Engine/Transmission (1994 - 1998) Low RPM Stutter

[Jfam]

I am in the midst of a huge frustrating problem. My truck has been in the shop for 6 weeks now and the problem has not been solved, though I am convinced Olee is working his best on it.



The problem is after the 500 hp build (see signature) of the '94 Cummins Dodge, there is a stutter only in the 700-900 rpm range. It became magnified when Olee did the trans build as everything is now tighter. We reduced the timing to 16. 5, but that did nothing. Olee sent the new injectors (Industrial Injection) back to the manufacture for inspection/replacement. That was not the problem When I saw him today he is going to replace the 7mm valves that was part of the build with the original ones, after consulting Harry (Peal Diesel Performance and former partner with Piers) and others



I am really very disappointed at this turn of events and am reaching out to all those who have vast experience with the 12 valves. Is there anything else you can think of that might be causing this? Olee Poole, (Power by Poole) who has the truck and did the transmission build, said he would appreciate communicating with anyone who can help: www.powerbypoole.com



Thanks so much,

Joe Fam

 

[SReeves]

My 94 did it at about 1000 rpm. Lawrence at Diesel Dynamics in las Vegas was able to tune out the shudder with out a detune. My current pump does not fuel as much so I rarely notice any stumble/shudder now. It was very bad at light go pedal input,the only way I could make it stop was to change the throttle position to rev above or below that rpm

 

[Jfam]

Problem fixed! Though maybe not solved in terms of physics. Anyway, the 500 hp build included 4K governor springs. There is some question about the installation, but in any event, when the “center springs” were removed it supposedly put the governors in a 3K mode. It worked!

Thanks to all the TDR members and others that contributed to the fix. In particular:
Casey from hhtrucks.com, Harry from Peak Diesel Performance, Olee from Power by Poole, and all the others. TDR is GREAT!