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smadge
05-25-2010, 16:45
Hello all! I am new to the site although I have been following it for a while.

I am in search of some help/advice...

I have a 2001 2500HD. About 200k on it. About 2 months ago it started to run a little rough then went into limp mode. Changed fuel filter and it ran fine for a day then did the same thing. Shut it off and wait a minute or two and it runs fine for several miles then kinda misses a little and goes into limp mode again. Got home and smelled fuel so popped the hood, found some fuel on passenger side that covered pretty much everything. Talked to a fella that is a GM mechanic and was told that it was fuel injectors and GM was trying to decide whether or not they would provide parts and me pay for labor so I left it parked for a little over a month. No luck with GM so I had the codes ran and get P0207, P1261, P0700, P0742. Never have had any tranny problems except the first time I started it after sitting for over a month, it hesitated for a second when first put it in gear. So, hoping that these codes are not "real". Other codes seem to tell me I have a loose connection on cyc 7. Also, don't seem to get any pressure on the hand pump on top of the fuel filter.
Am I in the right ball park? Can't seem to find a leak; wires don't seem loose. Any ideas/tips/advice?

DmaxMaverick
05-25-2010, 17:02
Welcome aboard!

The fuel mess is likely the crankcase vent overflowing oil/fuel. Unique to the LB7, the vent is open to atmosphere, and the pipe ends at the lower/right (passenger) side of the engine. Rough running is typical, as there is little room for air in the crankcase, and the lower end is submerged. What's likely happened, is the injector(s) have failed, and are dumping fuel into the crankcase. The injectors and return lines are located under the valve covers. Good luck with GM. Although you are well past the extended warranty period, but I've been seeing a lot of reasonable help from GM in these cases. A good dealership service manager can really help with the process.

The tranny code was likely a temporary situation, and no damage indicated. It isn't uncommon for the torque converter to "drain back" after sitting for long periods. This can cause a hesitation upon gear engagement after the first cold start, and a corresponding DTC (trouble code).

smadge
05-25-2010, 17:24
Thanks. The vent being there kinda makes me feel better that maybe it isn't actually a leak...forgot to mention before that I pulled the oil dipstick and it smells normal and looks normal. The oil has looked good and never smells of diesel on changes.
Is there a way to tell if it is the injectors? From what I have seen the codes I am getting do not indicate failed injectors??
I have pretty much accepted the fact that I need to replace the injectors but have enough of a question in my mind to hold off a tad; I hate to spend the money and time on new injectors just to find out that it was something else.
If it is the injectors who are some good online guys to order through? See several online but nervous about how trustworthy they are...

More Power
05-26-2010, 10:20
"Fuel in oil" has been pretty thoughly discussed here (a search will likely turn up quite a few discussions), but you can use a clean white paper towel to check for fuel in oil. A single drop of straight oil off the dipstick placed on a white paper towel will create a single ring as the oil soaks into the towel. If there is fuel in the oil, there will be two concentric rings. The fuel component in the mix will travel faster/farther as it soaks into the towel.

Click the "Advertiser's Section" link at the top of the page for a list of vendors that offer injectors.

Jim

smadge
06-01-2010, 18:20
OK, from the best I can tell there is no fuel in the oil...oil levels unchanged; no smell; checked with drop on paper towel...oil looks god to me.

Still got p0207 and p1261 codes.

A little more looking around today after truck has sat in driveway for about a week. Found fuel on the wires coming out of the bottom of the water in fuel sensor... I think that is what it is...the plastic piece on bottom of the fuel filter.
Does this sound likely?

smadge
06-06-2010, 09:19
Found the head gasket to be leaking near number 7 cylinder...

while replacing what else should I knock out?

THEFERMANATOR
06-07-2010, 19:38
Definately re-seal the injector cups while you have it all apart. I used the new PERMATEX green sleeve retainer formula on mine and seems to be holding very well.

More Power
06-08-2010, 08:21
OK, from the best I can tell there is no fuel in the oil...oil levels unchanged; no smell; checked with drop on paper towel...oil looks god to me.

Still got p0207 and p1261 codes.

A little more looking around today after truck has sat in driveway for about a week. Found fuel on the wires coming out of the bottom of the water in fuel sensor... I think that is what it is...the plastic piece on bottom of the fuel filter.
Does this sound likely?

P1261 - The ECM detected a problem related to the high voltage circuit(s) for cylinder(s) 1, 4, 6 or 7. One or more of DTCs P0201, P0204, P0206 or P0207 will also likely be present when P1261 sets.

This could be due to a FICM, related electrical harness or an individual injector problem. Seems we've had more FICM harness problems discussed here than any other possibility. I'd start there though....

Leaking fuel filter assembly - check the air bleed screw on top of the housing or look for a leaking filter element o-ring.

Jim