Bullnose Enthusiasts Forum

Rear tank fills up front tank

Classic

List

Threaded

35 messages Options

Howling.Wolf

Rear tank fills up front tank

This post was updated on .

CONTENTS DELETED

The author has deleted this message.

´86 F150 5.0 EFI 4WD LWB
I belive in metrics. 😉

Gary Lewis

Re: Rear tank fills up front tank

Administrator

Heinz! Good to hear from you. How is Oberursel?

Sorry that you are having that problem.

I think you may have a problem with the tank selector valve. I've seen it before where it doesn't switch properly and returns fuel to the wrong tank.

In the page below you can see that valve. So I would check to make sure it is getting the voltages it is supposed to get, although if the right pumps are working then it should be.

Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

Howling.Wolf

Re: Rear tank fills up front tank

Hello Gary,
good to hear from you and hope you all get around this stupid Covid-Virus.
Thanks for asking we are good here in Oberursel, life slowly becomes some kind of normal again.
Exept wearing the masks in shops and travelling outside of Europe

Thanks for the hints but I just cannot imagine where that tank selector could be.
My Bullnose got a fuel reservoir with filter instead (see pic but with 4 inlets)
If yes, there then is nothing to switch. But yes there are valves working pressurewise inside.

Best regards

Heinz

´86 F150 5.0 EFI 4WD LWB
I belive in metrics. 😉

Gary Lewis

Re: Rear tank fills up front tank

Administrator

Heinz - Sorry, but you apparently have the later version of the fuel system. The earlier version is shown in the first illustration and the later one is below that. (I'd much rather use Ford illustrations that LMC's.)

I don't understand how the later system works. I say that because I don't see how it knows which tank to return fuel to w/o the tank selector. Unless it uses different in-tank pumps with check valves. Maybe Bill/85lebaront2 knows? I'll tag him.

Gary, AKA "Gary fellow": Profile

myrl883

Re: Rear tank fills up front tank

In reply to this post by Howling.Wolf

This is all too common of a problem. We used to deal with it at the dealerships pretty frequently.
Your '86 should have a reservoir (9K044/9B263) with 6 ports, unless someone added a second tank and teed the lines together. The cause of your problem if all is plumbed correctly is the fuel reservoir.

Now, to answer Gary's question. On the newer trucks that have a "fuel delivery module" in each tank, the check valves are built into the modules. When this problem occurs, the tank receiving fuel at the wrong time has a failed valve, and you need to add an inline check valve (there was a recall on this) or replace the fuel delivery module. Trucks with FDMs can be identified by a 4 line reservoir, and the front and rear fuel lines teed together between the tanks and the reservoir.

Ford Parts Monkey since 1985
1981 F100 Flareside - Black, 302-4V Roller/AOD
1986 F150 Flareside - Medium Fire Red 302/AOD
1989 F150 Standard Cab 4x4 - Dk Shadow Blue 302/AOD
1993 F350 4x4 Crew Cab - 7.3 IDI/ZF-5
I think it's a sickness...

85lebaront2

Re: Rear tank fills up front tank

Administrator

I do have a question, where would the reservoir be on a 1990 F250 with a 7.5L engine. All I found were fuel lines from the tanks to the filter and then the engine. There are a pair of tees outboard of the forward tank that all the lines go through.

There was indeed a recall, TSB 01M05 and is on this site here: https://www.garysgaragemahal.com/fuel-cross-flow.html

Bill AKA "LOBO" Profile

"Getting old is inevitable, growing up is optional" Darth Vader 1986 F350 460 converted to MAF/SEFI, E4OD 12X3 1/2 rear brakes, traction loc 3:55 gear, 160 amp 3G alternator Wife's 2011 Flex Limited Daily Driver 2009 Flex Limited with factory tow package Project car 1986 Chrysler LeBaron convertible 2.2L Turbo II, modified A413

Howling.Wolf

Re: Rear tank fills up front tank

In reply to this post by myrl883

I guess you are right.
My reservoir has 4 ports in and 2 out.

