Fuel pump question

[Ragged out exploder31]

it will change AFR depending on the temp it reads. forget which does which. one goes to the cluster, one goes to the truck. if you have a scan tool you can see what the ECT is reading

It’ll start up and idle but will flat out die when you put it in gear but sometimes a little gas and it’ll go for a second but absolutely hates any kind of uphill grade will fall flat on it’s face

 

[rprice51]

2001 Ford Explorer sport 4.0 auto . When I go to start I turn the key on and let the pump prime and when it quits I can try to start it but it won’t hit, but if I cycle the key on/off 3 or 4 times it will fire up , I’m thinking it’s could be either a bad/weak fuel pump or a bad check valve . I gonna check fuel pressure at the rail tomorrow but what’s everybody’s suggestion? It also stumbles real bad if you try to rev it up and it’ll die if you put it in gear and try to give it gas to take off

My guess is the fuel pump. I had intermittent crank but no start issues with my 2001 Explorer w/ 244,000 miles. I finally connected it to the fuel pump not coming on for the 1 - 2 seconds when the key was turned on. New fuel pump fixed the problem.