random stalling.no code.
 

ive got a 2003 2500 diesel with 140000 miles on it. its an auto with a brand new tranny. and it was stalling randomly a few months ago, and eventually wouldnt start. it threw a code p0628 so i replaced the liftpump. now, a few thousand miles later, its doing the same thing. but this time, no code. it stalls once a week about while im at hiway speeds. but i just coast for a few seconds, and it fires right back up, i dont even need to stop. the fuel filter was new when i did the liftpump. any suggestions? i dont want to get stuck somewhere since im working this truck daily. thanks.

Do you have a scan tools you can hook up and see the data stream while driving? I am going to assume not but if you do use it to see key data.

IMHO I would get a fuel pressure gauge so you can monitor what your fuel pressure is before, during and after the stalling happens. This would partially eliminate a lift pump issue. If you good pressure when it stalls then it isn't the lift pump. If it does lose pressure before and when it stalls then you have a pump issue or electrical to the pump issue.

There are several fuel pressure gauges available from Autometer, Di Pricol and Isspro. I got mine from Diesel Manor but many also buy from Geno's Garage and other companies.

i have the quadzilla xillarator with a rail pressure guage. and it never drops off. when it stalls, its usually around 1900 psi.

While it is good you have rail pressure when it dies that is an indication you have some supply pressure...however rail pressure and the supply pressure are 2 different things. I would still put a fuel pressure gauge on it and make sure you have supply pressure (factory is roughly 7psi and if your running an aftermarket lift pump roughly 20psi or so) If the supply pressure is low then it will stall. I would think your rail pressure would drop off as well but it may be more instantaneous...if you check supply pressure and it is low then it may be the cause.

Again I am not saying this is definitely the cause but one thing to eliminate. The other thing you may want to check is the wire for the AC pressure switch where it crosses the ac lines under the oil filter. These trucks have had a tendency to chafe this wire on the ac fitting and short out intermittently causing all kinds of weird problems ranging from stalling to weird codes. There is a separate thread on this as a sticky near the top of one of the 3rd gen sections.

uh, mine will do that occasionally. my quad, with rp gauge is causing it. does your rail pressure lock up(meaning reading not changing) ? my truck only does this when the quad is installed. just requires me to turn off the truck, wait until the rail gauge goes blank, and then a restart.
call quad, they probably will swap out your equipment.