2004 2500HD gas reduced engine power?

tylertown · Jan 17, 2014

hi i am having some trouble with my 6.0 2500hd

no problems with the truck at all. runs great but yesterday i left home maybe 3 miles down the road it said reduced engine power and could hardly accelerate. i shut it off and started back up. went about another 2 miles before it did it again. leaving work no problems until the next morning
it did it again.

but when i pulled my machine roughly 12k trailer and all i had no problems. acts like it never happend. and pulling about 3 to 4k rpm. what could cause this to happen at low rpm running 40mph?

any input is greatly appreciated!!

Tx Jim · Jan 18, 2014

How long since fuel filter was changed??

wthompson · Jan 18, 2014

Have you tried cleaning the throttle body? Here's a video Part 1 Cleaning LS Throttle Body | Vortec 4.8 5.3 6.0 6.2 Liter - YouTube.

I don't think they have a fuel filter.

Illini22 · Jan 18, 2014

I have the same truck. The fuel filter is in the tank, I believe it's before the fuel pump. I believe the thinking was that by having the filter before the pump rather than after (like the earlier models) the pump wouldn't have to work as hard. I have 132,000 miles with no issues (yet).
Could it also be one of the coil packs?

tylertown · Jan 18, 2014

Tx Jim said:
How long since fuel filter was changed??

it doesn't have a in-line fuel filter the only filtering it has the sock on the fuel pump it self in the tank..

tylertown · Jan 18, 2014

Illini22 said:
I have the same truck. The fuel filter is in the tank, I believe it's before the fuel pump. I believe the thinking was that by having the filter before the pump rather than after (like the earlier models) the pump wouldn't have to work as hard. I have 132,000 miles with no issues (yet).
Could it also be one of the coil packs?

They are fine trucks I really like mine. but this problem has me scratching my head. the reduced engine power things comes on without any kind of syncranization it comes on at low rpm cruising speeds not to familiar with electronics but I do know that a sensor of some sort could cause this but have no idea where to start. those low end code readers at the auto parts house don't pin point anything. someone told me that it could be the igniton or the "brain box" but those answers don't seem logical to me because if the thing is cranked and running ignition is out of the picture

but the computer may be bad but I have heard of a few people who have replaced the computer in a few different model trucks and never fixes the initial problem. I don't know where to start. maybe the more it does it I can pin point some type of diagnosis question but this is all I have got right now..

kham0315 · Jan 18, 2014

You need to scan for dtc's. this is usually caused by the throttle body and/or the connector that plugs into it. There is an extended warranty on some vehicles.

tylertown · Jan 19, 2014

kham0315 said:
You need to scan for dtc's. this is usually caused by the throttle body and/or the connector that plugs into it. There is an extended warranty on some vehicles.

thanks I scanned it and it came up with a problem with throttle body actuator

kham0315 · Jan 20, 2014

If you got one or more of these dtc's p0120,p0220,p1516,p2101,p2135 there is a bulletin to replace connector pigtail at throttle body.I would start there. Cheaper than a throttle body.Connector must be soldered and shrink wrap. no but connectors!

tylertown · Jan 20, 2014

kham0315 said:
If you got one or more of these dtc's p0120,p0220,p1516,p2101,p2135 there is a bulletin to replace connector pigtail at throttle body.I would start there. Cheaper than a throttle body.Connector must be soldered and shrink wrap. no but connectors!

thanks! cause I would've of sure used connectors! haha thanks im going to look into the pig tail today!