[driceaz]

I have a 97 4.3. I started off having a harder time starting it in the morning. At first it would take 2-3 cranks before it would fire. Lately I have had more trouble starting it. 15-20 cranks or more. If I put some gas / choke cleaner in the throttle body it starts right up. Once it is started, it runs fine. Once it has been running I can turn it off and restart it no problem. From reading posts on here I suspected either the injectors, the pressure regulator or the fuel pump. I will be changing the fuel filter first to see if that helps at all, but it isn't that old.

I checked the fuel pressure. With the key on / engine off the pressure is about 58-60 psi (pretty much where it should be) after I have had it running for a while and turn it back off. The pressure seems to hold okay. So far so good. However, if I let it sit overnight and come back and turn the key on, the pressure will only go to about 48-50 psi. I can prime it several times and it never seems to go higher. This is when I can't start it. I assume that the pressure isn't high enough for the fuel injector. Still holds pressure okay.

Based on these results I think I can rule out the fuel injector / poppets as the main problem. That leaves the regulator and pump. What could be causing the pressure to be different if it is hot or cold? Is there anything else I can do to narrow it down? Any other ideas. I was thinking about trying a new fuel pressure regulator to see if it helps because I hate the idea of dropping the gas tank. But if this is clearly a fuel pump problem I will just go ahead and do it.

Would it be worthwhile to do a volume test of the fuel pump? Does anyone know how to check the direct pressure from the pump? (Should be like 75 psi I think).

Sorry for all the questions,

Any help would be appreciated.