switching gas tanks?

[rjn72]

My 87 has dual tanks. When I bought it the switch was on the right tank. The previous owner said that the tanks used to alternate by the switch. However the truck sat for about three years. I have had it almost one year and every time I switch the tanks the truck dies. What would you guys check in the order of most likely to quit working. Solenoid under the truck or switch in the cab? Any other suggestions? Thanks.

[rjn72]

The truck only runs when it is on the right tank. Not sure if I made that clear. Thanks again.

[Big Port Jimmy 6]

TBI or Carb? If tbi bad pump possibly. Jay

[rjn72]

tbi. I would prefer to check somewhere other than inside the tank first though.

[Gordonr1973]

When mine did that I bought a replacement switch and worked my way back from there....it was in the tank for me though.

Did you try banging on the bad gas tank with a rubber mallet to get the pump working?

[mag68]

The switch in dash would be the quickest thing to eliminate but seems like it wouldn't be the switch. If that was bad i would think it would just be stuck on one tank. maybe bad pump or clogged line??

[rjn72]

The light came on. lol. If the switch wasn't working it wouldn't die. The gas gauge does not move when I switch tanks either though, and I just put 25 in gas in it, so I know it has gas. Should the gauge switch even if the pump is not working?

[Gregs71]

With the motor off, move the switch to the bad tank. Put your ear near the tank and have somebody turn the key on. You should be able to hear the pump buzzing/priming. If you hear the buzzing then its either the switch in the cab or the cross over under the cab. The cab switch is only 18-20 bucks. The cross over under the cab is harder to get to and more expensive.

[DetroitDan]

what if the fuel pump is on the motor? My 82 only works on the left tank, I havent dared try to switch it yet because I'm afraid it will hang up or something and I wont have anything working. So actually I dont even know for certain it is stuck, just going on what the p.o. told me. But he also told me it was stuck on the right tank. Put gas in it tonight for the first time, put 5 gallons in the right tank and the gauge didn't move, so I filled the left one and it went up. Be nice to have them both working.

My 81 used to work and I loved it, but one night when it was really cold it failed to switch over, although the gauge said it did. Flipped the switch, gauge went up to full on the full tank, but I kept running off the low one until it ran out. Tried to swap the fuel lines at the crossover, but I didn't have any pliers and just couldnt do it with my bare fingers. Long night.