1997 2500 4x4 with 430000 miles low power, especially noticeable going up hills

[ranger71]

So I've had this truck 18 years. Last year I had an issue with clouds of white smoke while driving. I replaced the cylinder head gasket and problem solved. Ran great for a couple of months but have noticed a decline in power the last few months, no smoke issues, just low power, like sluggish going up hills. Flat roads are no problem, revs rise and the turbo spools up and I'm happy but hit a light at the bottom of a long hill and I'm in trouble. Just cleaned the pre-filter screen in ultrasonic and no real difference but I'm happy I took the time as it was a little crusty after all these years. Any ideas guys? Lift pump is the one I bought with the truck back in 2000.... All ideas welcome. In diagnosing the cylinder head gasket I had the injectors tested and they were ok, not brilliant but not too far out of spec. What are your thoughts? lift pump? That return line spring thing on the injector pump? My truck still gets me to work but it needs help and the local diesel shop is a money pit with bad reviews... Please help!

 

[ranger71]

So I've had this truck 18 years. Last year I had an issue with clouds of white smoke while driving. I replaced the cylinder head gasket and problem solved. Ran great for a couple of months but have noticed a decline in power the last few months, no smoke issues, just low power, like sluggish going up hills. Flat roads are no problem, revs rise and the turbo spools up and I'm happy but hit a light at the bottom of a long hill and I'm in trouble. Just cleaned the pre-filter screen in ultrasonic and no real difference but I'm happy I took the time as it was a little crusty after all these years. Any ideas guys? Lift pump is the one I bought with the truck back in 2000.... All ideas welcome. In diagnosing the cylinder head gasket I had the injectors tested and they were ok, not brilliant but not too far out of spec. What are your thoughts? lift pump? That return line spring thing on the injector pump? My truck still gets me to work but it needs help and the local diesel shop is a money pit with bad reviews... Please help!

Just wanted to add that essentially it won't accelerate going up hills, under load, pretty sure the same thing would present if I was pulling a trailer. Once the load decreases like the road flattens out or going down a hill the motor revs rise and speed picks up, no smoke issues, downshifting will raise the revs but it feels like it is restricted, like it pulls but only to a certain point then it just hits a wall.

 

[moparguy]

Well, first thought is fuel filter. If you've just started using a bio blend in the last few thousand miles, the cleaning action of bio can restrict a good filter in no time.

Rig up a fuel pressure test rig and see what it tells you. Good tips here

 

[mwilson]

See if the fuel shutoff solenoid is opening all the way....

 

[fest3er]

Where does the AFC boost line come from? Maybe the AFC isn't seeing enough boost to allow full fueling....

 

[Missouri Mule]

Fuel pressure test! Lift pump especially if been working since 2000. Actually it's probably the original. NOTICE the truck was 97

 

[Joe Mc]

Not sure on a 97, but boost hose connections may be good "however" the metal tubes may have rotted and split in a difficult to see area? Check with mirror and flashlight for crusty areas/signs of a split. Another thought, possibly a bad horn to intake gasket? Oh, no mention of any gauges?

 

[surfbeetle]

My first thought was boost and also as was mentioned above, check the fuel cut off solenoid. The rubber boot can go bad and then get hung up with the solenoid and prevent it from pulling all of the way up in the housing.

 

[raxley]

I had a problem with low power, I was fine on the freeway (altho limited in top speed) but around town it was a real dog. It slowed over a long period (months or more) I replaced lift pump and hoses in the area and got rid of fuel preheater and that didn't do anything. I was ready to take out the tank and clean all that up too (diagnostics are NOT my 'strong' suit) Finally somebody asked if I replaced the 'return line spring' and I did so, power came right back, felt I was losing (or afterwards, gaining) 50 hp. Should have done it before the lift pump. They are only like $20-25. Fuel filters are cheap and easy too.

 

[ranger71]

Well, first thought is fuel filter. If you've just started using a bio blend in the last few thousand miles, the cleaning action of bio can restrict a good filter in no time.

Rig up a fuel pressure test rig and see what it tells you. Good tips here

See if the fuel shutoff solenoid is opening all the way....

Thanks, will do, appreciate the response!

I had a problem with low power, I was fine on the freeway (altho limited in top speed) but around town it was a real dog. It slowed over a long period (months or more) I replaced lift pump and hoses in the area and got rid of fuel preheater and that didn't do anything. I was ready to take out the tank and clean all that up too (diagnostics are NOT my 'strong' suit) Finally somebody asked if I replaced the 'return line spring' and I did so, power came right back, felt I was losing (or afterwards, gaining) 50 hp. Should have done it before the lift pump. They are only like $20-25. Fuel filters are cheap and easy too.

Sounds like my problem, power dropped over a period of time too. Cheap thing to try, gonna start there!

 

[DieselTick59]

Ranger, did you ever fix the problem? Interested in what you did to fix the problem.