Engine/Transmission (1994 - 1998) When To Check Pump Timing? Help?

[CEdwards]

I have been searching old threads trying to learn enough so that I can check my timing and adjust my valves. While researching that I have seen several discussions on pump timing, but I'm not sure why you would need to do that. Is it because of other modifications or is it something that changes or needs to be checked? I'm confused about it and nobody has said why or when to do it. any help would be appreciated.

 

[csevers]

If you have not timed a Cummins before I would suggest having some one help you through it the first time. You need some special tools depending on witch way you do it.

There is no set schedule for checking timing, guys check/change the pump timing for several reasons it can help mpg, power,how it starts. Some are set 1/2 or more degree off from the factory. The factory sets the timing at a different level for different pump models ie auto vs manual and to meet epa B. S. If your truck was white smoking or "snaping/crackling" and running very poor that can be a sign of the timing being off.

Simply changing the timing can make a very nice improvement in the way it runs.



Good Luck

Craig

 

[JGK]

Unless it's been changed and not done properly, the timing on a P-pump doesn't typically change. It's very rare to have them slip. However, they are not always set at the factory quite where they should be. So most owners check it just to see where it actually is.



For the most part, it is set at the factory for longevity, emissions, and all-around reliable performance (i. e. conservative, or on the retarded side - yeah it really is retarded!). So advancing it a bit ups the mileage and performance a little depending on your other mods, but emissions of certain byproducts in the exhaust goes up.



Craig is right. Unless you are pretty confident in your mechanical abilities and have spent a lot of time researching this issue, its best left to someone who knows what he's doing. I'm not a mechanic, but I'm reasonably mechanically inclined and a friend (helicopter mechanic) and I were able to time mine and his by just following the how-to write-ups. We've done several more since then. And it does take some pricey tools that are impractical to buy just to check it or change it once.



-Jay

 

[Vaughn MacKenzie]

I've timed two trucks now, did it using instructions I found on TDR and using the Snap-On timing tool kit.



For trucks with stock injectors I wouldn't bother with it, as soon as you put bigger injectors in it helps to advance it more because the larger nozzles take longer to ignite.



Vaughn

 

[ABorchard]

After timing several dozen trucks my feeling is every truck should be checked at least once. I would say the number of trucks whose timing was off either from slipping or set wrong at the factory exceed the number that are set to specs. Some have been off by as much as 6°.

If you're going to check it might as well change it, 15. 5 - 16. 5 seems to work best for most folks.