Truck do random CHUG , HELP!!!
 

Since last week my truck start to CHUG when I drive it at any speed, it look like the transmission shift for no reason and send a signal to the engine to drop rpm. If I put the transmission on neutral I get the full rpm but as soon I put it back to drive it start to chug. I clean the conectors on the transmissiom and on the conector where the gas pedal sensor is and put dielectric on the conector, I found nothing wrong there out of some oil in one conector. The transmission fluid is good. Last night I make the truck sleep in the garage, this morning it was working fine, but after work on my way back home it start again, we have some snow here and the first time it start to do it it was raining, but some raining day it dont do it, so I dont think that wheather have something to do with it, My truck is a 2004 with a AirDog 150, everything else is stock.

Sounds like a fuel pressure problem. When was the last time you changed the fuel filter and serviced the water/fuel separator?

At the begining of the summer, I think about that but why my transmission will shift like that, I have brand new set of filter in my garage, I will try that.

I change my two filter, I drain the old one and a bit of water was in the water separator. I drive the truck to work and for now it's fine. Give you some news further this week.

Truck is fine, no problem since I change the filter. Still on test drive for a bit...

My truck start to chug again today, it was fine for a week. No code show up, today it's
- 15 and snow fall. I have no clue where to start to check for that snag...

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Tonight after diner I drive my truck and I beat the crap out of it and it drive like new. I do a lot of stop and go, drive it in tow/haul mode, in drive, 2 and 1 speed selection, nothing happen. This truck is pising me off right now. I see on other tread that some guy have problem with a selenoid in the transmission, I dont now if this is my problem, a bad selenoid, if somebody have any advice, help is welcome.

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My truck pup a code today, P0720 (Output speed sensor circuit malfunction) I dont no what is that system and if that have something to do with my problem. If somebody already have that code, what I have to check to troubleshoot...

Yesterday I change my speed sensor, 36.00$, Test drive the truck for a couple of day an I comeback with the result...