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Helping a family member with a 2.9 L 87 Bronco II. There's a fuel problem as I'm getting no pressure with a gauge (0 psig) on the Schraeder valve on the rail. I jumpered around the relay and intertia switch in the cab to be sure. I still don't hear a fuel pump kick on in the rear. but I'm not sure how audible that one is supposed to be. I'm not familiar with two pumps in series. If at least one was functional I imagine I'd see some pressure on the gauge, maybe not to spec though?
Update here, a couple of problems so far. The fuel pump relay or its connector has a problem. There is also a disconnected ground wire on the high pressure pump. Getting that back on is kind of challenging with the pump in place. Jumpered both of those and got 40 psig on the gauge. Things are looking up,
If you don't already know, and if you need to, you can ground out pin#6 on the ODB1 connector and both pumps will run at KOEOff. I had to do that to hear my Lpump run in the tank and i could jump 1 at a time because there is a splitter plug under the shield that's under the master cyclinder. I was able to use a 4 ft wooden dowel to unhook the pigtail on the fuel tank to work on that plug.
Good info, thanks. You happen to know what the pressure is when only one of the two pumps runs? I assume if the inline "high pressure" pump wasn't running, the pressure on the rail would be less than 40.
On mine for example, the Lpump would run for about 20 minutes, until that plug got hot becuase of the faulty connection. When the Lpump did not work, then there was no feed to the reservoir for the Hpump. The Hpump was trying to pull from the tank, it would barely run, the fuel pressure was a sketchy 8-10 watching it on the guage.
