Went from ROUGH idle to no start. HELP!

[Goliath]

Crank no fire. Its turning over good now that the batts are topped off. No my laptop is down right now so I cant use my program to scan for codes. Im waiting on a buddy of mine to get back from college and hes bringing over his handheld scanner. After I eat some lunch Im going to check the juice going to the fuel pump. (Just found my test light.) My boss gave me one day off so this thing HAS to be going by tomorrow.

 

[Tenn01PSD350]

I checked the oil first thing. No fuel there. I cant hear the pump running and when I crack the valve and turned the key on nothing comes out. I read a lable on the hood that says my truck has a fuel pump cutoff switch and that resetting it could resolve the problem. (Thats exactly what it says "Resetting the switch could resolve the problem") Where is this switch at? In the fuse box? Thanks a ton guys.

The switch is behind the kickpanel passenger side. There is even a hole to push it so the panel does not need to come off. I would start by running a jumper wire directly to the hot side terminal on the fuel pump from the positive battery post or known hot 12 supply. If the pump comes on, check your fuse and try bypassing the fuel pump reset switch. If it does not come on and you are sure it is grounded and getting 12v, your pump is dead. Hope this helps.

Edit: yeah, test light is easier. Jumping the pump just assures you that you are getting a solid 12v. A light will only tell you that there is voltage present.

 

[Goliath]

Great. Thanks guys. Im going to be out for a little while. My thumbs are sore (been talking to you all on my blackberry) and I gotta get back on my truck. All the help has been great. I'll post up what I find out.

 

[Goliath]

New News

My pump is now working after I reset the switch. Still no start. Tried to let it bleed off the air in the fuel lines. Still no start. So the last things to check are the oil pump and the glow plugs. Anyone have an idea of where to go from here? Is there a way to check either of these things?

 

[Tenn01PSD350]

As far as the GPs, you could plug the block heater in for about 30 minutes and not need them or at least rule that out. To test the GPR, place a test lead on the large terminal that goes from GPR to the injector harness, Not the one that goes to the battery. Place the other lead on a good ground. With key off there should be no voltage. When you trun the key on there should be a minimum of 10.5 volts but it ought to be what the batteries show. (Did you know the AIH relay works as an emergency GPR, just transfer all the wires)

Pull the allen head plug off of the top of the HPOP reservoir and make sure the oil level in there is within 1 inch of the threads. If not, fill it with clean oil and quickly try to start the truck.

Are you getting a good stream of fuel through your filter when you have the pump on and open the drain valve momentarily? How old is that fuel filter?

EDIT: you can also jump the large terminals like on a starter solenoid. BTW, make sure both of your injector harnesses are securely connected where they go into both valve covers.

 

[Goliath]

The fuel filter is about 2 weeks old. Im about to pull it and clean out the bowl and spray the filter out with air just to make sure there is not any water in there. When I crack open the valve I get a pretty good flow of fuel. I changed the oil since Im about 1000 miles overdue and thought on a whim that the oil might be too thin and not able to build enough pressure. That wasnt it either. I plugged in the block heater before I changed the oil so Im going to wait a little bit and see if that works. I'll check the connectors too while I'm out there. After resetting the fuel pump switch it seems like it wants to crank now but it just wont fire up. Thanks for the tip about using the AIH relay Tenn.

 

[Tenn01PSD350]

The fuel filter is about 2 weeks old. Im about to pull it and clean out the bowl and spray the filter out with air just to make sure there is not any water in there. Thanks for the tip about using the AIH relay Tenn.

No need for that. If you drained all the fuel out of the bowl once, there will not be enough left there to bother with. And you're welcome.

By looks like it is trying to start, do you mean it is actually showing some kind of smoke out the tailpipe? If not, it is not trying to start. You may be in for some cranking if you have air in your lines. Don't burn up the starter.

Make sure to check that HPOP reservoir too. Good luck.

EDIT: Make sure that your fuel pump stays running. Even if you need to jump it.

 

[Goliath]

Then its not even trying to start. It just sounds like it is almost about to catch but it doesnt. I cracked the lid on the fuel bowl and there was no fuel in it. But all day when I opened the vavle it would come out. Is it possible to have and intermittent fuel pump problem? Could it be going out and not have enough pressure to crank? I can put my hand on it with the key on and it starts off really loud the gets quite after about 2-3 seconds. Its a little over $200 so I don't really want to pay for a new one if thats not it. Thanks again for all the support.

 

[Tenn01PSD350]

Remove the bowl lid and have someone turn the key, or better yet, jumper the pump from the battery until the bowl is about full. A couple seconds. Then cap it and try, but you need to do a pressure check on the system. $10 gauge and fittings.

I am suspecting a fuel problem. You might even want to remove the fuel line in front of the pump, remove filler cap of the tank, and blow some compressed air through the line into the tank and hopefully clear a possible obstruction in the line or most likely the mixing chamber of pickup foot in the tank.

It is getting late, and you need to move quickly now if you plan to take this truck to work tomorrow.

Did you ever check the HPOP reservoir oil level?

 

[Goliath]

Yea. i'm still working on it. I'm not in so big of a rush now since my brother said I could borrow his truck to go to work in. But its a Duramax... Bummer. I checked the oil level in the HPOP and it was good. Even tried topping it off and still nothing. I really thinks its a fuel delivery problem. The pump is pumping now but nothing is coming out. Im gonna get up early in the morning and try the compressed air trick. This wont damage the pump will it? Do I need to have the filler cap off to realease the pressure? You've all been a ton of help but if I can't figure out the problem then I'm going to have to break down and take it to a mechanic. Only problem is I honestly wouldnt trust any of the mechanics around here to even change my oil. Maybe I'll just load it on the trailer and let my dad run it to the Monroe dealership when he gets in next week... I'm going to miss my baby.