Trouble with Sierra 18-7331 Elecric Fuel Pumps

[tank1949]

I posted this elsewhere. I hope someone who has experienced my concerns can relate to me. I connected digital thermometer under band that fastens or holds Sierra 18-7331 pump to stringer. Band wraps around pump and looks something like a band or connector to attach coil to the block. The thermometer had good surface contact and never got greater that 117 degrees F at first and cooled down to 107-110 as we raised the V8's RPMs to around 1500. I suspect gas flow cooled it. But, I am concerned if this is too hot? We are working in shade and air temp was 91 today. Wires going to and from were not hot, so I suspect good contact as far as wiring. If this is too hot or operating range, please advise. It just feels too hot to me but thermometer provided exact data.

 

[Another retired guy]

Re: Trouble with Sierra 18-7331 Elecric Fuel Pumps

I can't comment from personal experience, but 107 to 117 doesn't seem too hot considering you're in ambient shade temperature of 91.
The 7331 is a replacement for specific year 454's and 502's. is it correct for your engine?
Have you checked for partial blockage in fuel lines / filters / pick-up ? Restricted flow will cause pump to work harder.

 

[tank1949]

Re: Trouble with Sierra 18-7331 Elecric Fuel Pumps

Another Retired Guy, Thanks for replying

I have never used electric fuel pumps until this I bought this barge. I contacted Sierra teck who recommended this specific pump for 350 chevy carburated blocks. It is low pressure for carburated motors. He stated, also , it would work on big block and v6s. I had an issue with E87 crap gas, as everyone else has, but the fuel in my tank has been treated and replaced. Years ago, before alcohol was added, any water collected by water/filter separators could been easily seen if you poured filter contents into a 5 gal bucket. Now, I don't know if that is the case with gasohol???? Refiners may add something to fuel to increase the absorbtion rate, and it is my understanding that alcohol by its nature will absorbe water. I use Sierra 10 micron spin on fuel/water canisters. I assume these are filters too?????? I dumped filter contents and there WAS crap, but I could not SEE any water. My neighbor and I have spent a fortune (me) and a lot of time getting this barge ship-shape. Hence, I may be overly cautious! Any suggestions are welcomed.

 

[Another retired guy]

Re: Trouble with Sierra 18-7331 Elecric Fuel Pumps

The ethanol gas and water issue has been discussed many times here but it's got nothing to do with the operating temp of the fuel pump! The crud in the fuel filters is of more concern.
Electric pumps are cooled by the fuel as it passes through. If the fuel temp is also 91 or maybe higher, it doesn't have much cooling capability. If that pump was on my boat, with overnight temps now getting down to the low 50's, I bet the pump would run much cooler!

 

[tank1949]

Re: Trouble with Sierra 18-7331 Elecric Fuel Pumps

Another Retired Guy,

Here in Pensacola it is HOT. I may have been too cautious, but I have experience nothing but problems wit this barge and don't want any more than I can fix now and not have to later on fifty miles offshore. I'll replace filters again and go for a spin. Thx for contributing.