nickg

Eric
If you already have a drawstraw, you dont need to update it, if you DONT have a drawstraw, then there are all kinds of potential problems if you dont instal it properly, do a search for "1/4 tank issues" or something to that effect, if the straw in installed wrong you will loose fuel pressure or run out of fuel at 1/4 tank.

The 100 hooks into the existing fuel module, so your fuel gauge/level will not act any different than it does now. You would have to look it up but I seem to remember the 100 is good to 500hp and some have run above that. I bought the 150 at the time cause it was the same price as the 100

The 150 requires a draw straw instal, many drill their tank to install it, I drilled my fuel module and installed two drawstraws, I fiqured if I drilled the Module it would be cheaper to replace if I screwed it up vice replacing a fuel tank.

My problem was I never ran out at 1/4 fuel, but had pressure drops to 2-3psi when stopping or turning quickly when I was at 3/8-1/4 of a tank. so I routed the Airdog return that normally goes into the filler neck into the fuel module, The AD moves so much fuel that it was sucking the module empty when at 1/4 tank or less, with the AD return dumping fuel back into the module, the AD was not running out of fuel.
Here is a thread I posted on the other forum, there are is some good info and a couple other links to help you out

http://www.cumminsforum.com/forum/98...vs-carter.html

Here is a link to AD, explains the technology, and it shows all the stuff that comes with each pump kit (drawstraw/hose etc)
http://www.pureflowtechnologies.com/AirDog.htm

badme

Thanks for the help. I ordered the 150 on Thursday for the same reason you did, they were the same price as a 100. I figured I only wanted to do this once and this will allow future upgrades. I have my return currently going to the fuel filler and my pick-up is at the module. My module is just a blank module with a sending unit and a draw straw. Do you think it will be ok?
Thanks
Eric

redpoint5

Out of masochistic curiosity, are campaign pumps still offered through Cummins? My campaign just failed after only 10k miles of easy use, warm temps, and clean fuel.

Also, does anyone know what usually fails on these motors? Bearing, windings, commutator, brushes...?

Edit: I notice a lot of air rushes in when the fuel cap is removed. Is this normal and could that vacuum be causing the pumps to fail prematurely?

nickg

I think the failure rate is a combination of everything you mentioned not to mention the plastic drive ring(see moparmans pics)
Heavy vacuum will work against the pump, and if you have ANY leaks in the return side it will cause hard starting as the fuel is sucked back to the tank after sitting for a while, usual culprit is a faulty fuel cap or a plugged fuel tank vent. try removing your fuel cap and look at the bottom you will see a black button on the center try depressing it with a pencil(eraser end) or something silimar. it should push easily, it actually may be stuck and require a fair bit of effort to get it to move. once unstuck it should be OK, just monitor if the tank shows high vacuum/pressure.

nickg

It may be ok, but if you have 1/4 tank issues (low pressure drops during braking/turning) you can always add another drawstraw to return the fuel back into the module.

so do you have fuel pressure issues now? as I stated in my post (see other link) the stock pump only used the fuel the Engine needed so it NEVER had a pressure issue, the 150 moves a lot of fuel, circulates it back to the tank, so once the tank fuel level gets low it starts sucking air as the fuel rushes back and forth past the draw straw. if the return is back in the module the returning fuel replaces the fuel that the drawstraw removes less the amount needed by the engine.

again worse case is you have to add another DS, good thing is your AD150 comes with a drawstraw.
Carry a couple of wrenches(bleeding VP & injectors) and a spare can of fuel, run the tank low on purpose to see what happens. keeping a close eye on the fuel pressure gauge while doing a couple of hard stops

good luck

kind of boring now to watch the fuel psi gauge, 16 at wot with edge set on lvl 6.