I will 1st check if I conneced the rear tank the right way. 2nd take it (the reservoir) off and see if I can do anything about it.
I keep you updated.
Thanks so far

Heinz

´86 F150 5.0 EFI 4WD LWB
I belive in metrics. 😉

Gary Lewis

Re: Rear tank fills up front tank

Administrator

In reply to this post by myrl883

So the FDM's actually started in '86? I wasn't aware of that and haven't found it in the MPC. Apparently the base part number changed from the sender/pump combo so I need to look elsewhere.

Gary, AKA "Gary fellow": Profile

85lebaront2

Re: Rear tank fills up front tank

Administrator

No, Gary, they didn't, there was some confusion in there.

On the reservoir/tank selector valve, the ports for each tank are paired, from the picture it would be top two to one tank, bottom two to the second tank. Front pair, large to Bosch pump on the frame, small is return from engine. This system was used on all EFI trucks (Broncos only have one tank) through 1989.

1990 on use the FDM and many trucks from that era will have the recall check valves installed.

Bill AKA "LOBO" Profile

Gary Lewis

Re: Rear tank fills up front tank

Administrator

Thanks for the clarification, Bill. I didn’t think the FDM came out in 86, but wasn’t sure.

Ford sure tried a bunch of different systems in that era. Makes it very confusing.

Gary, AKA "Gary fellow": Profile

85lebaront2

Re: Rear tank fills up front tank

Administrator

I was trying to find the picture last night, but wasn't having any luck and it was already after 11 PM here.

Bill AKA "LOBO" Profile

Howling.Wolf

Re: Rear tank fills up front tank

This post was updated on .

What I find strange is, that those replacements are meant to be for Trucks from 1989 onwards.

´86 F150 5.0 EFI 4WD LWB
I belive in metrics. 😉

Howling.Wolf

Re: Rear tank fills up front tank

Hi,
I swopped (not very professional I know) the into the Reservoir/Valve comeing lines.
At the moment (hope I am not saying this too early) it looks allright.
Anyway I want to thank you guys for your efforts. And I sincerly hope you all are staying healty.

All the best

Heinz

´86 F150 5.0 EFI 4WD LWB
I belive in metrics. 😉

Gary Lewis

Re: Rear tank fills up front tank

Administrator

I hope that works perfectly! Good luck.

And here’s hoping you stay safe as well. Things are getting worse here in Oklahoma due to the virus.

Gary, AKA "Gary fellow": Profile

Howling.Wolf

Re: Rear tank fills up front tank

Thanx Gary,
Viruswise, the Deltaone is bad, I know a youngster who was vaccinated and got it.
But because of the vaccine he was good after 2-3 days.
So that gives all of us hope, as the most of us are (if not almost all here in the district) through and got the 2 shots.

Bless you and haveaniceday.

Heinz

´86 F150 5.0 EFI 4WD LWB
I belive in metrics. 😉

Gary Lewis

Re: Rear tank fills up front tank

Administrator

Glad to see that you've had the vaccine, Heinz. My wife and I've actually had our third shots, the booster. She's immuno-compromised and so qualifies for a booster. And since I live with her, I qualify as well.

Gary, AKA "Gary fellow": Profile

Howling.Wolf

Re: Rear tank fills up front tank

Alle the best For you And your wife. Lets get rid of this stupid virus all toghether, please.

´86 F150 5.0 EFI 4WD LWB
I belive in metrics. 😉

Gary Lewis

Re: Rear tank fills up front tank

Administrator

Thank you, Heinz. And I agree, let's get rid of it!

Gary, AKA "Gary fellow": Profile

Howling.Wolf

Re: Rear tank fills up front tank

This post was updated on .

In reply to this post by Howling.Wolf

Uups,
allright just swopping the lines did not solve the problem. It only worked as long as the front tank had some fuel (switching front rear seemed to work).
What a bummer !
The car almost died when switching to rear while front is emty.
So I switched the lines back as they used to be, and probably have to buy a new valve with filter as shown above.
Or do you have any other options in mind ?
Haveniceday
Heinz

´86 F150 5.0 EFI 4WD LWB
I belive in metrics. 😉

Gary Lewis

Re: Rear tank fills up front tank

Administrator

Bummer! But I think you've proven that the valve is bad, so I don't see that you have any reasonable alternative but to replace it.

Gary, AKA "Gary fellow": Profile