1999f1504x4

My dads 04 superduty absolutely runs terrible until about 10-15 min of solid driving. The truck wont shift until like 3 thousand rpm and then even still u gotta let off the gas to get it to shift. Its starts poor too. When u hold ur foot to the floor while starting it seems to help a bit but not much. Umm it chuggs like nothing ive ever seen trying to maintain/accelerate the slightest bit. All of this is only til the truck gets real nice and warm and then it drives like a dream. Just thought someone here might know whats goin on in there.

My thoughts were fuel pumo somehow? Cause its not like a constant dead miss from the same spot and it doesnt do it later on.

Truck is a 6.0 diesel 4x4 dually fx4

Any help is appreciated.
Thanks

bcangelo

check glow plugs and gp relays. They stay on even after the light goes off up and stay on util the trucks warms up. Any white/blueish smoke?

1999f1504x4

Ok umm any chance on throwin me some pointers on how to check that stuff. Truck is sitting at the house all this week not moving so it would be the best time to check it out.

Thanks for responding

1999f1504x4

Oh and this truck almost never blows any colour of smoke what so ever.

Thanks again.

05 4x4 Triton

I would doubt the fuel pump if it stops when it warms up, like bcangelo said check the glow plugs I'm not sure if it is or not but it sounds like you may have some injector problems but once again that doesn't explain it if it stops once the truck warms up good luck with the fix and that 6.0 lol

bcangelo

6.0s are bad about eating injectors and when they are cold it will be more noticeable. If anyone you know has access to auto enginuity usually refered to as AE, you can do a buzz test on the injectors and contribution test to check for weak points. You can use a volt meter and check the relay switch.

lddrew

best advice - trade it in.

second best- sounds like injectors took a ****. which is a common and expensive problem on these. lift the cab. do injectors, all the deletes, and headstuds. run some aftermarket 2 micron fuel filtration and change your oil religiously

broncof250444

You have either some bad injectors or your FICM module it putting out low voltage to the injector which will make it look like faulty injectors. Check dtc's if a scanner or run by autozone, etc for a free scan and get the dtcs.

Eleven-eco

Im going with injectors. How cold is it where you are anyways?

1999f1504x4

Its not cold but even at 0 degrees celsius unless its plugged in its brutal to start and runs very bad for atleast 15 minutes while driving.