No engine power

[motormayhem]

After believing my tranny was shot I just drove it again and I think it may not be the tranny. I seems to be more a case of having/not having engine power. It will be fine, but when I hit a hill or incline the motor bogs down and I have to floor it. Then it will intermittently have a burst of power and accelerate then it looses this power and slows to about 30. Could this be a sign of bad gas, a fuel filter, or something else simple or am I gonna have to spend the big bucks?. In which case it will be going into hibernation. It seems to be fine in 1st, although a little hesitant at the point right before shifting into 2nd. I also could see in my mirror that when it had power I could see a light grey smoke in the headlights behind me (I have noticed this when I am driving normally, but the smoke stops when I loose power).

 

[Westech]

well start first at the fuel and air filter. Could be a pick up pump going to snot or a main Injection pump. With out seeing the truck it is hard to tell. But start with the cheap EZ fix and work your way up.

 

[dependable]

My first guess would be a air leak in fuel system. Lots of good info on older threads. Also check fuel delivery from lift pump . if not those then it might be the injector pump, which is a 4 to 7 hundred $ part and a bit of work.

 

[motormayhem]

How would I go about checking the pickup pump or for an air leak? Also could using ultra low sulfer gas do it or is that sold every where (I just noticed the sign at the last place I filled up at yesterday).

 

[appalacious]

That stuff is sold everywhere, but that don't make it right.
I'd get some sulfur additive at the parts store and put it in the tank.
Or better yet, run some 5% or 20% biodiesel. "they" say that even 3% biodiesel puts twice as much lubricity into the fuel than even the sulfur diesel of yesteryear. Just don't run straight Bio-d in this cold weather.
J

 

[motormayhem]

Also are the civilian pumps and filter the same.

 

[Crash_AF]

My 83 Burban was doing the same thing, cut in and out and all kids of junk... the fuel pump was failing. Put a new one on and no problems since.

Yes, the Civvie pump and filter are the same.

And it's not sulfur additive... it's lubricity additive... the process to remove the sulfur strips the lubricating properties out of the fuel.

Later,
Joe

 

[motormayhem]

How can I check the pump? Also does it make sense that it starts and runs fine in 1st and rev?

 

[Crash_AF]

Well, you can pull the outlet line and put it in a bucket, measure how much fuel it pumps out in a minute while cranking.

The only thing I can figure is it's starving for fuel under load. 1st and reverse have deeper gears so it doesn't load the engine as much as 2/3.

Later,
Joe

 

[motormayhem]

Yayyyyyyy! I took the old fuel filter off and a nice little stream of gray/ brown diesel came out of the drain hole. Got a new one and fired right up and chugged up a hill doing 35. Much better than the 5 and stalling it was doing before.

 

[scottc]

Glad to here you got it going

 

[4x4 Forever]

Water in Fuel?

Brown/Grey diesel is not good. Usually means you have had or do have water in the fuel tank or system.