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2004 Yukon XL 2500 LBZ

Will L.

Well-Known Member
Messages
8,660
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8,453
Location
Boulder City Nv
Yeah, last one I did on my friends truck there was no signs of leaking. But the pump it up scenario when he called I said just order the kit. Helped him swap in the kit and no more issue.

Usually there is at least a little dirty spot where the fuel collects dust, but his was clean. Sucking air when off somehow was my guess.
 

BigDogYJ

Active Member
Messages
422
Likes
172
Location
Kommifornia
Stock without a lift pump the filter head will be dry because it is sucking air in since the fuel system runs under vacuum. With a lift pump you almost always get a fuel leak thats visible since the fuel system now runs under positive pressure.
Hmmm. That’s what I thought. So there’s no sign of leakage at the filter head or at the soft lines coming off the filter head. Strange thing is after the two times it acted up it hasn’t happened since.
I’m wondering if it somehow was caused by the 1/8th tank of fuel and being parked on a slight incline before parking that night?? I ordered the MA rebuild kit so I have it in case I need it. I’ll keep driving it and see if it acts up anymore.
My understanding is that the Fass pump is a flow thru design since the truck runs fine if I pull the fuse for the Fass. So if I was low on fuel and on a slant, and the bottom of the pickup tube wasn’t submerged could the fuel in the line drain back? I can’t see that happening but maybe it’s possible.

When it happened the first time it didn’t even try and fire just cranked like there was no fuel. Then it finally fired up after the 4th or 5th attempt. I Shut it down 15 mins later to get fuel and first crank took an extra second or so but it started up on the first attempt.

Just strange. That’s all. Thanks for the input guys.
 

BigDogYJ

Active Member
Messages
422
Likes
172
Location
Kommifornia
California allows the swap as long as all the original emissions equipment is installed that came with the engine. And the engine has to be from the same model year or newer. Then it gets inspected at the smog referee station. Once that’s done it’s all legal. Then I transfer my reg to a different county that doesn’t require bi-annual smog inspections.
So it’s all legal. Last friday I got it inspected by the smog referee and they issued a BAR label which basically approves the engine change and the vehicle can now be emissions tested as if it were a 2006 2500HD with the LBZ, and it’s all legal.
Haven’t put too many miles on it lately just a lot of around town driving. MPG seems to hover around 15-16 around town. We’ve got some trips coming up in a few months and I can’t wait to get it back out on the road.
 

BigDogYJ

Active Member
Messages
422
Likes
172
Location
Kommifornia
Hmmm. That’s what I thought. So there’s no sign of leakage at the filter head or at the soft lines coming off the filter head. Strange thing is after the two times it acted up it hasn’t happened since.
I’m wondering if it somehow was caused by the 1/8th tank of fuel and being parked on a slight incline before parking that night?? I ordered the MA rebuild kit so I have it in case I need it. I’ll keep driving it and see if it acts up anymore.
My understanding is that the Fass pump is a flow thru design since the truck runs fine if I pull the fuse for the Fass. So if I was low on fuel and on a slant, and the bottom of the pickup tube wasn’t submerged could the fuel in the line drain back? I can’t see that happening but maybe it’s possible.

When it happened the first time it didn’t even try and fire just cranked like there was no fuel. Then it finally fired up after the 4th or 5th attempt. I Shut it down 15 mins later to get fuel and first crank took an extra second or so but it started up on the first attempt.

Just strange. That’s all. Thanks for the input guys.
To follow up with this, I haven’t changed anything just filled it up with fuel and it hasn’t had an issue since. Must have just been the angle we were parked and the low amount of fuel in the tank. I ordered the filter head rebuild kit from merchant and replacement soft lines just so I have them.
 

BigDogYJ

Active Member
Messages
422
Likes
172
Location
Kommifornia
Hey guys. It’s been a while but still driving this rig. We are currently in Island Park, ID. Ran into a few issues the past couple days. I am just guessing but could be because this truck has never experienced cold like we have experienced the past few days. Sorry its a little long.

The other morning I went to start it and it was not plugged in overnight. Overnight low 17F.
Went to crank and died. Cranked again and died. Shut it off waited a minute. Tried again, cranked and died. Tried one more time with foot on throttle and it fired up a little rough and there was some injector rattle but otherwise idled fine. I chalked it up to not plugging it in overnight and not running a winter additive in the fuel (shame on me). I immediately added some stanadyne winter 1000 and topped off the tank and it seem to run ok (definitely louder) but power was there, no smoke. Drove it for another 250 miles or so without issue.
Last night I plugged it in overnight and this morning fired up like a champ. Still seemed to have some injector noise under heavy throttle. Then this afternoon it behaved the same way that it did the other morning. IT would crank and die immediately. I know it wasn’t cold temp related (or at least cold overnight temps). It took a lot more work to get it started but once I did CEL was on. I got P2510 and P0120 (more on these below). After running it this evening and getting it all warmed up, I gave it good run from about 45mph to 80mph and when hammering the throttle, there was some serious injector knock for a second or so then it went a way pulled pretty strong. Second run injector knock was not as bad but definitely seems louder than normal (at least what I know about this truck).


