LB7 modification: Daily Driver/Tow Duramax

The hole in the transfer case will be at about 2-o'clock from the output shaft. They generally do not leak while sitting, but leak while driving and if it is leaking could very well be dry by now... It is best to check the fluid level on the T-case. If it is low or empty you likely have a case that has been rubbed through. The Merchant Automotive solution to fix Pump Rub leaks seems to be the best to me. I believe they also make the one that PPE sells so get whichever of the two that you can at the best price...

As for the intake heater delete, I would go with the Fleece plug because it has a good seal for the boost pressure and is threaded so you can use it as the location for your boost gauge. I'm not sure the price but it won't break the bank.
 
for the intake heater delete i just pulled the IAT out and cut the coil out and welded the center up so its sealed.
 
Well I've had this truck about 20 days or so and yesterday, driving 25mph, it suddenly started to knock and puke black smoke. I pulled over about 200 yards later and trailered it home. It didn't seem to exhibit any warning signs that I noticed, however it's the first time we've had the truck down to 1/4 tank since we bought it. There is no blow by or "puffing" out the oil cap and the second set of injectors were allegedly done about 32,000 miles ago.

This is not my truck, but this is pretty much what it's doing:
[ame="http://www.youtube.com/watch?v=mAhoMz7q-xk"]http://www.youtube.com/watch?v=mAhoMz7q-xk[/ame]
and
[ame="http://www.youtube.com/watch?v=DiPrgaTdmzc"]http://www.youtube.com/watch?v=DiPrgaTdmzc[/ame]


My logic tells me it's an injector stuck open. I'm relatively green with Duramax motors, but figured I'd ask what diagnostics I should perform to find the problem. A dealership buddy said to check the wiring harness, which I have visually, but with no luck. I found this in my searches: http://www.dieselpowermag.com/tech/c...verado_2500hd/

I'm not much of an electronics guy, but I do have a multi-meter. If someone could break down a procedure on how to check the wiring harness and eliminate that variable first, I would greatly appreciate it.

I do have that PPE programmer, but it's off at PPE for an update. The dash isn't showing a SES light while running, but I'm not sure if they illuminate for all codes. At this point I'm thinking about jumping straight to EFI live for the sheer diagnostics, especially since this situation popped up.

This sure put the brakes on my Friday night activities :doh:
 
Bersaglieri said:
Right? This truck doens't even make 350hp as it sits lol.

I asked PPE about whether is was even worth sending in, since I wasn't planning on using the "big" tunes. She explained the tunes are similar to a degree, but updating the tuner allows for GM updates without causing tuner/ecm compatibility issues. I'm not sure if the tuner would work with the newer models I'll have to ask about that. The manual says 2001-2005 LB7/LLY and 2006 H1 Duramax.
Click to expand...

I can't sing praises of PPE after my experience with them. After my tuner was there for a week they finally called me and claimed I needed to pay them $150 to get "the latest and greatest tunes". I explained I just needed an update, didn't need big HP tunes, truck is bone stock, and that the girl on the phone told me updates were free. I was told $150 was a steal because I was getting "the latest and greatest tunes" that other people pay thousands of dollars for. After asking to be transferred to someone else, I was told the $150 was because it was locked. However I explained it was not locked. Then it was finally explained to me that the $150 wasn't for new tunes, it was because an update would necessitate a new board. I tried negotiating a price but $150 was the standard price that couldn't be changed. The new board would make it compatible with trucks from 2001 to 2010. So I figured I'd just get it fixed up. I gave them my credit card number to bill and waited. About 3 weeks went by and no tuner showed up. I finally called, thinking it got lost in shipping, and they claimed it wasn't there, that it was shipped. After hounding them for a few days for a tracking number, it mysteriously showed up. However it had not been updated. I told them to just ship it back and cut my $40 loss in shipping. They did try to make it up to me by offering discounts on a twin turbo kit for my truck, of course it's stock so it had no use for that. I asked for a discount on the updated board instead, they said absolutely not, so I said send it back.

Since PPE was playing around with my tuner for about a month, I called ATP/Idaho Rob and have EFI live at my disposal. The V2 showed up in two days.

