Just returned from the SouthEast Nats and unfortunately, about 30 miles south of Atlanta on I-75 the fuel pump died. To make a long story sort, I replaced the pump in early September making this the 3rd one in less than two months. I've been using 5-7 pound pump from a '92 Marquis. It's mounted on the crossmember over the rear and has a new canister type filter ahead of it as well as the filter that comes with the pump. Any ideas as to what could be killing these pumps?
I've got a '69 Firebird subframe and the motor is set too low into the frame to allow clearence between the block and frame for a mechanical pump.
Any input will be appreciated.
mike


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chopper
Never argue with an idiot. They drag you down to their level then beat you with experience.

I may be way off base, but if your pump is mounted above the fuel tank, this could possibly contribute to the short life of the pump.

Everything I have read, has suggested mounting an external pump as low as possible, such as on the frame, at or below tank level.

These types of pumps work best when they have a "flooded" suction. ....They are designed to "push" the fuel forward, and have limited suction (lift) to "pull" the fuel from the tank.

Something else to consider: ...Most gas tanks using an in-tank pump, have a reservoir around the pump pick-up, to keep the pump from sucking air while accelerating, cornering, or braking. ..... If your fuel pick-up in the tank does not have something around it, your pump may be momentarily running dry, which will DEFINITELY shorten pump life.

Keep it low, put a filter between the tank and pump, make sure you have it away from heat and you get plenty of ventalation around it. Also use rubber to insulate it between the mounting bracket and frame.
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Emil
GCi
http://groups.msn.com/randomrodders
Drive it!
46 Ford Sedan
37 Packard Super 8

You didnt say whether it was the electic side of the pump or the pumping portion thats going away. I would bet that its the electrical side. A common cause on high output drag style pumps is a voltage drop because of too small of wire size . This supposedly causes a higher amperage draw and this causes the motor to burn up. The fix is to use your present wire to the pump to trigger a relay which has a heavier wire say 10 or12 guage feeding the pump.

This has me stumped. Everything you fella's covered has been done. The pump is mounted in line with the bottom of the tank, the bracket is insulated, the pump wiring is 16 ga and there are two filters between the tank and the pump. The first pump [same one]lasted five years mounted exactly the same way. I am sure that it is the electrical side of the pump that is dieing because there is gas all the way up to the carb (clear filter) and no humming coming from the pump.
mike
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chopper
Never argue with an idiot. They drag you down to their level then beat you with experience.

16 ga wire sounds awfully small compared to 10 or 12 ga.
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phil


It's not a NOMAD, it's a Yeoman!
Not an engineer, but I DO drive a train.

IMHO that pump designed to run in the tank probably won't last long on the frame rail because of the heat it generates. If it were in the tank the fuel would keep it cool and probably make it last longer.

My suggestion would be go buy a Carter electric fuel pump (I think the part # is P4007 or P74007 or something like that).I think Airtex has that pump also. It can be purchased at Carquest (for sure) and NAPA too I think. I ran one on the '32 I built for over 10,000 miles and sold the car about a year and a half ago and the new owner is still running it. It's designed to run external.

Just my .02.

Lynn
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'32 Ford Tudor

The Mallory 140 pump seems to be the electric pump of choice on the Performance forum of the www.chevy.org website. They are quieter than a Holley and more dependable. I have also heard good things about Carter units.
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Lynn
'32 3W

I have abs of steel. For the protection of others, they are covered with padding.

You got it rumrumm ,i have been running the mallory 140 with the included external regulator for a couple years now. A totally dependable fairly quiet pump,once it pressures up and it has replaceable brushes also. This pump is a gerotor gear design (similar to some engine oil pump gears)this is why they are so quiet. Be sure to insulate the regulator from direct engine heat transfer to the mounting bracket it is fairly sensitive to temp changes causing pressure to vary slightly during warmup to operating temperature The holley pumps are vane pumps which is why they sound like a full porters trunk is dragging on the highway at the back of your ride. Also on a holley pump if any one of those vane cracks the pump jams and she stops right then. If your running a holley tee in a backup to get you out of a jam if needed.

I Don't have an electric pump but I here some many failures of aftermarket so called [performance] fuel pumps. what gives, factory OEM pumps don't have this failure rate.
Dave
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dave

Howdy Red 32 i would believe the failures of some of the aftermarket pumps ive seen comes down to some of these possibilities 1)Undersized wiring causing a voltage drop and higher amp draw causing the motor to burn up sooner over time. 2)dirty fuel or poor maintainance 3) No free flowing filter installed before the pump 4) Letting your preset fuel pressure drop over time and not monitering it and over time the pressure drops down low enough to where the pump surges and runs hot from this, the surging is caused by the regulator springs hunting because they weren,t designed to operate at that level. 5) mounting the pump in an area next excessive heat or vibration probably lots more reasons out there . About failures of stock pumps , please go to the fridge and pop the top on a can of suds for anyone who now shows up that changed a stock small block chevy mechanical pump because the pivot portion was broken in side the housing and the pump arm was jammed.

Thanks for all the input, guys.
I'll be looking into either the Carter or Mallory pump as a replacement. Weather here is starting to turn sour which means time for upgrading and tweeking.
Thanks again.
mike
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chopper
Never argue with an idiot. They drag you down to their level then beat you with experience.

Lynn hit this one on the head, If that pump was designed for internal tank use, Then that is the problem. They need to be submerged to keep them cool or they overheat and burn out.
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WPoC