I Recently Transplanted A Duramax Drivetrain From A 02 To My 01. The Motor Cranks, But Will Not Fire. I Was Told I Probably Have Air In The Fuel Lines. Does Any One Know How To Bleed The Injector Lines?

if it is air in the lines we just keep priming the filter then crank it. alternate back and forth untill it fires. if not maybe you left something important unplugged a scan of codes may point you to something.

Do you have a lift pump or is it a stock fuel system? All it took for us was cranking, opening the bleed screw for a bit, and also try relieving air with the schraeder valve by front side of engine. Hope this helps...:rolleyes::eek: Also, make sure all fittings and connections are tight especially injector feeds, fuel hoses in and around ficm, & filter.

Btw, lift pump is awesome help for this.

exactly, make sure you loosen the bleeder screw on the pump above the filter, this will aid in getting the fuel primed correctly.

Thanks for all the replies. I have bleed the fuel filter at least 10 times, but it still won't start. I have scanned it and it comes back with no codes. I check the glow plugs and each one is cycling on when the key is turned on. I removed the return fuel line and verified it is pumping fuel when it is turning over. It has the stock injection pump. Any other ideas.

Crack the lines at the FICM and bleed the air from there.

Will I have to replace the sealing washers if I open them up?

I tried opening up the lines at the FICM and there is barely any fuel there. I even tried cranking it with each side open. I have fuel at the schrader valve and the fuel filter. HELP PLEASE!!!

Any other ideas would be greatly appreciated.

Any other ideas. Still can't get it started.

This sounds like what happened to me a while back when I ran out of fuel. Bled the system and primed it and It would crank but wouldn't start.

Turns out I had to replace the batteries and it started right up.

If you have another vehicle around, try hooking up the jumper cables and assist your batteries or charge them with a charger. If it doesn't work, swap the batteries and see if that works.

So you have fuel at the bleeder screw on top of the filter, and at the schraeder valve? Any other visible fuel leaks?

Try what kasl33 said. Sounds interesting, may be just a simple issue overlooked.

Yes I have fuel at the bleeder screw and schrader valve. I can't see a leak anywhere. I have 2 brand new optima's in it. I am using a charger as I crank it. The truck sat for 6 months before motor was swapped. Could the fuel be bad? Would color should the fuel be. I have never really looked at diesel fuel. Mine is yellow in color.

CHECK THE BATTERIES! I went through this and you are describing the problem EXACTLY.

I had two brand new OPTIMA yellow tops that sat in my garage for a month before I put them in. One of the two ended up being BAD. Even though your batteries are new, they can still be bad.

Brand new batteries with a charger connected. I have verified voltage at 13.2V with charger connected.

If you have some help and an air compressor you can bleed the fuel system as follows but be careful when doing it. Locate the CP3 in the front center of the engine. Find the fuel supply line and disconnect it. Route the hose to a can to catch the fuel. With someone holding and watching the catch can remove the gas tank cap and slowly add air pressure into the tank. If does not take a lot of pressure so do not try as the tank is plastic and will expand. Continue adding air in small shots to the tank until the helper say you have fuel running out of the line with no air bubbles. Attach the line back on the CP3 and pump the primer on the filter. At that point it ready to start up.

Do you mean the line that returns the fuel back to the tank??

Took both batteries to the interstate service center and both batteries came back good. Any other ideas????

Double check all the wire connections are good. Sometimes the spade part in the connector can get pushed back and out, not making contact. (Just a guess).

Do you have a scan code reader? Any codes?

jb

Do you mean the line that returns the fuel back to the tank??

No, Take the fan belt off then remove the AC compressor. Lift compressor to the side and you will be able to see the CP3. There is a rubber feed line that brings the fuel to the pump. It's held on with a hose clamp and enters the pump next to the regulator. Take that hose off and route to a can.

Triple checked all wiring. No codes.

If you have fuel at the filter bleed screw, and you pump the primer till hard, it should fire with the 10-12 second crank trigger timeout setting. You likely have an electrical plug issue. Even if one injector harness is off, no fire.. Could be loose, dirt, etc. I had ice in one of mine in the dead of winter. I had it apart and a little water sat int he open connector and froze. No start. If you have fuel and are sure it electrical. These are simple motors when it comes to just running. Running right is a whole set of messy issues. It takes little to start a diesel per say. You didn't do something to cause a loss of high pressure fuel did you. The pump can pump all day and not build high pressure. You can scan the commanded and actual rail pressure with a scan tool. It won't fire without seeing about 5300psi or something like that i think, been a while since i looked at mine. I actually made a gauge to monitor my rail pressure when the stupid steeler couldn't figure it out.

before others call BS, yes, my gauge will read 30k psi.. and is steel 1/4 line full seam welded with no fittings except the line tap. I blew apart an adapter fitting first time. lol

I think I have found my problem. I had a fuel line sucking air at the flex line at the transmission. I have order new fuel lines, but they are backordered. I also received my new Air Dog lift pump today. Very nice kit except for the pickup line. I ordered a billet pick up from Kennedy Diesel.

When I had completed my conversion it would not start right off the bat. Ends up the BCM needed to be recalibrated to the new ECM. It is called a relearn. It takes 30min. to complete. If you used the engine computer from the 02 then you need to do this. To complete a relearn you turn the key to the ON position for 10min, turn to OFFr 10sec, ON for 10min, OFF for 10sec, ON for 10min. then turn OFF. The next time you turn it to the ON position all of the computers will relearn eachothers codes. There are like 4 or 5 different computers on board that all have to talk to eachother in order to run. It worked the first time and the Yukon fired right up. Other wise it just turned over no mater how many times I primed it.

We just changed my injector pump this weekend and we couldnt get the truck to start for a long time. We did what diesel tech mention earlier in this thread, it finally got it.

Boisebiker is possibly right on target, check to see if the "Security" light is lit when you are trying to crank, if so, you need to do what he said. With one little exception, dont turn the key off until the security light turns off! It can take 5 minutes to 15, depending on the other onboard controllers. Learned this the hard way myself. BTW, when you turn the key on in the process, turn it until it is in the run position, not the crank! Do not crank the engine as it can sometimes take you back to square 1!

Be patient, you will get it running.

Tony

I agree with a few of the posters. I do not think you will be able to start the duramax with the prime pump on the fuel filter if you have air downstream of the CP3. I have found the best way to do it is have a friend crack an injector line while you are cranking the truck over. Have him tighten it back up before you stop cranking. Keep repeating this until you have bled enough air to all diesel to be pushed to an injector. The duramax will do the rest.

boisebiker you are the man. I looked in my service manual and followed the procedure for relearn of the security system and it started.

Congrats!!!