Engine/Transmission (1994 - 1998) Engine shudder @ low RPM

[okayred]

I just installed a #6 plate and Bosch 300's from Industrial Injection. I noticed a substantial increase in power! I also noticed that when I'm in the 1000 RPM range with slight throttle in third, fourth and fifth, the engine shudders until I either let off all the way or give half throttle.



I have heard that this is caused by (1) injection pump timing not set for performance or (2) incorrect governor spring tension causing "hunting".



Has anyone experienced this before and if so, what should I do?



The turbo, intake and clutch are all stock.

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1995 Black 4x4 Dually, NV4500, 4. 10 gears, KDPinned. #6 plate, Industrial Injection Bosch 300s, EGT, straight pipe...

 

[Troutman]

I have heard that if you run bigger injectors with the stock delivery valves it will cause that shudder. Im not sure if that is what is causing it in your case. Just putting a thought out there.

 

[JacobsD]

I've heard its the way injection pump cam is set upand you cant do anything about it on the 160 and 175 pumps

 

[WBerry]

If Your Timing Is Set At Stock Settings Try Setting It To Around 16. 0 Degrees

 

[RyanStewart]

Mine does that too at just over 1000 rpm in 2nd or 3rd gear. Started after I put the #10 in. I've just been down shifting, but I'd be interested to know if theres some way to stop it.

 

[okayred]

Thanks for the help.



I will have the pump off this week and when I re-install it I will adjust timing to 16*. I'll also one-up the delivery valves.



Does anyone know at what point I will need to upgrade my low pressure fuel lift pump?

 

[BHuebner]

upgrade the delivery valves to 181's or 191's before you mess with pump timing.

 

[okayred]

any thoughts on a good place to buy the 181's? Are they expensive?

 

[BHuebner]

Check PDR Diesel Inc thats where i purchased mine. give them a call and tell them what you're running.



Brian