No boost

[Landon730]

Revisit posts 4 & 5

Thats with the truck not running and the actuator unhooked. Should it still be stiff? I can't move the actuator at all and from reading yalls comments is good.

 

[Will L.]

Wastegate feels like nothing’s even hooked to it cause it turns so easy. And it’s lived in Arkansas where there’s no salt it has not even a speck of rust. I can’t even hear a turbo whistle though so I don’t really think it’s a leak. I could be wrong but I’ll look

Thats with the truck not running and the actuator unhooked. Should it still be stiff? I can't move the actuator at all and from reading yalls comments is good.

Ok. My mind is broken.

I took that first one as engine running since you couldn’t hear the turbo whistle...

I need to let my head clear (more from things at work today than this) and try to think it through tomorrow.

 

[Landon730]

Ok. My mind is broken.

I took that first one as engine running since you couldn’t hear the turbo whistle...

I need to let my head clear (more from things at work today than this) and try to think it through tomorrow.

Your fine lol I know what you mean I have those days

 

[THEFERMANATOR]

Which codes come up? They should start with a P(powertrain), U(communications), B(body), abd a few others for other systems. Need to know the EXACT codes starting with the letter. And forget most everything you know from s 6.5 when worki g on a DURAMAX. You're now dealing in high voltage(96 volt) injectors, high pressure CP3 pump, and a ECM & FICM to run it. Injector circuit codes are bad news and will shut down all 4 injectors on the driver, so if you have an open circuit on each driver group, it will not try and run. This is NOT an engine to guess with or play around on. ALOT of damage can be done to them just by working on them if you don't know what you're dealing with.

 

[Landon730]

Which codes come up? They should start with a P(powertrain), U(communications), B(body), abd a few others for other systems. Need to know the EXACT codes starting with the letter. And forget most everything you know from s 6.5 when worki g on a DURAMAX. You're now dealing in high voltage(96 volt) injectors, high pressure CP3 pump, and a ECM & FICM to run it. Injector circuit codes are bad news and will shut down all 4 injectors on the driver, so if you have an open circuit on each driver group, it will not try and run. This is NOT an engine to guess with or play around on. ALOT of damage can be done to them just by working on them if you don't know what you're dealing with.

They were all P codes. I just don't understand injector circuit codes when the injectors are hooked up. I have a video of it running that I'm sure would greatly help yall but i don't know how to post it. The last thing I want to do is cause more damage. Could it possibly be the ECM? Its stuck in limp mode with a endless list of codes. I cleared them and even without turning the key off or starting the truck they immediately come back

 

[THEFERMANATOR]

Injector circuit codes can be a bad solenoid coil in the injector, wiring problem, or a bad FICM. I highly doubt it's the ECM. Opening ANY part of the fuel system up to work on it has ruined MANY an injector and CP3. The FICM has 2 output drivers to control the injectors, so it groups the injector circuits into 2 groups of 4, and triggers them in alternating order(so 1 driver is charging while the other is being used). Because of how the FICM is designed, if even 1 injector in that group of 4 has a problem, it has to shut all 4 of them off(hence all the LLY's only running on 4 cylinders when the 2 or 7 injector plug gives trouble), and you only run on 4 cylinders.

We need an exact list of ALL the codes that instantly return so they can be grouped together and find the correct diag trees to start with.

 

[Landon730]

Injector circuit codes can be a bad solenoid coil in the injector, wiring problem, or a bad FICM. I highly doubt it's the ECM. Opening ANY part of the fuel system up to work on it has ruined MANY an injector and CP3. The FICM has 2 output drivers to control the injectors, so it groups the injector circuits into 2 groups of 4, and triggers them in alternating order(so 1 driver is charging while the other is being used). Because of how the FICM is designed, if even 1 injector in that group of 4 has a problem, it has to shut all 4 of them off(hence all the LLY's only running on 4 cylinders when the 2 or 7 injector plug gives trouble), and you only run on 4 cylinders.

We need an exact list of ALL the codes that instantly return so they can be grouped together and find the correct diag trees to start with.

Ok I gotta go put the valve cover back on and I'll get every single code for you. Had the valve cover off because I ohmed out the plugs and I thought one didn't ohm right, turns out I had a bad connection with my leads. I'll get you the codes and make sure by you before a start randomly buying parts but with the symptoms so far, I could definitely see the FICM being bad. We bought a new one for my dads LB7 and it ended up being fine. If I can ever find the old one to put on and try that would be awesome.

