1987 GMC V1500 5.7 TBI fuel tank selector valve ??

[NastyBuzzard]

Ok so I'm having problems with my truck. Have a good long forum going on on 88+ thread. I've got hesititation/stutter/misfire under load.

Took fuel pressure and got 18-19 psi on supply line while running.
Took fuel pressure for return line and got 20 psi while running.

Checked everything and it ended at selector valve (6 port). No fuel was getting past return port on the valve back into the tank.

Now I'm looking to purchase one. Found PN FSV1 (49.99)(3 port) and FSV2 (62.99)(6 port)

Even though it says 3 port it looks like The just the 6 port but with like vacuum caps on the other 3 ports. Anyone have an ideas on this???

[Prong]

You'll need a 6 port valve to accomodate the fuel return lines. I believe the valves for 87's are year specific because of the fuel injection.

[NastyBuzzard]

Yeah I got that but if you look at a picture of the 6 port and the 3 port, both have 6 ports just one has rubber caps over the 3 return line ports and other than that they look exactly the same only around $15 difference

[87 STEPPER]

For 15 bux more just buy the 6 port one. Im gonna tell ya the valving is different internally for the 3 port and it's for a carb'ed eng. and it wont handle the fuel press of fuel inj.

[NastyBuzzard]

The $15 more valve says its rated at 65PSI max and the other is rated 60PSImax.

I took my old one apart today and cannot see anyway that the part can be made differently than it already is. It has a small DC motor in it that drives two piston like valves to open and close both sides of the ports. Both of those sides would have to operate just like the 6 port on the 3 port to switch pressure lines from each tank.

Just seeing if anyone has ever tried it...

[NastyBuzzard]

Both parts showed up at auto parts store. Both looked exactly the same except one had 3 vacuum caps on the 3 return ports. Took cap off and blew and air came out same side as supply side. Also had same part numbers listed on the actual parts...