can shut if off immediately. If its smoking without a misfire and its not oil or coolant which im convinced it is not It should just be residual left over fuel burning off. Even though after a few days id think it should evaporate if lets says its pooled into the exhaust or cat for instance.
 




98EdBomber

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Yes it's quite possible you have fuel in the exhaust that takes a little heat to start burning inside, which would worry me, if it melts the cat. I wouldn't run it long after the smoke starts getting dense, instead repeating shorter run cycles trying to clear the exhaust out as harmlessly as possible.

If you happen to have an infrared temp sensor gun, you could monitor cat temperature with it, though it wouldn't surprise me if normal operating temp is above what some guns can measure so I would be looking more at rate of temp increase, if it suddenly shoots up at a fast rate once it hits a fuel ignition temperature... while if it were coolant cooking off, that would keep the temperature lower than normal till it's gone.
Good idea thanks. Do short 5 minute runs then shut it off and let it cool down.
 




98EdBomber

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Ran it again and heres whats going on

20210119_150314-1.jpg


20210119_152439-1.jpg
 




98EdBomber

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Didnt even let it run til warm. Ran really rough. I think I smoked a cylinder ring when the injector stuck open. But i checked compression and they were all near 150psi . I dont know what to think. Maybe its coolant? Dipstick came out clean?

That first puddle came out within 2 minutes. 2nd and 3rd startup it was dripping something. I wiped it up with a papertowl and lit it with a lighter and it didnt ignite whatsoever. Maybe coolant??? Its kinda cold outside right now so it will drip a bit due to condensation but not sure how much is too much. Im more concerned with the smoke honestly. Should I keep running it more?

Fuel pressure stays at 30psi when running and slowly drops to maybe 27 when i shut if off and holds there pretty much. I dont think my ionjectors are stuck open again? Where do i go from here?

EDIT: Ok after the 4th try it seemed to be clearing up after 5 monutes and almost to operating temp and I gave it some gas up to maybe 1500 rpms. Started smoking again. Shut it off. Fuel pressure dropped off the planet to 0. Gotta be injectors stuck again. If it was the fule pump check valve it wouldnt cause it to smoke. A leaking injector certainly would and since its flooding the cylinder out itll run like poo which it is.

I guess Ill suck it up and buy new ones. Not sure what else to think here.
 




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Complete lack of color seems strange for coolant, but it sure doesn't look like gas. Is there any chance you got bad gas with water in it?

Otherwise, after having done a compression test, there's leak down test, there's letting it cool then opening the radiator to look for bubbles forming while running, or one step further, a combustion leak detector, chemical test of the gas coming out there to confirm it's exhaust gas.
 




EB4X

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Smell the puddle on ground...does it have the "sweet smell" of coolant? I was thinking same thing about water in gas...since earlier you stated coolant levels remain normal....
White smoke is coolant or water.... black smoke gas.... blue smoke oil.... I know we all know this...but just stating...
 




98EdBomber

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Smell the puddle on ground...does it have the "sweet smell" of coolant? I was thinking same thing about water in gas...since earlier you stated coolant levels remain normal....
White smoke is coolant or water.... black smoke gas.... blue smoke oil.... I know we all know this...but just stating...
No sweet smell. Read my above post I edited it.
 




98EdBomber

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Complete lack of color seems strange for coolant, but it sure doesn't look like gas. Is there any chance you got bad gas with water in it?

Otherwise, after having done a compression test, there's leak down test, there's letting it cool then opening the radiator to look for bubbles forming while running, or one step further, a combustion leak detector, chemical test of the gas coming out there to confirm it's exhaust gas.
Lost fuel pressure after my last trial run. Almost got it to operating temp and it seemed like the smoke was going away and then i raised rpm to around 1500 and after maybe a minute it started smoking again. SO i shut it off and fuel pressure dropped to zero within a minute.

I think I have another bad injector stuck open. I may suck it up and buy new ones. Not sure what else is going on. No CEL so I doubt the PCM is going out or shorted the wires?
 




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If it were mine, I'd hold off on the injectors and wires and try to determine for certain if there's water getting in from coolant or the gas tank.

However if a short (wire OR PCM fault) is holding an injector open, while it still is you should see a voltage drop on that injector connector's ground pin compared to the others, between that pin and chassis ground.

I'd also be checking coolant level very carefully, maybe even drain the gas tank and put new E10-E15 fuel in before I kept redoing the fuel injectors, but I'm not there, maybe there's something I'm not picking up on.
 




98EdBomber

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If it were mine, I'd hold off on the injectors and wires and try to determine for certain if there's water getting in from coolant or the gas tank.

However if a short (wire OR PCM fault) is holding an injector open, you should see a voltage drop on that injector connector's ground pin compared to the others, between that pin and chassis ground.
Ill see if I can get a T pin in there. The injectors on pass side are deep in there. Quite a reach but I think its possible with some alligator clips and some long needle nose. I think the PCM throws 5v at it but not sure. I checked the connectors before putting everything back together this time but that doesnt confirm a problem when engine ON.

Power wires all had 12v and ground wires did not light up test light. That was with key on engine off.
 




CDW6212R

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Stop changing things and work out what is going on, don't change the injectors again. The fuel pressure dropping after shut down is very minor, ignore that for now, assume the injectors are working properly for now. What is ten times more important than the off psi, is the running psi. If it drops below 30psi, it's not enough, and 30psi is not really good, 32psi or more is better.

Keep a close eye and nose on the exhaust and main fluids. Get it running up to temperature, don't worry about revving it, just get it warmed up and fluids all looking right.
 




Mbrooks420

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I highly doubt you are getting an appreciable amount if water from the fuel.
 




98EdBomber

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I highly doubt you are getting an appreciable amount if water from the fuel.
I agree. I use good fuel from Chevron. Its never humid out here. I keep the tank full most of the time. BUT....the bottom of the muffler was dripping wet and it didnt smell sweet like coolant. It was chilly in the garage today with wind chill. Maybe 50F so most of that moisture if because of that. But its still baffling how much there was. Im assuming once the engine warms up and runs for a while that the dripping should stop?
 




C420sailor

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These things make a lot of water.

I drill a 1/16” hole in the tail pipe just behind the muffler on every new exhaust I install. Water collects here and rots the pipe out otherwise. You should see the puddle it leaves every morning...
 


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98EdBomber

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These things make a lot of water.

I drill a 1/16” hole in the tail pipe just behind the muffler on every new exhaust I install. Water collects here and rots the pipe out otherwise. You should see the puddle it leaves every morning...
Interesting. I definitely have drain holes. Just surprised how much water there was. Ive had this truck since it was new and i dont ever recall it dripping that much but i guess its normal?
 




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