P2510 - ECM/PCM Power Relay Sense Circuit Performance:
I assume this has to do with the relay added to control the ECM Power up. I checked the wiring in the fuse box slots and its tight. I’ll need to pull the fusebox up and check the relay and other wiring underneath there.
If nothing looks out of place, I’ll put a call into Eric @ DuraBurb to see what he has to say. We are planning to head to Keystone, SD tomorrow.

P0120 - MAF Sensor Circuit Low Frequency:
I am running a stock air intake box and filter — no mods there. I know the MAF is clean because I just cleaned it during my normal maintenance routine before leaving town last week. Might have just been a fluke with the irractic starting issue mentioned above.

If you have any insight I’m all ears. I plan to check the wiring for relay in the AM and check MAF wiring.
Thanks all.
 

BigDogYJ

Active Member
Messages
422
Likes
172
Location
Kommifornia
Hey guys. It’s been a while but still driving this rig. We are currently in Island Park, ID. Ran into a few issues the past couple days. I am just guessing but could be because this truck has never experienced cold like we have experienced the past few days. Sorry its a little long.

The other morning I went to start it and it was not plugged in overnight. Overnight low 17F.
Went to crank and died. Cranked again and died. Shut it off waited a minute. Tried again, cranked and died. Tried one more time with foot on throttle and it fired up a little rough and there was some injector rattle but otherwise idled fine. I chalked it up to not plugging it in overnight and not running a winter additive in the fuel (shame on me). I immediately added some stanadyne winter 1000 and topped off the tank and it seem to run ok (definitely louder) but power was there, no smoke. Drove it for another 250 miles or so without issue.
Last night I plugged it in overnight and this morning fired up like a champ. Still seemed to have some injector noise under heavy throttle. Then this afternoon it behaved the same way that it did the other morning. IT would crank and die immediately. I know it wasn’t cold temp related (or at least cold overnight temps). It took a lot more work to get it started but once I did CEL was on. I got P2510 and P0120 (more on these below). After running it this evening and getting it all warmed up, I gave it good run from about 45mph to 80mph and when hammering the throttle, there was some serious injector knock for a second or so then it went a way pulled pretty strong. Second run injector knock was not as bad but definitely seems louder than normal (at least what I know about this truck).


P2510 - ECM/PCM Power Relay Sense Circuit Performance:
I assume this has to do with the relay added to control the ECM Power up. I checked the wiring in the fuse box slots and its tight. I’ll need to pull the fusebox up and check the relay and other wiring underneath there.
If nothing looks out of place, I’ll put a call into Eric @ DuraBurb to see what he has to say. We are planning to head to Keystone, SD tomorrow.

P0120 - MAF Sensor Circuit Low Frequency:
I am running a stock air intake box and filter — no mods there. I know the MAF is clean because I just cleaned it during my normal maintenance routine before leaving town last week. Might have just been a fluke with the irractic starting issue mentioned above.

If you have any insight I’m all ears. I plan to check the wiring for relay in the AM and check MAF wiring.
Thanks all.
UPDATE:
So last night it was down to about 10F and I had it plugged in. Before firing it up this morning I tuned it back to stock (I was running an Econ tune from Ferm). I also found the intake resonator was loose. I tightened up the clamps on that so that was probably my P0120 code. I noticed that when I turned the key on I didn’t see a wait to start light. So I waited about 30 seconds and fired it up and it started without issue. I put about 250 miles on it so far today and no codes or issues starting as long as I wait about 10-15 seconds before cranking. Also the injector rattle or injector knock has almost gone away completely. There’s still some noise but nothing like it was last night. I picked up another bottle Stanadyne and will run that in the next tank. Maybe the Econ tune just isn’t happy with the cold weather we’ve been in. I’ll keep ya updated.
Thanks.
 

btfarm

335,000 Worth and counting
Staff member
Lead Moderator
Messages
16,919
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3,000
Location
Sandwich, Illinois
They always get alot more loud in very cold weather. I also learned long ago that any time the temp is below freezing to never hammer the throttle or it will make you pay by limping. Above freezing isn't a problem.
 
Last edited:

BigDogYJ

Active Member
Messages
422
Likes
172
Location
Kommifornia
They always get alot more loud in very cold weather. I also learned long ago that any time the temp is below freezing to never hammer the throttle or it with make you pay by limping. Above freezing isn't a problem.
Yeah definitely louder in the colder temps. Yesterday was a high of 30F. Today temps ranged from 35-55. Ran pretty normal today (~650 miles). Still averaging around 20mpg. Added that bottle of stanadyne still have a slight noise but I might be super sensitive right now. I’ll keep an eye on it. Still got about 1800 miles to go till we get back home.

