I have seen a few posting regarding the S-10 fuel system and am showing signs of trouble with my 2000 4.3L V6. After sitting for 1-hour or so it takes quite a few turns to get the engine started. I have checked fuel pressure on the system just after shutting off the engine and have pressure. I have not checked PSI on the system (don't have a guage). I thought I heard hissing or an air leak near the fuel tank after checking fuel pressure. What could be causing the loss of pressure? I can hear the fuel pump running. Had my electronic ignition replaced 2 years ago. Any ideas?

 

since u haven't mentioned finding any visable leaks, it sure sounds like the pressure is bleeding off the pump. u really should do pressure check on the system when it's off, and check it periodically 2 see if, when, and by how much the pressure drops. just how long do u crank it 4? 1 second? 2...3.....5!?

 

It is a 2 - 3 count before it finally turns over after sitting over night (which is much longer than normal, usually a quick hit of the key fires it up). I agree with you I need to get that pressure tested to see how quickly it goes down after the engine is off. Doesn't the fuel pump initiate when the ignition is switched on? You would think that would sufficiently pressurize the system.

 

if the pump is not keeping the pressure up while the truck is parked, the quick pressurization u hear @ start-up is not enough to pressurize the system-remember, the pump could b bleeding off all the pressure in the system. kinda like changing the fuel filter and not getting the new one on & done up right away, so the 1/2 to 1 second prime doesn't fill up the 12 feet (or so) of fuel lines 2 the injectors.

 

If I'm not too late with this, you should also check your gas cap as well. A bad seal on the gas cap could alow the pressure to escape!

Good luck,
Larry