Low Fuel Pressure

[92351w]

I have a 1992 5.8 351 motor in my bronco. I was sitting for a few years and recently put it back on the road. It ran great for about a month or so and no it has started stumbling and stalling. I had put i don't know 30 gallons of fuel through it plenty of injector cleaner, marvel mystery oil, and dry gas through the system. I have also changed the fuel filter it got better for a few days/ hours and now back to the same crap. Today i decided to go and check fuel pressure and with the engine not running it primes to 45psi which is the proper number. Now when i start the engine at idle it pulls anywhere from 15-20psi and at about 2000rpm 10psi. I know that this is way low, I'm curious to know if anyone has had a similar issue and or what it could possibly be. If anyone could help me , because maybe im missing something.

 

[Rons beast]

If it sat for a while there is all kinds of junk in the tank, and it clogged the new filter. Drop the tank and get it clean. The fuel sock on the pump is probably pretty clogged too. Then change the filter again.

Good Luck

 

[Krafty]

normal operating fuel pressure should be around 30 psi. I agree with ron, cleanthe tank and the sock and put another new filter on then do a fuel pressure test.

 

[miesk5]

yo,

When you ran eng to test psi;

Testing; "...Arun the fuel pump for 10 seconds. Check that the pressure is within specs, and it doesn’t leakdown more than 5PSI within 60 seconds after pump shutdown.

..."

Source: by Ryan M (Fireguy50) at oldfuelinjection.com

Check vacuum hose at Fuel Pressure Regulator; any gas or gas aroma in vac line indicates FPR diaphram is bad; replace FPR