SiFlyBy
Ricer
- Joined
- Jan 12, 2010
- Messages
- 15
Well, I gues this is my introduction post. My name is Chris and I am diesel and automotive technician. Most of my experience and training is from Ford but I recently started working for an independent shop which is becoming an exciting and, as you read on, a challenging experience. I have a problem with a Duramax that, so far, no one I have talked to( and alot of GM experienced fellows in there) has ever come across. So here it is:
I have a 04 LB7 that would not run, I checked everything I could think of and came to the conclusion that it was a problem of bad fuel. I disconnected the suction line to the pump and fed it clean fuel from a funnel. After a minute or so of cranking it started, but was running very poorly and backfiring through the intake. I decided to take a closer look, removed the fuel injector lines and found rusty deposits in them and the fuel injectors. After seeing this I decided it was time for 8 new injectors and a new injection pump. While I was replacing the injectors I also noticed that ALL 8 exhaust pushrods are bent...So my boss and I tossed some theories around and didnt' worry about it much. I installed the injectors, pump and pushrods. Reassembled the engine and got it started after bleeding the air from the fuel system. It ran good for a short while, shut it down and started back up and it was missing and rattling and running generally crappy backfiring out the intake again. I removed the RH valvecover today and what do I find? Bent exhaust pushrods.
I talked with a former co-worker who is also a Ford Senior Master Tech and I think he had the most reasonable thoughts on the matter: That somehow the injection timing is off...thinking about it know it may make sense that it is about 180 degrees off(by crankshaft revolutions) to cause all and only the exhaust pushrods to bend.
If anyone has any thoughts I would much appreciate it.
Thanks in advance,
Chris
I have a 04 LB7 that would not run, I checked everything I could think of and came to the conclusion that it was a problem of bad fuel. I disconnected the suction line to the pump and fed it clean fuel from a funnel. After a minute or so of cranking it started, but was running very poorly and backfiring through the intake. I decided to take a closer look, removed the fuel injector lines and found rusty deposits in them and the fuel injectors. After seeing this I decided it was time for 8 new injectors and a new injection pump. While I was replacing the injectors I also noticed that ALL 8 exhaust pushrods are bent...So my boss and I tossed some theories around and didnt' worry about it much. I installed the injectors, pump and pushrods. Reassembled the engine and got it started after bleeding the air from the fuel system. It ran good for a short while, shut it down and started back up and it was missing and rattling and running generally crappy backfiring out the intake again. I removed the RH valvecover today and what do I find? Bent exhaust pushrods.
I talked with a former co-worker who is also a Ford Senior Master Tech and I think he had the most reasonable thoughts on the matter: That somehow the injection timing is off...thinking about it know it may make sense that it is about 180 degrees off(by crankshaft revolutions) to cause all and only the exhaust pushrods to bend.
If anyone has any thoughts I would much appreciate it.
Thanks in advance,
Chris