First I'm an old time mechanic been doing this for 28 yes but this 87 F150 has got me a little annoyed, she has some issues one is that first I was having fuel issues between both tanks, I've put in new pumps tank and rail, new tank splitter inline valve, fuel filter and up dated the switch according to Ford TSB for fuel tank issues from switching from one tank to other. Both relays are new all wiring is good new plug on rear tank, with old system before all updates only front tank would work , now with all updates only rear tank works, been that way now for a while done beating head against wall.
Second the top hose collapsed from T/stat repaired that now I have the old surge and want to die syndrome, has new plugs, cap, rotor, coil, egr is good been checked, now bought IAC, TPS, MAP, all vac hoses good will see if that does it and has hi mileage but not issue, just need some other ideas before I put dynamite in truck.

 

You say you put a new tank splitter inline valve on it. Could you explain what that is?

If you removed the fuel reservoir and replaced it with a fuel tank selector without a reservoir the that can cause "the old surge and want to die syndrome".

 

All has been changed to original equipment just all new parts even has new tanks, unless Ford screwed up and gave me the wrong inline splitter unit but looked the same as old and all lines fit correctly, na just a thought it wouldn't be that simple, but one never knows.

 

The surge and die syndrome is not part of fuel tank issue.

 

I have also heard that the canister line from the canisters can cause surging also.

Some have had bad computers do it too.
You may need to check the caps in it to see if they are leaking.