No Fuel Pump - Runs OK

[Bill Weber]

Started a trip a few days ago. Foggy and was watching road and didn't pay attention to fuel press. Noticed 0 press. Went another 12 miles to a truck stop where there was a lot of light. Stopped motor. Checked wiring on press transmitter - OK. Started motor & realized the FASS pump was not running. Went back home (25 miles). Rail press = 13,000. Found a bad relay on the FASS system - OK now.

I didn't think the truck could be started, restarted and run fine without a pump. The CP3 was pulling through the FASS system and the stock fuel filter. Amazing!



Bill

 

[AH64ID]

The CP3 is designed to pull fuel, its quite amazing it pulled that much thru a big pump like the FASS!

I know when I go to an external pump I will carry a short piece of hose to bypass the pump in the event it fails.

 

[AWeiman]

Don't some variants of the Duramax use the same CP3 without a lift pump?

(recall hearing that from a GM friend/engineer who works in fuel systems)

i have an uncle with an 01 duramax, and a buddy with an 08 powerstroke neither of the two have a lift pump. i find it odd that our ctd's have a lift pump at all. i am under the impression all 3 are running a cp3.

 

[AH64ID]

Don't some variants of the Duramax use the same CP3 without a lift pump?
(recall hearing that from a GM friend/engineer who works in fuel systems)

AFIK there isn't an OE LP on any duramax.

i have an uncle with an 01 duramax, and a buddy with an 08 powerstroke neither of the two have a lift pump. i find it odd that our ctd's have a lift pump at all. i am under the impression all 3 are running a cp3.

All 3 are HPCR, but I don't think Ford uses the Bosch CP3. I am also fairly certain the 08 PS has a LP.

 

[cerberusiam]

Don't some variants of the Duramax use the same CP3 without a lift pump?

(recall hearing that from a GM friend/engineer who works in fuel systems)

The relationship of the CP-3 to the tank is different in a GM and the lines are quite a bit larger to support no LP. Still, its worth about 30 HP just adding a LP and absolutely needed when running a programmer.



The CP-3's in suction applications also suffer a lot more failures than in a force fed one. The cavitation of the gear rotor pump having to draw fuel and create high pressure hammers the gears and the wear plate out much faster. Wanna guess where all that metal goes?



The CP-3 will draw adequate fuel thru a FASS or other vane pump if the lines have been changed as usually happens on install. Its just not a good idea to run it very long like that.

 

[AWeiman]

i have an uncle with an 01 duramax, and a buddy with an 08 powerstroke neither of the two have a lift pump. i find it odd that our ctd's have a lift pump at all. i am under the impression all 3 are running a cp3.

ya i went back and did a little research and the powerstrokes do have a lift pump, i guess my buddy doesn't know his truck that well. was just going with what he told me, we had a conversation about it when his injection pump shot craps at about 50,000 miles. dang junkers:-laf

sorry for the misinformation.