 

[THEFERMANATOR]

I doubt it's your FICM, you most likely have a chafed wire near the alternator, or a pin pushed out of 1 of the bale connectors. Removing the fuel lines to get the valve covers off has ruined MANY an LB7 injector. When you take the line loose, all the built up crud drops right into the injector inlet, and ruins the injector. That's why you try at all cost's not to open a fuel line unless you must.

 

[Landon730]

I doubt it's your FICM, you most likely have a chafed wire near the alternator, or a pin pushed out of 1 of the bale connectors. Removing the fuel lines to get the valve covers off has ruined MANY an LB7 injector. When you take the line loose, all the built up crud drops right into the injector inlet, and ruins the injector. That's why you try at all cost's not to open a fuel line unless you must.

I second the chaffed wire or bad connection. I got it back together this morning and it ran perfect. I drove it around all day and here I am, back to the same problem. Batteries are unhooked and I'm taking a break from it. I'll go out in a little while and check on it

 

[Landon730]

I doubt it's your FICM, you most likely have a chafed wire near the alternator, or a pin pushed out of 1 of the bale connectors. Removing the fuel lines to get the valve covers off has ruined MANY an LB7 injector. When you take the line loose, all the built up crud drops right into the injector inlet, and ruins the injector. That's why you try at all cost's not to open a fuel line unless you must.

Only codes now are P0201, P0204, P0206, P0207, and P2146. Praying it’s not injectors

 

[THEFERMANATOR]

I would be checking the power wires to the FICM. You have codes for 4 injector circuits and a group A FICM circuit code. I'll try to get my laptop out and pull up the flow charts tonight or tommorrow.

 

[Landon730]

I would be checking the power wires to the FICM. You have codes for 4 injector circuits and a group A FICM circuit code. I'll try to get my laptop out and pull up the flow charts tonight or tommorrow.

I looked at the wires in the little plastic holder behind the alternator and I didn't see any that were messed up. What do I need to look for on those power wires going to the FICM?

 

[THEFERMANATOR]

Found this.

Duramax: Injector Circuit Diagnostics

Diagnostic challenges with a GM Duramax: Limp mode, fuel injectors, and the complexities of modern automotive technology explored in this story.

www.underhoodservice.com

 

[Landon730]

Found this.

Duramax: Injector Circuit Diagnostics

Diagnostic challenges with a GM Duramax: Limp mode, fuel injectors, and the complexities of modern automotive technology explored in this story.

www.underhoodservice.com

I’m just scared at trying to buy and change a injector and it not work. Only reason I’m scared to is it ran completely fine for a few hours today. I’ll look over every inch of wire right here by the ficm and see what I find

 

[Landon730]

I would be checking the power wires to the FICM. You have codes for 4 injector circuits and a group A FICM circuit code. I'll try to get my laptop out and pull up the flow charts tonight or tommorrow.

I don’t know if this will help any but this is what my tuner is reading the injectors at. They all are very close just fluctuate a couple decimals. None of the wires have any chaffing from the FICM bracket. I ohmed all 8 injectors at the plug on top and they all ohmed out the same. (Snap On ohm meter). I’m at a complete loss. It ran like new all day until this evening it jacked up again. All I did was pull the valve cover, check to make sure the wires were hooked up, and put everything back together. This morning I put it back together and hooked the batteries back up and she ran perfect.

 

[Landon730]

Found this.

Duramax: Injector Circuit Diagnostics

Diagnostic challenges with a GM Duramax: Limp mode, fuel injectors, and the complexities of modern automotive technology explored in this story.

www.underhoodservice.com

UPDATE: 3 injectors in passenger side read correctly, .3-.4 ohms while the very back injector only read .06 ohms. Do I need a new injector?

 

[Landon730]

UPDATE: 3 injectors in passenger side read correctly, .3-.4 ohms while the very back injector only read .06 ohms. Do I need a new injector?

Still not it, ohmed at the pins and they ohmed right. Put it together without valve cover and it ran right so I put the valve cover on and drove it, now I'm here. It started white smoking and then smoking under the hood which I think was the upper valve cover leaking. Now it won’t start at all. The only codes now are 2146 and 2149.

 

[THEFERMANATOR]

I had to look under an 04, but here is the diag flow charts for those 2 codes. And the injector code test.

 

[Landon730]

Well I got it fixed.. was the injector harness being smashed by the valve cover. But then I went and drove it, did great, got home answer went inside for awhile and then came back out to drive it and something blew so now there’s a solid stream of oil coming out of the hole in the bell housing where it meets the motor. No drip just instand stream.