Lift pump-cause?

[Rockcrusher]

Was reading Steve St. laurent post @ installing pusher pump at tank and notice he mentioned power to lift pump at only 3 volts at low speed. This could be part of the problem concerning commutator failure. Lowering voltage may be increasing amperage and causing more "arcing" and burning comm.

Just a thought. Maybe there is an electrical/electronic type out there that may have some thoughts about this????

 

[Steve St.Laurent]

I don't think I've ever said that Rockcrusher but it's always possible. If I did I was incorrect. The information that I currently have is that the lift pump is cycled on and off (12 volt) at a 25% duty cycle while cranking to produce a minimum of 7 psi while the engine is cranking. Sorry if I cause any confusion with a post post. I searched through my posts and couldn't find where I said that, but I could have at some point I guess.

 

[Rockcrusher]

Originally posted by Steve St. Laurent

I don't think I've ever said that Rockcrusher but it's always possible. If I did I was incorrect. The information that I currently have is that the lift pump is cycled on and off (12 volt) at a 25% duty cycle while cranking to produce a minimum of 7 psi while the engine is cranking. Sorry if I cause any confusion with a post post. I searched through my posts and couldn't find where I said that, but I could have at some point I guess.

Steve, I checked back and found the 3 volt comment.

It was a reply to Toolman on 6/26/01. I had pulled up your post on installing Carter pump. It just caught my eye and started thinking about it. You know what happens when we start thinking. Anyway, you must be on line to respond so fast. Thanks. I havent had any trouble with my new rig (less than 6,000 miles) but I want to be prepared.

Richard

 

[Steve St.Laurent]

Just found the post in question, I was wrong. Instead of turning down the voltage they cycle the pump on and off which I now know to achieve that 25% duty cycle. Sorry for the misinformation.