First road trip LMM HMMWV

Mogman

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May 3, 2020
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Well after chasing codes and low power for a few weeks I discovered I have a bad ECM, swapped out the one from my 1 ton dropped the tune for the HMMWV in it and she dang near got away from me in the driveway!
Took it for a 45 mile jog to Beeville to get the state inspection and it ran and drove GREAT!!!
So here are the numbers, not sure what would be ideal...
Water temp modulating between 186 and 192 deg
Trans temp modulating between 170 and 175 deg
EGTs at 70 PH (1800 RPM) 800 with 14 MPH tail wind, 900 with head wind, ambient 85 deg, EGT probe is between #5 and #7 exhaust port. with the head wind I could easily get it to 1000 deg while accelerating.
The oil pressure is much lower than I would like, fully warmed up she is running 35 PSI @ 1800 RPM and about 15 PSI at 720 RPM, (15W40 Rotella) the donor truck had 295K on it.
Inspection.jpg
EDIT actually the probe is pretty much right in front of the #7 cylinder
 
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TheBac

Why do I keep doing this?
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So this truck actually does exist.

Congrats on finally getting on the road.

Sent from my SM-G986U using Tapatalk
 

Mogman

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May 3, 2020
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It shifts a little "funny" unloads a little more than I care for between I think 2nd and 3rd but then again my LMM 1 ton shifts kinda weird compared to anything else I have ever driven, which is now sick with a defective ECM until I can get another one (may be here Friday!)
 

2004LB7

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There is a table in the tune for turbo vane position between shifts that may help. You will probably need to do some logging to find out where in the table it would need adjustment. I'm not at my computer to tell you what table number it is. Someone else may know or I can post it later today when I get home
 

Mogman

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May 3, 2020
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Papalote, TX
There is a table in the tune for turbo vane position between shifts that may help. You will probably need to do some logging to find out where in the table it would need adjustment. I'm not at my computer to tell you what table number it is. Someone else may know or I can post it later today when I get home
No doubt I have allot to learn, I did do some tuning as suggested to get as close to a "LB7 idle" as possible, maybe it influenced something else, it's not bad, I can live with it until I learn more, still a LONG way to go on this project, I have a shelter to install and outfit with radios and camping gear so it looks something close to this, one difference is I have supplemental armor hard doors.
HMMWV-Shelter-2.jpg

And also the Custom front end I built for #1 including bumper, (will probably be 8" instead of 6" because of the 2" body lift) brush guard and 12K hydraulic winch.
brush guard.jpg
I also will have to build a hard top for it, fortunately I have a guy In Corpus that did the brake work for the front end of #1 (bent the upright channel pieces and circumference brush guard piece) that is pretty awesome to help with that.
 
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2004LB7

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Dec 15, 2010
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There is a table in the tune for turbo vane position between shifts that may help. You will probably need to do some logging to find out where in the table it would need adjustment. I'm not at my computer to tell you what table number it is. Someone else may know or I can post it later today when I get home

found it. table B2242
 

Chevy1925

don't know sh!t about IFS
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mechanical gauge on the engine or going off the stock sender in the stock location on the block?
 

Mogman

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mechanical gauge on the engine or going off the stock sender in the stock location on the block?
Aftermarket gauge (programmable stepper motor gauge) going off of the 1/2" NPT plug on the oil filter adapter, I did not think to see if it was also on the live data I can see on my Autel
 

Chevy1925

don't know sh!t about IFS
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Aftermarket gauge (programmable stepper motor gauge) going off of the 1/2" NPT plug on the oil filter adapter, I did not think to see if it was also on the live data I can see on my Autel

ah, going off oil filter adapter would make that sound very low being oil has not hit any mains or rods yet. 03 and up have it on the 2nd from the back oil galley plug which would show even lower oil pressure than what you are seeing. id make sure that gauge is programmed right
 

Mogman

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May 3, 2020
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Papalote, TX
ah, going off oil filter adapter would make that sound very low being oil has not hit any mains or rods yet. 03 and up have it on the 2nd from the back oil galley plug which would show even lower oil pressure than what you are seeing. id make sure that gauge is programmed right
I am assuming it is close but will need to confirm, the sending unit also has a 20PSI switch in it for a light and the light flickers at temp when idling, large difference between cold and hot, cold it runs about 50PSI at idle and about 100PSI revved up
 

Chevy1925

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based on your pressures you posted, you are at or below GM spec for oil pressure at temp. factory rating is 14psi at idle when hot and 38psi at 1800rpm. if the light is flickering at 20psi, thats much closer to typical oil pressure at idle when hot.
 

Mogman

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based on your pressures you posted, you are at or below GM spec for oil pressure at temp. factory rating is 14psi at idle when hot and 38psi at 1800rpm. if the light is flickering at 20psi, thats much closer to typical oil pressure at idle when hot.
Well I guess for 290K + that is not too bad, I need to confirm I used 15-40 otherwise I do not know of any thicker oil approved for turbo diesels.
 

Chevy1925

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Well I guess for 290K + that is not too bad, I need to confirm I used 15-40 otherwise I do not know of any thicker oil approved for turbo diesels.

i think id confirm that gauge first. be surprised how many engines with 300k on them are still holding great oil pressure.
 

2004LB7

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If it is infact low, you can always put a bit of Delo 20w50 in it. Not a solution but may buy you some more time before a rebuild or another engine

James didn't you run a blend with 20w50 in your older rig to keep the oil pressure up in hot weather?
 

Mogman

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It will take me a long time to put 20K or so on this truck, well that is based on my #1 Humvee which has the anemic 6.2L so that may change....
 

Chevy1925

don't know sh!t about IFS
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If it is infact low, you can always put a bit of Delo 20w50 in it. Not a solution but may buy you some more time before a rebuild or another engine

James didn't you run a blend with 20w50 in your older rig to keep the oil pressure up in hot weather?

i ran 20w50 for the protection the cenpeco oil offered over off the shelf stuff. it doesnt help in hot weather as it gets hotter faster, thins out and then winds up doing the same thing as 15w40 but at a hotter temp UNLESS you have the cooling to get that heat out which is where the oil cooler and external one i had helped mitigate that.
 

Mogman

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Took her for a 100mi jog this morning, what a hoot to drive!! so much more relaxing driving at 2000RPM rather than 3000RPM.
Saw my propane guy ahead on the way home, was pleasantly surprised at how easily she popped up to 95 to "ambush" him!
I am sure he will go home and tell dad about being blown off the road by a Humvee LOL.