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turn up the fuel on the 89-93 6BT's

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(Copied From TDG.com)

For the 89-93's (Bosch rotary pump)there's a screw behind a tin access cover about the size of a nickel. It takes a 1/2"(13mm) to break the jamb nut loose, then take the screw out. It'll have a metal band welded on it that needs to come off. Once that's off you can run the jamb nut farther out(towards the outside of the pump, about 2 turns). Then put it back in and test, some smoke more than others(especially with Lucas POD injectors!). The pre boost power adjustment is under a cover that looks like a vacuum diaphragm, and it is one. It has a torx bit with a jamb nut. Loosen the torx for more low end & tighten for higher. The governor spring is different than in the later 12 valves, and is not adjustable.

The other adjustment is to rotate the diaphram, under the top cover with 4 screws. Use the picture at right as reference. Turn the diaphram clockwise 90-120 degrees, this is like sliding the fuel plate on a 94-98. Now put it back in & test.

The best bang for the buck, is to get a gov spring, most of the time they are under $20, and let it rev up to 3200 rpm. If you plan on a gov spring, hold off on doing the fuel screw shown above, it needs to be close to stock setting.

Might take a look over here for more information...

http://mopar.mopar1973man.com/cummins/1stgen/inc-pump/inc-pump.htm

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i noticed on that picture it has a "mechanical" fuel shut off, but according to the bosch VE pump manual that is a mechanical retarding device for the pump, i activated it on my truck by hand and it did not shut off barely changed idle noise. so if you guys are looking for the old pull style shut off don't wast your time running a linkage for nothing :smart:

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i noticed on that picture it has a "mechanical" fuel shut off, but according to the bosch VE pump manual that is a mechanical retarding device for the pump, i activated it on my truck by hand and it did not shut off barely changed idle noise. so if you guys are looking for the old pull style shut off don't wast your time running a linkage for nothing :smart:

That funny... Taz here has a 1992 Dodge and his fuel shut off solenoid burned up so we took the guts out of it and put the dead shell back on the pump. When we use his truck for firewood hauling we pop the hood and grab the lever and it kill it dead. :shrug:

that's weird if u look at the VE pump manual in the download section page #34 it calls it the "Cold-start accelerator" when i first saw it on my truck however i thought for sure it was a mechanical fuel shut off, but i can tell u it doesn't shut my truck down unless something is disengaged inside that connects to it (highly doubt it) maybe it's something to do with tazs' pump ?????:shrug:

  • 10 months later...

A 3200 rpm spring (Bosch Part # is 1-464-650-366), pump tuning and a fuel pin like a Denny T stage 1 or 2 will add a good bit of power.Remember the non intercooled injectors are 155* spray pattern and will flow a good bit more than the intercooled 145* spray for the 1991.5-1993The POD injectors are about 150* and are the wrong spray pattern for both years. They are only a slight improvement for the non IC trucksI have 40HP, 5x.012, 5x.014, 5x.016, 5x.018 in 145*I also have 7x .010, 7x .012, 7x .013, +.... to about 7x.017 in both 145* and 155*

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