Truck still has the stuck injector, I plan to mess with it after I move, so things are on pause until then.

PS Bac, I now own a PPE boost valve. :Cheer:
 
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I'm not 100% on this, but if there is a short in the harness somewhere the ecm shuts down the whole bank? If one is stuck, EFI will show a high NEGATIVE balance rate so that's a good place to start looking.

Congrats on EFI, Robs tunes have awesome reviews
 
I love Rob's tuning on my LMM, you won't be disappointed
 
Replaced #5 injector that was stuck and a week later #4 was stuck open. I'm doing the other 7 injectors this time. Although having injectors stick open and render the truck helpless is irritating to put it nicely. It's cost me alot of money in transporting and fuel because of these poorly designed injectors. I'm tempted to scrap this project, sell the performance stuff, and replace it with a Cummins powered truck. In 8 years my dinosaur 12v has never left me on the side of the road. Unfortunate though, since the Duramax is in such nice shape, no rust, and the crew cab is very convenient.
 
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Got the other 7 in. Truck runs very nice now and between the fresh injectors and readjusting the valves it's so smooth and quiet. We're going to keep the truck so I'm going to call up IdahoRob's place and get the tunes built. Not sure which to get since I've either run box tuners or screw driver pumps, but I'd rather get them once and be done with it. I'll likely never run bigger injectors or turbo, so basically a few tunes I can run with the stock transmission, then a couple I can enjoy once it's built.

Basically something like:

1. Optimized Stock [I'm guessing this would be considered Economy/tow heavy?]
2. Average towing [under 8,000lbs]
3. Daily Tune [90hp?]
4. Aggressive Tune [150ish]
5. Max effort for factory turbo/injectors [1/4 mile tune]
 
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Tuning choices look like a good fit. Give us a shout and we'll walk you through the options.
 
Thanks Rob. I'll call tomorrow unless work holds me over. Shall I ask for Rob or would Dustin [placed my order with] do?



Also I may need someone to walk me through sending in my factory tune or however you guys do that. I'm still pretty green with EFI live. It's there like a 'basics tasks' tutorial webpage or something?
 
I had Cody over there at ATP (good friend of mine) send me the autocal and DSP5 switch for my LMM, it was easy to install and set up. Done in about an hour start to finish. Best money I've ever spent on that truck.
 
Cody sounds familiar, I may have asked him a bunch of my EFInewb questions when I first considered buying the package. What tunes did you get Mr.T?

Not sure if I mentioned this but the truck was straight piped after #5 was replaced. K&N is supposedly sending me a new filter to replace mine which is dry rotted and I'll be doing gauges and a radio that plays those micro records next.
 
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First off I'd throw that K&N in the trash.

My tunes are an optimized stock, 30hp heavy tow, 60hp light tow, 90hp economy, and a 120 performance. I've got a 6 speed so the 120 won't hurt my stock trans.
 
The K&N was free and I figured a intake kit wasn't worth it for my modest "build". What's your suggestion?

Thinking out loud, but my ricer math shows your 90hp economy tune is like my 150hp aggressive tune. I sometimes forget how much more those LMM's made compared to mine from the factory.
 
The stock intake has shown to be just fine up to 500hp, so that's what I'd run. K&N's don't filter worth a schit. Hah
 
The saga continues. While I was putting in a new radio, my buddy ran some checks on a SES light I had. The SES was for rail pressure. We only had a few minutes to check it, but basically it was showing low rail pressure compared to what he was demanding with the Tech2. I think he was demanding 2x,000 at idle and it was only giving us 8,000-9,000. We've got to do some more diagnostics, but I think a CP3 replacement is in my future. Anyone got advice on where to buy those or if I should get a LBZ one like someone at the shop mentioned?

Might go without saying, but I have postponed getting any tunes built until we get these other bugs worked out.



I'm trying to keep high spirits while this truck is buttfuking my wallet, by looking at the price tags of 2014 diesels at the local dealership....
 
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Very Rare on a LB7 to have the FPRV leak.

Low rail pressure on LB7 is usually caused by supply issues/fuel filter, too high of return rate on injectors (can be tested), or weak CP3. I'd start with the inexpensive things first.
 
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