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93 c3500 pump questions

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plumbtuf

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Location
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Picked up a different truck a while ago. its a 1993 c3500 ext cab. i bought it with really band blowby. I rebuilt a 660 with promaxx heads and a wuhaun whistler , got it put in the truck and now i have the hot long crank to start. So I am looking for a new pump, I would like around 90cc of fueling. Who's using who ? Classic Diesel , Moose diesel ?
Thanks
Eric
 
plumbtuf said:
Picked up a different truck a while ago. its a 1993 c3500 ext cab. i bought it with really band blowby. I rebuilt a 660 with promaxx heads and a wuhaun whistler , got it put in the truck and now i have the hot long crank to start. So I am looking for a new pump, I would like around 90cc of fueling. Who's using who ? Classic Diesel , Moose diesel ?
Thanks
Eric
Click to expand...
There, I put in a call for You. 😹
 
If I was going to order a pump from any of the "bigger" IDI performance companies it would be from R&D. Justin doesn't advertise GM pumps on his website. But they are identical to 7.3 pumps so he can build them. I was going to have him build my pump on until I went overboard and decided to learn to to it my self.

I've spoken with Wes (CDD), Justin (R&D) and a few other pump builders over the past few years and they have all been super helpful. Unfortunately most of the good DB2 builders have retired. Moose (Conestoga) had a good builder that left a while back. Nate got lucky that he was still there to build his .330 pump. And I recently seen a few pictures of some of the internal parts that Wes was "modifying" to cut corners and save money on his 90cc pumps. So as much as I like the guy, after seeing that I cant support that kind of work.

I can build pumps but I'm at least a month out. I haven't fully set myself up for customer work so I have to order parts for each pump. Its expensive to sit on that kind of inventory when starting out. Plus I need the extra cash at the moment to get my truck done first.
 
So , time for an update. I wasnt able to to get R&D to build a pump as he is swamped with the ford IDI stuff. The pump on the truck was getting so bad , that i pulled the trigger on a budget pump. My thought was how bad could it be. Well its bad. First pump showed up looking like it had been air dropped on the porch. It was all bent up, so I sent it back . The new pump showed up about a week later , and looked better . At least it wasnt bent up. Today I was able to install the new pump, but it now runs worse than it did with the old pump. The pump was installed straight up, and once started idled rough (air) and lots of white smoke. Bled the air out and went for a drive , the egts seem higher than before and while the white smoke had cleared up , it begins to return when coasting to a stop. Fuel pressure is set at 7psi . The HPCA solenoid being jumped makes the truck at least idle, smoke clears up and idle rises to around 900 rpm, but as soon the jumper is removed the smoke and semi rough idle returns. Any advice or thoughts on this would be alot of help. It seems that it is full advanced all the time. Something stuck internally? Can the gear jump time when you change the pump? The truck runs the same full advance or retarded. (great movie) . Pushing the advance plunger does nothing. Rockabillyrat you doing pumps yet?
Thanks In Advance
 
The HPCA solenoid advances the timing by reducing housing pressure allowing the advance piston to move. The marks on the pump are set using a special tool. Its completely possible that the line is in the wrong spot if the rebuilder didn't reset it after the rebuild. OR some slop in the timing chain and gears is causing your timing to be slightly retarted. I would rotate the pump to advance the timing and see if that helps.
 
Well then you can eliminate a chain and gear issue then. The mark on a DB2 is set for 1.5* +/- .5* of base timing. Once its at idle speed the timing advance will be about 4-6* of additional timing with the HPCA solenoid off. So with a timing light I always aim for around 8-10* total timing at idle.
 
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