Big Cam 400 III Sluggish Throttle
 

I've just replaced the injector pump in my truck w/ a genuine Cummins rebuilt pump. I gave them the engine nos. etc. so they had the info. Truck starts fine and idles fine but is very sluggish on throttle response/acceleration. I haven't taken it on the road yet. Anybody know what's wrong?

Not sure on the sluggish responce, but try gettin in touch with these guys. I read through the horsepower articles months ago and they really seem to know a BC Cummins better then it knows itself.
http://www.dieselinjection.net/frames.html

fuel delivery issues.......hows the filter look??

Timining maybe? Might have it retarded to much, or advanced to much?

I was thinking timing may be a bit advanced. Hows it idle, nice and smooth? any smoke?

If that was a Cummins Recon pump I will bet that the aneroid is adjusted a little wimpy.
The adjustment is behind the tin plate where your throttle lever clamps to the pumps throttle shaft. Behind the plate you'll see a set screw. Loosen the lock nut and turn the set screw counter clockwise about a turn and a half. That will put the pep in your step again.

Thanks for all the replies, guys. As it turns out, I need a pressure signal for the AFC.The old pump didn't have AFC. Anybody know where in the engine I can get the signal. I understand it is from the intake manifold but I need to use turbo boost pressure. I checked the 1/8" pipe fitting plug on the lower side of the aftercooler but I'm not getting any positive pressure so I guess it's the wrong place.

You wont get any pressure unless you put a load on the engine. Any plug in the charge air system will work. You may still need to adjust it a bit like Snedge suggested.

If I don't get any pressure w/o load, I'm in trouble. The rpm rises so slowly when I advance the throttle that I don't think I can go anywhere. I hooked up a small air pump to the afc by rubber hose and pressurized it w/ 25 - 30 psi. Wow! What a difference. Very snappy response. So, can I expect that only if I drive under load? Doesn't seem right. Thanks again guys.

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Well guys, I gave up and took pump back to the Cummins dealer. Guess what. After some research they discovered that they ordered and sold me the wrong pump! Needless to say I was a little upset and let them know it. At the same time I was relieved that a problem had been found. They are having it recalibrated and I'll let you guys know how it runs.

I guess Snedge was closest. It is a pump adjustment.

More after I reinstall.

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Installed the pump today. Works great. Let this be a lesson to everybody. Just becuase the recon part came from the dealer, it may not be right. Thanks again to everyone who helped.

Cody, Glad you got it figured out. I agree you can't always assume you will get the right part just because the guy who sold it to you had the right shirt on. I'll have to admit though, it's tough to screw up now a-days with the automation of parts ordering. If you gave them your engine serial number to start they should have all the tools to get you the right part the fist time.
Good luck.