Engine/Transmission (1994 - 1998) 1100 rpm miss

[riles]

Is anybody aware of a cure for 94-95 Cummins with an 1100 rpm miss that is enhanced by fueling mods. It seems to get worse in hotter weather and happens at light throttle and is worse the more fuel you have available

 

[Signal73]

step on the pedal some more.

 

[PRattenbury]

Set the governor springs so it idles at 1200? We've done that before, haven't we, Jim?

 

[Jim Fulmer]

If you are familiar with exactly how to set the AFC up then you may try sliding it back some, obviously don't just do this using the force. Setting it up for say 35-40 psi, meaning it takes that much to get the arm to fully travel. Seeing you have Twins you should have a tight spring in there (215 pump type) and of course all of the internal tricks done.



Sometimes this helps as it gives the Gov arm something to rest against if you will, there have been times when the arm just hunts back and forth a little causing this issue.



Mine does it at an idle, especially in gear, but it's from a sloppy Governer that needs to be rebuilt.



Jim

 

[Extreme1]

It's the 130 delivery valves. Some 180's can be had cheap and will help, the 190's were innitially utilized to cover up this miss in the 140 and 150 HP pumps.

 

[JacobsD]

Can timing effect that? I thought it was because my timing was off that it was doing that after I put the injectors in.

 

[riles]

We tried 191 dvs in my nephews 94 and lazer cuts in his buddy's 95, 022s in a friends 94, a cam plate in my best friends dads 95 and in all cases it magnified the problem, I know of two bone stock trucks in this area with the same problem, I think we'll try rebuilding the governer in my nephews truck. We had considered putting my Fluidamper on my nephews truck befor We put it on mine, but I think we'll try the gov. first.

 

[Signal73]

The 160 pump likes to stumble in that range with fueling mods, it mostly has to do with the cam profile, and fill time in the plunger/barrell assembly. Bigger d/v's almost never seem to help just move it up in the RPM range or make it worse alltogether.

 

[K5IP]

My 95 had a stumble (lightly loaded), between 1000 and 1400 RPM. Mine is a 5spd, i. e. 175hp.

Most of the uneveness, not missing really, went away after I installed some 215 injectors. I always thought perhaps there was always an injector problem from the day it was new.

Rog

 

[Desperado]

My 95 had the same problem at 1100 rpm's and again at 1800rpm's, what I found was the gov. springs were one click off from one side to the other, set them the same and all is well.

 

[Howard Durand]

After warm up, My 94 has always had a little jiggle at idle but smooths out nicely at about 1300 rpm. Idles better when cold.

Since this appears to be common with this pump, I am going to live with it.

It hauls my trailer up and down hills with ease so I am inclined to quit messing with it.