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Impossible to find cold weather issue

1372 Views 14 Replies 6 Participants Last post by  01_Cummins_H.O.
Hey, been a while since i tried to diagnose this problem, but with local temps around here in uptsate NY getting to about 10 at best, my problem has come back.

I got an 01 cummins HO, 6spd, SBDD, AFE intake, ATS mani, Airdog 2 165, DDP75's (right now) but will have bigger sticks in this summer, and a Smarty.

My problem is I can start the truck up but after about 5 mins (whether plugged in or not) the truck idle starts bouncing, hunting for fuel i think? The other day i drained my filters in my heated garage n found about 1oz of blue gelly stuff (guess it was cold!), but everything else was fine no gel issues, and from what i can tell the w/s filter is still working well (just changed them this past summer). Im wondering if perhaps my smarty being set on 5 is too high for the winter. Idk if I should just turn it down to 1 or take it off. Seems to be the only thing i have yet to try, but that seems a little weird to me that the smarty would be causing my hunting idle issue.

If im driving down the road i have good fuel pressure (12-15), good boost, and the pyro is low, but if i drop the hammer the truck bucks a little, like a burp of fuel goes by and it barks at me (for just a split second). If i come to a stop it hunts for idle and will bounce and almost stall before catching itself, so i end up having to keep one foot on the brake, the other on the gas and rev it to about 1200 so i dont stall in an intersection (quite a hard switch from brake to clutch on hill starts!). If the truck does die, i have to pop the hood, and bleed the fuel lines to get fuel back into the engine, and then get going down the road after apologizing to several cars about y i didnt move when the light turned.

Either way, if you managed to read all this, you must be able to tell me where to look and what to check for, and perhaps if my smarty is causing my issue or not. Thanks.
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okay... heated garage... is the truck parked in there?? or parked outside??

I'm thinking that you might actually have something going on inside the VP. I read elsewhere (and I don't know this to be a fact, so help me out MoparMan) that there is a temp sensor inside of the VP44. IF that temp sensor is bad, could it be giving an incorrect throttling for the temperature, but not be "off" enough to set a code inside either brain??

In my mind, it runs well when warmer, the fuel isn't gelled and is making it to the VP44, you've got an internal issue with the VP44, or one of the sensors that controls the VP44. Extreme cold (and heat) can make electronics do wonky things.

A solder joint that's pulled apart when things contract causing the issue? Sensor not quite right? Connector that's contracted just enough to allow intermittent contact?

I think I'd start with checking all connections, but I'd be willing to put money on it being something on the inside of the VP electronics.
If you do...get the TIMBO's a lot better... I have one on my truck. Was hoping that would cure my dead's gonna be a new VP44 to cure that...Got one sitting on the shelf waiting for install.
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