hopin someone can help me on this..I have a 87 broncoII, 2.9 liter fuel injected. it's been runnin kinda ragged for a few days, like it wasn't gettin any fuel.so I changed both filters on it and it ran good for a few days. then a couple of days ago it started runnin really bad..like it wanted to die and would surge and falter a lot. then it died totally. then I was foolin around under the hood, lookin for the fuel pump relay cuz the guy at the parts house said to check to see if the fuel pump was workin. he said to take a voltage tester and check the pump wires. if there was voltage at the wires goin to the fuel pump, then the pump was bad. if there was no voltage to the pump then the relay was bad, which made sense. so I was lookin for the relay under the hood, and accidentally touched a wire goin to the battery..the relay clicked, the pump energized. so I fixed that problem and it ran good for awhile. now since it died totally, I figured it was the relay. so I bought a new one, put it on, and still nothin. I can crank on it for awhile and check for fuel at the fuel rail, pushin in on the schrader valve, and fuel will come out, but it still won't start. I tried jumpin the wires on the relay to make the fuel pump run, ya can hear it runnin, but it still won't start. ya can shoot some cleaner in the throttle body and it tries to start, so I know the ignition's ok. any kinda help anyone can give me would sure be appreciated..I'm startin to think the best thing to do is float test the truck..run it off in the river

 

Your truck has two pumps, one in the tank and one on the frame rail, are both running. When you pressed the valve did the fuel spray out or just run out? You should test the fuel pressure with a gauge.

 

I can get under the truck, and have someone turn on the ignition. I can hear the pump in the tank click, but not the one on the frame. but i know the frame mounted pump is good cuz I can jumper the connector for the relay and it'll run

 

forgot to answer your question..yeah..the fuel comes out the schrader valve, sometimes it sprays pretty high, other times it's like ya see a drinkin fountain..best way i know to describe it

 

Since you only get drinking fountain stream sometimes I would suspect a wiring/connector problem since the high pressure pump runs fine when jumpered and it seems that the LP pump is running all the time based on your description. The LP & HP pump run off the same circuit, the wiring just splits off for each pump.

 

Went through all this with my 88. all better after I changed the LP pump in the tank. Not too expensive either, so if you are unsure of the age of the pump, it might not be a bad idea.

 

2 things to check 1,Both the fuel filters .the one on the HP pump and the one on the the inside of the fram rail on the driverside.2.Check youe Inershia{spelling}switch for good conections and to make sure its good.JMO