[mpieper]

I need help w/ my 95 12V, it start and runs fune for about 5-20 miles then idles rough and seems to not have as much power. What might I look for?

Thanks for any advice!

 

[clc]

A few things to check (in this order) are: strainer in the fuel preheater (gets clogged), the fuel filter could be dirty or contain water, the fuel tank vent could be clogged (a fuel pressure gauge would give you some insight into any of the the preceding occurring), the valves clearances could be too tight.

Any white smoke when it starts to run poorly (can be caused by fuel starvation).

 

[mpieper]

Poor idle

I have replaced the fuel filter with no change. If I drain the water seperator, it runs good again for about 5-10 miles then runs rough again.
Appreciate any further advise on making this thing run good again!

 

[Joe G.]

Try removing the fuel tank filler cap to see if that affects the problem.

 

[mpieper]

I did remove the filler cap, no change. I thought maybe I ahd bad fuel but took a sample and let it sit for 2 days, no water found. Fuel filter was changed also.

I think next I will look at the fuel pump strainer filter and see if it's clogged.
How do I check to see if the fuel tank vent is clogged?

 

[Joe G.]

If it runs ok with the filler cap off longer without a problem than it does with it on, then the vent is suspect, otherwise it is working.

 

[mpieper]

Cleaned pre-heater screen (very dirty) now truck runs worse and blows blue smoke. Please help!

 

[Joe G.]

It appears that it is something that depends on the truck being warmed up. Look here for possibilities: http://www.cumminsforum.com/forum/94-98-tech-articles/58777-joe-g-s-fuel-system-writeup.html

 

[mpieper]

Thanks, Joe G for the excellent info, I will further investigate tomorrow.