1985 F150 4x4 5.0l Dual tank and pump connector schematic
11-02-2011, 08:24 PM
#1
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1985 F150 4x4 5.0l Dual tank and pump connector schematic
Hello,
I am wondering if anyone could help me with the connectors at each tank fuel pump? I just need to know ckt, pin# and function of each circuit. I appreciate any help you can give!
I am wondering if anyone could help me with the connectors at each tank fuel pump? I just need to know ckt, pin# and function of each circuit. I appreciate any help you can give!
11-02-2011, 11:16 PM
#2
Senior Member
Do you have EFI or carb engine?
What problems are your having?
I have posted extensive diagnostic and troubleshooting for the dual tank setup here including schematics. Search my username.
Edit:
Here are a couple of diagrams:
Clear drawing but the grounds at the tank senders are not correct.
There are 2 separate ground wires at each tank connector.
http://i608.photobucket.com/albums/t...FIfuel-sel.gif
From 86 shop manual:
http://i608.photobucket.com/albums/t...0/duelfuel.jpg
.
What problems are your having?
I have posted extensive diagnostic and troubleshooting for the dual tank setup here including schematics. Search my username.
Edit:
Here are a couple of diagrams:
Clear drawing but the grounds at the tank senders are not correct.
There are 2 separate ground wires at each tank connector.
http://i608.photobucket.com/albums/t...FIfuel-sel.gif
From 86 shop manual:
http://i608.photobucket.com/albums/t...0/duelfuel.jpg
.
Last edited by klricks; 11-03-2011 at 09:14 AM.
11-05-2011, 10:07 AM
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To answer your question I have Fuel injection...the issue I was having was long crank before startup and intermittant loss of power, also after driving, if i stopped and went into a store and came out-the vehicle would not start....if i shot starting fluid into the intake it would momentarily start.....after cool down for about 30 minutes it would start up and stay running.
I installed fuel pressure gauge, started it-it showed 35 psi but the gauge would jump alot and i could hear the high pressure pump-very noisy, I then listened at both tanks and could not hear either one running regardless of selector switch position-I even unplugged them both while it was running and it stayed running which I never thought would happen...so i checked power and ground at both pumps it was good so i pulled both pumps and was amazed at what i found. The vehicle had sat for about 4 years so i put "Stabil" in the fuel-well I found that to be a bad idea.....the strainer on the pump, the hose that attaches the pump to the tube and the rubber grommet on the other end of the pump were melted-completely-I couldnt believe it-so think twice before using that stuff. Also both brass floats had filled with fuel-keep in mind I had replaced the tanks and the pumps 4 years ago and was wanting to preserve everything until I finished other things I was doing to the truck-uh needless to say-bad idea!
Anyway, your schematic is exactly what I needed-thank you very much!
I installed fuel pressure gauge, started it-it showed 35 psi but the gauge would jump alot and i could hear the high pressure pump-very noisy, I then listened at both tanks and could not hear either one running regardless of selector switch position-I even unplugged them both while it was running and it stayed running which I never thought would happen...so i checked power and ground at both pumps it was good so i pulled both pumps and was amazed at what i found. The vehicle had sat for about 4 years so i put "Stabil" in the fuel-well I found that to be a bad idea.....the strainer on the pump, the hose that attaches the pump to the tube and the rubber grommet on the other end of the pump were melted-completely-I couldnt believe it-so think twice before using that stuff. Also both brass floats had filled with fuel-keep in mind I had replaced the tanks and the pumps 4 years ago and was wanting to preserve everything until I finished other things I was doing to the truck-uh needless to say-bad idea!
Anyway, your schematic is exactly what I needed-thank you very much!
11-05-2011, 02:42 PM
#4
Senior Member
I had the same problem with gummed up strainer and the disintegrated rubber connector hose on the sender inside the tank. The EFI engine has the in-tank pump with the rubber hose the carb systems do not.
As you found the engine will run without the in-tank pump. In my case the engine would starve and 'buck' at higher speeds and the HP pump whines.
I don't remember ever using Stabil in my truck. I do use it in my MC from time to time. Stabil claims their product does not harm rubber parts but anything is possible.
Another possibility is ethanol in today's fuels. Ethanol definitely causes problems with rubber parts. Just lurk in one of the marine or small engine forums.
Also octane boosters have allot of alcohol which is bad for rubber parts.
As you found the engine will run without the in-tank pump. In my case the engine would starve and 'buck' at higher speeds and the HP pump whines.
I don't remember ever using Stabil in my truck. I do use it in my MC from time to time. Stabil claims their product does not harm rubber parts but anything is possible.
Another possibility is ethanol in today's fuels. Ethanol definitely causes problems with rubber parts. Just lurk in one of the marine or small engine forums.
Also octane boosters have allot of alcohol which is bad for rubber parts.
