Archived Occaional turbo lag on aceleration

[mpcab]

I was having this problem when pulling loads. I took it to a Cummins shop and they said my lift pump was bad. We replaced it but the problem didn't go away.



Anyone have an idea?

 

[cumminspwr01]

You should fill your sig in so we know what kind of truck we are talking about. If its a newer truck are you getting a check engine light or any codes?

 

[bmoeller]

Need more info. How is it acting? Depending on what is going on, it could be as simple as a dirty fuel or air filter.

 

[RankRam]

Did they change the fuel filter?



Have you checked the intercooler clamps?



Does sound like a fueling problem though.

 

[mpcab]

Sorry, it's a 2002 HO. 6 spd. with about 140,000 on it. The fuel filter and air filter have about 3000 miles on it. I know this doesn't necessarily rule it out with today's crappy fuel, but I was wondering if there was anything else.

 

[RankRam]

I would change the fuel filter just to be sure. Also you can get an idea how the lift pump is working when you do the filter change.



I don't know if you know this, but it is critical to have a fuel pressure guage on the 24 valve trucks. The VP44 needs fuel at all times and the guage on my 99 was very instrumental in the replacement of three lift pumps within the 55k miles of ownership.

 

[cumminspwr01]

Do you have the three must have gauges in your truck (fuel psi, egt, boost) or are you just going by the old seat of the pants gauge? Also has the truck put out any codes?

 

[mpcab]

Thanks for the input, everyone... . I've been on the road..... we've about decided it's the crappy fuel we've been getting at some of the truck stops... . mainly Schell... we've had to replace fuel filters twice in the last 5,000 miles... this fixes the problem for a while, then it's back to the same old thing.

I don't have gauges to tell me specific fuel pressures, but I plan to have soon. If anyone has any other ideas that might help, I'd sure appreciate hearing from you.

We pull a 3-car hauler and it's really a bummer if you get into some mountains and "she" quits pullin'...

 

[bpenrod]

Twice in 5000 miles sounds like something is up in the tank! Can you tell what clogging the filter like dirt or algae or ?????

 

[nmurray]

I think that I had the same problem. I have a boost, pyro, and fuel pressure gages. I would be all of the way in the throttle and the boost and exhaust temp would stay the same and the truck would not accelerate. Then all of the sudden it would take off. I can not remember the code number but it had something to do with fuel pressure or fuel pump timing. I watched my fuel pressure when it happened and it would not dip until the truck would start to take off. I took it to the dealer several times and they cleared codes but could not duplicate. Eventually they got the OK from DC to change the VP44. I have not had a problem since.

 

[nmurray]

I forgot to say the code was in the memory but the check engine light never came on, which according to what I have read, should have happened. Cycle your key three times and leave it in the on position the third time and the codes should come up where the odometer is.

 

[Makensmoke]

My truck has had a horrible lag off the line for the last 80k. I've learned to deal with it and have blamed it on my turbo. It'll spin the tires once it gets spooled up, but off the line it sounds like i'm holding my foot on the brake. Could also be my torque converter failing i'm thinking, but both parts are big dollars so i'm going to stick it out till something fails. I've just got to time the lights a little better than the fords and chevys next to me on the way home from work.