EFI Fuel/Return Problems

[S_bolt19]

I am having major problems right now with my fuel delivery/return. What is happening is that I have EFI and I keep overflowing the spare tank. What I have on this is as follows (from tanks to engine): Original fuel tanks (main & aux.), filter, 6 port fuel selector valve, fuel pump, engine. Everything is run together through rubber hose (both feed and return lines). Every time I run off of the main tank it returns fuel to the spare tank. When I run the spare tank it also returns to the spare tank. I have switched the return lines at the selector valve a couple of times but the same problem occurs. The selector valve has been replaced 2x and the problem is all the same. What would be causing this. I am at a loss for what to do, I am basically ready to rip the entire fuel delivery system off and start over so that I know what the h*ll is going on.

Just for the record, I didn't put the EFI system on, I had it done because I didn't have the time on my hands when I needed it. The engine had 350k on it died when I had the work done. So this problem isnt my fault..... [-X

Thanks for any help

 

[STLKIKN]

I don't know how the six port selector switch you have works or switches ( I don't have it in my curious little hands to play with it....)

BUT, for a quick and easy holdover until you can repair it, how about running off the aux tank until it is empty??

Think of it as a built in reserve... run aux until empty, run main until it is empty, then switch back to aux and drive to gas station on "return" fuel....

edit...

Could the selector be hooked up backward to flow??

return should be one in and two (switched) out....

if you put the return (from engine) to the port currently hooked up to your aux,

what happens to flow when you switch the tanks??

 

[S_bolt19]

The way this thing is set up, and I was looking at it yesterday afternoon, is the switch is a cheapo thing with a 1 wire hook up to an on/off toggle switch on the dash. So essentially if I am looking and reading the set up right, in the "on" position it should be supplying/returning fuel to 1 tank and in the "off" position it should be doing the same for the other tank. I have traced out the return lines and they seem to be connected to the correct "feed" tank but the problem is that the return fuel always goes to the aux tank. Even if I have it switched to the main it will still return to the aux. Anyway, I talked to an EB guru yesterday who has put EFI in about 50 EBs and he said that it sounds like the switch has gone bad on me.

What I should do is just scrap the whole 6 port system, break down and bite the bullet for a 23 gal main tank. That way I dont have this stinking problem anymore and I can eliminate the spare all together. I mean, shoot, the main only holds 12-13 and the spare only holds 7-8 gallons so I would be better off with the big tank anyway. The only problem is that $400 price tag right up front....OUCH!!

 

[BASE861]

What kind of tank switch are you using? Is there a single wire that switches polarity attached to it or are there two wires? Are you controlling it through the stock switch or by a different one? I am thinking that if you have a tank switch that changes the feed and return seperately then one might get stuck open and not allow the fuel to return to the proper tank. This might be caused by incorrect electrical work.

A 23 gallon tank would rule. But for that much cash I will hang close to the pumps.

 

[Leo]

What I should do is just scrap the whole 6 port system, break down and bite the bullet for a 23 gal main tank. That way I dont have this stinking problem anymore and I can eliminate the spare all together. I mean, shoot, the main only holds 12-13 and the spare only holds 7-8 gallons so I would be better off with the big tank anyway. The only problem is that $400 price tag right up front....OUCH!!

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True, but man it makes things so much easier. Don't forget that you'll need to route new lines (I prefer steel ones, myself) you'll need a low pressure and high pressure pump, and an accumulator. Not to mention, it's a good idea to get the skid plate for the tank, and run a needle valve on the return line (cheap part). Yeah, 400 is kind-of low-balling that mod. >-

It's well worth the effort though. Nothing like getting that aux tank out from under your ass, as well as only having to fill up one tank.