If your curious here is current planned route (currently in SD, headed to CO tomorrow): B349B70E-6A2D-4E09-BAD4-84D7FC42266C.jpeg
 

Husker6.5

135' diagonal 16:9HD, 25KW sound!
Messages
1,854
Likes
1,365
Location
Lincoln, NE
May I suggest, since you appear to he in Rapid City, that you just stay on US 385 south of Hot Springs instead of swinging west on US 18. You'll get to see some beautiful country as you drop down through the Buffalo Gap National Grassland and into the Pine Ridge area around Chadron and the Nebraska National Forest. When you hit just north of Alliance, it is more than worth the 3 mile cut over to NE 87 to see Carhenge, which was one of the best places to watch the total eclipse of the Sun in the US a year ago for both duration and clearness of the sky. I was there, along with nearly 15,000 people from all over the US, Canada and Central and South America to watch it. Keep going south on 385 as it skirts the western edge of the Nebraska Sandhills, then cut over NE L62A and drop south on US 26 thru Bayard, cross the North Platte River and stop at the most famous and iconic landmark along the Oregon, California, Mormon and Pony Express Trails, Chimney Rock. Continue down US 26 to Bridgeport and catch 385 south to Sidney, NE - founding home of the famous outfitter, Cabela's (recently acquired by Bass Pro Shop :mad:). Then drop south on NE 19/CO 113 into Sterling, CO and catch I-76 into Denver. A little bit longer distance and a couple of hours more time than I-25, but well worth it and quite doable in a short day of driving.

Unless of course your "tomorrow" when you posted at 2:41am today is actually today, in which case it's too late and nevermind.

As for your cold start problem that was resolved when you re-installed the factory tune, often times (and I'm saying this without knowing the details of Ferm's Economy Tune) an economy tune will advance the injection timing some to increase combustion efficiency - the downside being that doing so often makes cold starts harder (cold being up here cold, not Florida "cold") and the resultant injector clatter can be disconcerting if you've never experienced it before, you think you have an injector issue when it's actually due to the earlier combustion while cold.
 

THEFERMANATOR

FRANKENBURBAN
Staff member
Lead Moderator
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2,927
Location
ZEPHYRHILLS FL
Were you running the econ tune out of my dsp5? There was alot of changes in that tune and it was really meant for a dsp5. And the noise will go up as it runs ALOT of timing, that was the bulk of how it bumped mpg's. I know I have sent that tune in dsp5 format to people who have used it in Alaska without issue, so I'm not sure which version you got of it.
 

BigDogYJ

Active Member
Messages
422
Likes
172
Location
Kommifornia
Sorry for not getting back and updating here. We made it home then ended up buying a house and then had to paint and do some work to it. Then we just moved in this past Saturday. Funny how things start snowballing.

Anyways, we made it home with the truck acting up at startup a few more times. But now that we’ve been home for over a month, it hasn’t done it since (and we’ve made a couple 3-5 hour trips without issue). I bought an ignition switch and keep it in the truck in the event that ends up being the culprit.

@Husker6.5 - Thanks for all the travel tips, we were under a time crunch to get home this trip with the whole house thing. I’ll keep this info so the next time we are in the area, we’ll be checking it out. It was a beautiful trip.

@THEFERMANATOR - It was the Econ tune from the DSP5, it runs great around home in relative moderate temperatures. But yeah it wasn’t too happy up in the colder climates. I have been running the stock tune since then and haven’t had any issues.

So for now, I’m just waiting for it to act up so I can do some more troubleshooting.

Happy Thanksgiving everyone.
 

THEFERMANATOR

FRANKENBURBAN
Staff member
Lead Moderator
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2,927
Location
ZEPHYRHILLS FL
I know my 1st version of it had problems below 40 defrees when the engine was cold. Unfortunately to maximize economy, you have to push timing up and drop boost, this combo in cold air temps doesn't sound good. And without knowing how you pulled the 1 tune out, there may have been problems there. I know I've sent that dsp5 in lbz and lmm format to over a dozen people, and so far I haven't heard any problems about it when installed as I built it as a dsp5 other than the 1st truck I put it in saying it rattled when cold.
 

THEFERMANATOR

FRANKENBURBAN
Staff member
Lead Moderator
Messages
9,340
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2,927
Location
ZEPHYRHILLS FL
I know if you use a stock tune file, change the tables from the dsp5 that are different and only the dsp tables without the base tables, it will rattle something fierce on that econ tune. I ended up reducing the timing modifier tables to try and get all the tunes to play semi well in all conditions. When you're trying to write 5 conpletely different tunes, but only have access to about a dozen tables of a 1000, there is only so much you can do to make each one perfect in all conditions.
 
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