2007 GMC Denali stalls after towing

[upnorth76]

Yes I meant the GMT900 platform. I’m a Dodge guy and I only drive GM because Dodge doesn’t make a vehicle that is suitable for my needs.


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[Hank Schlesinger]

Jeff, I have the same problem I was going to try the insulation, anything special was the insulation you used? a wrap type? WHere did you purchase the insulation? I tried checking my fuel pressure but the Schrader valve must be bad I get zero fuel pressure

 

[oldtimer]

I used Thermaflect tape (see post #69) to insulate fuel rails.
Still chasing problem. I will try 15-50wt oil next. Maybe a hot oil, low pressure issue??????

https://www.amazon.com/gp/product/B000QFN3DU/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1

 

[JEFFC]

Jeff, I have the same problem I was going to try the insulation, anything special was the insulation you used? a wrap type? WHere did you purchase the insulation? I tried checking my fuel pressure but the Schrader valve must be bad I get zero fuel pressure

I would get the pressure test and bleed off figured out before proceeding just to verify that your problem is the same as mine was. I have had several members message me back that this was in fact their problem. Verify by performing the fuel bleed via a few key cycles. No reason to wrap the lines and fuel rail manifold if bleeding the fuel doesn't allow it to start instantly. Refer back to post 14 for the materials and here is a link for the 3/4 inch wrap that I used on the lines. I don't see the 1 1/2 inch listed now but any of the larger sizes should work since you will be doing a lot of cutting and zip tying around the fuel rail manifolds.
3 feet Fire Sleeve Braid Flame Heat Shield 3/4" Fits 10AN for Oil Fuel Lines Red | eBay

 

[Cincikid]

I signed up here after googling this issue, I'm experiencing the same issue when towing a 4000lb camper. Has anyone found a sure solution? Does anyone agree with the guy above to replace the PCB?

 

[Doubeleive]

I signed up here after googling this issue, I'm experiencing the same issue when towing a 4000lb camper. Has anyone found a sure solution? Does anyone agree with the guy above to replace the PCB?

I directed you over here, all I can add is to try the fuel line pressure release first since that will not cost you anything to try, I don't think it is a common enough issue for anyone to say "yes" this for sure works, it could be any of the above or something else entirely, if you have the time and money to throw at it maybe shotgun it and try them all?

 

[wesyder]

Does anyone with an aftermarket trans cooler still have the stalling issue, I put a truecool 40k on my 05 and my 08 and neither have stalled since


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[HD_LS]

I signed up here after googling this issue, I'm experiencing the same issue when towing a 4000lb camper. Has anyone found a sure solution? Does anyone agree with the guy above to replace the PCB?

What vehicle do you have? 2007-2008 6.2L? If so, no sure solution, since there are a number of potential causes ... but the low hot oil pressure/VVT problem is probably the cause 80% of the time. So the very first thing you should do is check what your oil pressure is at idle, when the engine is fully hot (better yet, after towing). You may need a scan tool that is capable of displaying oil pressure. Anything less than 20 PSI at hot idle may be a problem.

 

[wesyder]

The bigger to question to that would be what were your transmission temperatures before and after, I don't think a overheated transmission would prevent the vehicle from starting it would say the transmission is hot and that's about it.

IMO trans heat combined with catalytic converter heat would contribute to vapor lock, my trans temp would go 3/4 of the way towing not necessarily over heating the trans, but since the upgrade trans temps don’t go past half and i don’t stall anymore


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[Doubeleive]

IMO trans heat combined with catalytic converter heat would contribute to vapor lock, my trans temp would go 3/4 of the way towing not necessarily over heating the trans, but since the upgrade trans temps don’t go past half and i don’t stall anymore


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there is no 3/4 of the way on the gmt900's only degree's
mine would easily be 210-220 all the time just driving, albeit I drive like a madman, but once I added the tru-cool and a B&M deep pan it has not gone over 180 and usually hangs around 145-165 or less in the winter, trans lines & oil lines run separate from each other completely and run on opposite sides of the radiator.