Interesting fuel pump problem

[wedged]

One of my projects is a '94 Dodge Dakota with an NA 440 that has an XFI EFI system on it. It's been together and running for about 2.5 years. I really don't drive it much at all-maybe 500-800 miles total during that time. I was long term planning at the begining with hopes of adding turbos, so I went "overkill" and set up the fuel supply system to handle 700 hp.

I've had an intermitant fuel pump problem. The truck had been running fine (well-running "ok" as I am fooling around with tuning the XFI). When the gas prices skyrocketed last summer I drove it less and it sat longer between uses. The truck gets about 7 mpg in around town stop and go- lots of traffic lights and no OD yet. I am guessing it was sometime about a year ago that i tried to start it and it would not fire. After cranking for a short period I realized I did not hear the fuel pump prime when I turned the key to run. I checked the fuses, relay and had power & ground at the pump, but it would not run. This is a high end well known inline/submersible pump. Since I had the pump for over a year at this point, I figured the warantee was expired so I took the pump apart. I found absolutly nothing wrong. No debris, no visible damage. I did not disassemble the motor itself. Upon reassembly the pump felt a bit hard to turn and still would not run when bench tested. I sprayed some WD40 into the pump and into the motor and turned the pump by hand. This seemed to free things up a bit. I tested again, and the pump ran. Re-installed the pump and then the truck fired right up.

Since that time I think I probably drove less than 100 miles, and the truck has been sitting. A few days ago, I wanted to move the truck. No start-no prime. Power & ground OK, so I pull the pump again. This time I pull the motor apart too and find that one of the magnets has become unglued from the outter steel case of the motor. One of the brushes looks very short, but i discover a broken piece of brush laying inside the motor. I call the manufacturer and the tech line says they see this when fuel with alcohol in it is used or fuel is contaminated with alcohol. These days, almost all pump gas has some alcohol in it ?? They have a special fix that they perform on the pumps for use with mini sprints which use motorcycle engine that run on alcohol. It sounded like they mechanically fasten the magnets rather than gluing them.

At this point I am not sure what I want to do. Put in a stock type in the tank pump that will be "good enough" for the pitiful amount of power my low compression 440 makes, or send the pump in for an upgrade that would cost no more than $200 plus shipping.

[wedged]

hmmmm.... been poking around on the web and I've discovered that this is a very common problem.

http://www.offshoreonly.com/forums/g...estions-2.html
http://www.rx7club.com/showthread.php?t=644970
http://www.honda-tech.com/showthread.php?p=38899110
http://www.moddedmustangs.com/forums...p-trouble.html

[camcojb]

Originally Posted by wedged

hmmmm.... been poking around on the web and I've discovered that this is a very common problem.

I had the magnets come un-glued on an Aeromotive pump years ago. They blamed the California gas, no warranty. I had it repaired by them, they use a different glue now and never had a problem again.

If that manufacturer hasn't got todays gas figured out then I'd be running a different pump. Maybe something like a WalBro or similar 255L pump that can handle 600-700 hp and be fine with the pump gas we all have now.

Jody

[wedged]

I'm toying with the idea of a new different pump, rather than fixing this one. XS and Walbro both have alcohol compatable pumps. The XS pump I'm looking at has similar specs to the pump I had and a similar price.

[GregWeld]

Wedged -- No way would I pay to repair that pump... for another $200 or less you can get a much better pump and not have that problem again.

PS -- On fuels...

I've been telling all my buddies that if their garages smell like gas -- to change their fuel lines - and DO NOT use anything that is rubber! Including the stainless braided stuff... I've switched anything that is flex hose - to the TFE (Teflon) braided stainless... and no more stinky garages!

So one of my buddies didn't believe me -- but showed up with his fancy new black braided cloth hose - I whipped him up a couple of replacements with the TFE stuff... and he goes home and calls me -- says "damn, I hate to admit it... but you're absolutely right... no more gassy smell!"

You'd think this was 10 or 15 feet of hose - but we're talking about 2 foot lengths!

Seems the "new fuels" under EFI pressures -- just blow right through the rubber... you won't see anything wet -- but you'll smell it!

[wedged]

i'm thinking i'll either try to fix it myself or switch to something that will pump acid...er, I mean today's "gas". I'm looking at all posibilities, perhaps one of the non flow-through type pumps. Then I should only have to worry about a seal failure ?


I've got a few feet of SS braided hose that I know is only going to last a certain amount of time.

[wedged]

I've decided to attempt a repair myself. I've re-epoxied the magnet that came loose. Next I'll apply epoxy around the other magnet- the edges are beveled so there's an undercut area between the magnet and the steel case I can fill with epoxy. I found a souce that I can order new brushes from. I tried to cross reference them to a hand power tool so could try to buy themlocally, but I could not find any the right size.

[wedged]

brushes ordered today - two sets 'cause they are cheap and with my luck I'll mess one or two up some how. I also bedded epoxy around the magnet that was still attached.

[camcojb]

good luck!

[wedged]

I got the pump working again. I'll post more details when I can upload the pictures.