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Tech Talk => Engine Mechanical / Electrical => Topic started by: hondo76 on July 16, 2016, 09:19:07 PM

Title: Losing fuel pressure
Post by: hondo76 on July 16, 2016, 09:19:07 PM

I have a 1974 455 olds with red inline Holley fuel pump (new) . Holley 850 double pumper. Runs for a couple min and loses fuel pressure and runs out of gas when gas tanks  are clean and full. New lines all the way through. new fuel filter? Any ideas what the issue could be?

Title: Re: Losing fuel pressure
Post by: Your Mom on July 17, 2016, 06:46:00 AM

Is it mounted below the fuel tanks? Electric pumps push fuel. Have had a few friends run both styles inline together mech/electric. Best most simple way to chase a fuel issue is to get a small fuel container an put your line in it from pump. That will set you in the right direction once you see results.

Title: Re: Losing fuel pressure
Post by: vwagon13 on July 17, 2016, 08:32:32 AM

If you can't find anything wrong with what your Mom States:

 Disconnect the electric pump all together. Then see how it runs with just a good mechanical pump.
 So many good high quality, high gpm mechanical pumps available from both Mondello sites now , I question the need for electric.
Just my 2 cents however. Nice-looking float. And welcome to the site.

Title: Re: Losing fuel pressure
Post by: B.CR33CH on July 17, 2016, 08:48:42 AM

Fuel tank pickup, Everything is Nice and tight. How far is the pump away from the tanks what size lines are you running are you getting a full 12v to your fuel pump? All things I would check 


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Title: Re: Losing fuel pressure
Post by: Ralph Brunt on July 17, 2016, 10:11:33 AM

are your vents clogged? remove fuel cap to test.. cheapest and easiest checks first