I have a ‘07 LBZ with 105,000 miles that I purchased new 10/18/06. Shortly after purchasing it, I installed a K&N air filter followed by a Banks six gun programmer with speed loader. I have kept it on the #3 setting (settings 1-6 with #1 being stock). Shortly after the Banks was put on, the P0402 code came up, I took it to the dealership (under warranty), and it was determined the code was caused by the excess airflow caused by the K&N filter. He recommended I put the stock air filter back on. I called Banks and they didn’t have any advice apart from what the dealership said. I’ve been living with that code since (code resolves when I put Banks on #1). Several years ago the truck began to periodically go into limp mode if I hit the gas hard, especially from a near standstill. Recently, I got the limp mode under minimal acceleration. I purchased a code reader, and the P0087 code came up as well as the codes for two bad glow plugs. I replaced the glow plugs, and the bad glow plug codes resolved. The P0087 was intermittent, always occurring with limp mode, resolving with regular driving. I read the info about collapsing fuel lines (GM Technical Service Bulletin #PIP 4526). The fuel lines don’t seem to be a problem (not soft even after being warm). I put the Banks on #1 just so it would be at stock settings. To eliminate the fuel line possibility, I purchased the recommended fuel lines. Literally on the way home, the truck started running rough (like a cylinder was not firing), worse at idle and low speed, initially better (resolved) at higher speed. A little later (still on the way home) it began to run rough at all speeds, though still worse at low speed and idle. The engine light spontaneously turned off (P0402 code resolved) while driving home. I changed the fuel filter. It is running rough at cold idle, runs a little better after warming and with higher rpm. I’m getting no error codes right now. It seems to me it’s probably the fuel pressure regulator, fuel pump, and/or injectors (injectors 1.5 months out of warranty....) I was going to buy the KD Fuel Filter Restriction/Lift Pump Psi Gauge Kit for Duramax, but I realized I don’t know enough right now, and I just don’t have enough time to fix what may be wrong. I’m raising the white flag. (As Clint Eastwood said, “A man’s got to know his limitations.”) I thought about taking my truck to the local Chevy dealership, but after reading the forums, I think I need somebody who specializes in diesels. I live in extreme north Georgia, about 15 min from North Carolina in the middle of the state (from East to West). Does anyone know a knowledgeable diesel mechanic in this area? I’m also interested in putting some gauges on the truck to better monitor what’s happening as well as possibly installing the EGR blocker so I can get rid of the P0402 code. I really need somebody to take a look/diagnose the problem and help me make some decisions. Any advice/recs would be greatly appreciated.
Need Duramax mechanic in North Georgia
- Thread starter bmoody
- Start date
Get a fuel pressure guage and monitor supply pressure.
Verify good supply.
Next check injector retu rn rates replace high return injectors.
Problem still not solved replace cp3 pump after checking fuel regulator.
If any of this is not something you feel comfortable with stick to plan a and take it to a pro.
Good luck and be aware this type of code can be a plugged fuel filter to contaminents in fuel that take out a ten grand fuel system
Sent from my SPH-L300 using Tapatalk
Verify good supply.
Next check injector retu rn rates replace high return injectors.
Problem still not solved replace cp3 pump after checking fuel regulator.
If any of this is not something you feel comfortable with stick to plan a and take it to a pro.
Good luck and be aware this type of code can be a plugged fuel filter to contaminents in fuel that take out a ten grand fuel system
Sent from my SPH-L300 using Tapatalk
Thanks to the PMs I received and the advice from jkholder. I purchased the Kennedy Diesel fuel gauge, and it was reading normal under idle and 3000 rpm. So I called Diesel Technology Source in Monroe, GA (they were very helpful) and was about to drive it there when I decided to run by the local dealership because I wanted to know if it was injector(s), cp3 pump or fuel pressure regulator (FPR). On the way over to the dealership it started running better, and by the time I got there it was almost back to normal. The diesel mechanic ("...been working on diesels for 13 years") connected Tech 2 and found two injectors more than 4 mm3 different from the other six. Tested it at about 24,000 psi and cp3 and FPR were okay. Did some additional testing and checked injectors again. Now, only #3 injector was off as before. Suggested I run some fuel additive and call back in a few days if not better. So, I did, and truck ran great until today when I filled the tank at a station that truckers use a lot (recommended by the dealership mechanic). Pulled out of station and immediately it started running rough and threw P0606 code. Limped back to dealership at 30 mph. Disconnected Banks 6 gun and it ran (and is still running) normal. So, it seems the Banks is my problem. No place on tuner to update. Gonna have to replace it with another brand. What do you recommend?
Again, thanks for all the help. This is a great forum.
Again, thanks for all the help. This is a great forum.
Efi live for sure.
If you don't have a shop close look into an autocal
Sent from my SPH-L300 using Tapatalk
If you don't have a shop close look into an autocal
Sent from my SPH-L300 using Tapatalk