| Airtex Fuel Pump Failure [message #340623] |
Sun, 03 February 2019 23:58  |
captjack
Messages: 271
Registered: February 2010
Location: Sebastopol, California
Karma: 1
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Because my coach is a vapor lock queen, after making all the modifications recommended by various experts which didn't solve the problem, I finally installed in-tank fuel pumps about 5 years ago. They did solve the problem.
On my way to the GMC 49er Rally in Colfax, I suddenly lost power on a narrow, highly traveled road and wasn't able to figure out the problem until I had the coach on the side of the road with trucks and other vehicles whizzing by. I soon figured out what was wrong before I got run over and switched to the spare tank pump and continued on my way. Normally I would have switched over while the coach was moving and solved the problem. I did that but no quick response. The problem is that I have now installed a Fitech Fuel Command center which was completely drained and takes some time to fill and get back into action.
Anyway, once back home, I pulled up the carpets and removed and replaced the pump and decided to cut it open to see what was wrong. The pump contains a small electric motor driving a turbine pump. What had happened is that one of the brushes got stuck in its passageway and lost contact with the armature. No evidence of any contamination and lots of brush left, so it's a mystery to me. The tank was almost full, so the pump had plenty of fuel to cool it.
I also discovered those pumps are power hungry! I measured 3.4 Amps when running and pumping. That's 40 watts!
Jack Christensen - K6ROW,
'76 Glenbrook/Clasco - "The Silver Bullet",
Sebastopol, CA
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| Re: Airtex Fuel Pump Failure [message #340625 is a reply to message #340623] |
Mon, 04 February 2019 06:49  |
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RF_Burns
Messages: 2277
Registered: June 2008
Location: S. Ontario, Canada
Karma: 3
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Senior Member |
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Jack,
What model of fuel pump are you running? The Fi-Tech FCC is a low pressure input with a float, so the pump is dead-heading when the FCC is full. Electric pumps seem to be high volume for the amount of fuel the engine actually needs (10mpg @ 60mph = 6 gallons/hr). I'm guessing at wide-open throttle the fuel consumption can get up there. The Airtex E8094 for GM TBI is rated at 45-50 gallons per hour at 12-17psi. That's alot of fuel to move, hence the high current.
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.
1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that
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