I just wanted to let anyone,who has one of these things on there van (e350 with a 460 in it,mid 80's), know about them.I'm certainly not the designer of these things but have learned alot about them(actually way more than I ever wanted to,lol) The first thing you'll think, it's a gas filter(it is about a foot in front of the carb and will be a tee).That will be your first mistake!The next thing you'll do is pull it off and blow into the end,then you'll bet you best buddy your favorite "blue tick hound" that it's plugged.Bye,bye doggie!!!!Yep,your wrong!!!Take some carb spray and maybe an air hose and try to clean it out,you probably won't notice any difference. Don't do what I did and try to punch the inside ball with a hammer and punch or return orfice thinking it's plugged,it ain't plugged and you'll just ruin it.There are no moving parts in it,just a screen that the spray should clean.After you've checked your in-line gas filter and fuel pressure(just unhook the line at the separator and let it pump into a jug to see if there's good pressure)check the filter in the carb and using an air hose blow out the return line(which will be out of the top of the separator,I'll call it a "tee" from now on) and maybe gas line to the filter at least.If you have good pressure and the pump is running in the start mode and the run mode(yes there are 2 separate circuits),I'd try rebuilding the carb and floats first.I found an aftermarket tee lets to much gas to the carb and floods it out and to be quite honest nobody at an auto parts will have any idea what your talking about and will try to sell you everything but the tee.The original tee is only available from Ford and you'll need to know what size you have,if your lucky your old one will be color-coded,otherwise they go by the size of the return orfice EOTZ 9N176-b is the .090 size.E3TZ 9N176-a is the .060 size.E3TZ 9N176-b is the .040 size.They run about $55.00 each. The problem with my van ended up being a broken wire from the oil pressure switch to the fuel pump relay.

 

I just needed to put a few tidbits of info that I forgot.The first is I'm not exactly sure I have the right fuel pump,the previous owner put a new one in,so I'm not sure of the pressure rating for it?He took the old one out and set it on the counter at a local auto parts and they gave him a replacement,so I am assuming it is the correct one.The second is,you need oil pressure for the pump to run in the run mode,that is what the oil pressure switch is for.

 

Here is some phots by aldog.

 

Here are two diagrams of the wiring of this fuel system.
The first shows the oil wire that aldog was talking about.

 

> The problem with my van ended up being a broken wire from the oil pressure switch
> to the fuel pump relay.

Yes, a step that gets over looked in the newer EFI vehicles. Which can be a real hassle for the vehicles where the wire is mounted low and open to road debris and salt or branches off road.

 

His Van did not have EFI.

 

Hi Aldog

Your post sounds like it may address our problem. I just posted this-

My new (to me) 1996 Ford 350 24 foot motorhome with 460ci engine & 77,000 miles lost power very suddenly after running normally for around 4 hours on a trip to Denali Park from Anchorage. It began on acending a mild incline at 65 mph. Power continued to drop away as the transmission downshifted with falling speed as though the engine could not take more trottle under load and began to backfire.

The engine idled normally at pull-over. After a 20 minute shut-off, it started and ran normally for another hour to our destination. Outside air temperature was in the 50's. The temperature gauge was reading about 1/3rd; well below the center point Normal operating range. We were not towing and this is a small 24 foot, light MH. Same thing on the return trip. A retired mechanic recalled this was a common problem for MH renters in 1996. A small exhaust leak (Piff Piff sound) can be heard in the cab at low speed, through the cab engine cover; can't see an obvious source.

Does this sound like the problem you discovered? Would replacing the Fuel separator fix the problem?
Thanks
<!-- / message -->

 

I am not Aldog but a 1996 does not have the fuel (vapor) separator.
They were used on Carbureted 460 engines from about 1982-1986.
Sounds more like you fuel pump is on the way out.
When the fuel gets between 1/4 and 1/2 the pump can heat up and can go out in time.
The small exhaust leak (Piff Piff sound) that you hear could be a cracked manifold or a rusted out exhaust manifold gasket.

 

I realize this is old post. In case if 'Aldog' is still around. I wanted to say "thank you"

For anyone who maybe interested, here is a link to picture of item

https://skydrive.live.com/redir?resi...=folder%2c.jpg

 

Cool. Thanks Dan!

 

I did a stupid thing...but let me go back
I purchased a 1986 Motor Home that was built on an E-350 chassis, naturally with the 460 - 4 bbl in it. I was originally having a problem with getting gas from the tank so I cut out the fuel vapor separator to gain access to the fuel line to the carb...ran an external elec. fuel pump to an external gas tank to get it to its permanent parking spot. Now I decided that I want to move the Mobile Home, so I replaced the fuel pump in the gas tank, which works great now, but I am getting gas leaks from all different places, from the vapor canisters, even back thru the carb. After much searching, I find out that all this could be prevented by the vapor separator, which I no longer have. I have two questions....First - can you remove the fuel vapor separator system from the truck? and bypass the canisters and all? If not, where can I purchase another vapor separator? Most parts stores have no idea what your talking about, even after showing them a picture of it. If I replace the separator, will that stop all the other leaks in the system?

 

Sounds like you have way too much fuel pressure.
The vapor separator was put on to stop vapor locking by keeping the fuel moving all the time in the fuel lines.
No the vapor separator will not stop your leaks.
Yes you should be able to order a vapor separator from a Ford dealer.
Just give them the part number of orifice size you want or search for it on the internet with the part number.
Part numbers are in the image below:

/

 

If what you are saying is true, by placing the separator back into the circuit, it will not stop the excessive fuel flow to the carborator. Then how do I go about limiting the fuel flow to the carb. The fuel pump that was replaced in the tank is to OEM specs.
According to all that I have read about this unit, it is also supposed to channel back excessive fuel to the tank as well....I guess I will find out when I install a new unit.

Thanks

 

Now I could be wrong but all the cars/trucks that I worked on that came with a carb used a mechanical fuel pump. Did yours have one?
If you installed/replaced the electric pump inside the fuel tank it may have to much pressure. You need to get a gauge to measure how much.
Since you have a carb, they usually only need a max. of 6-8 psi to operate correctly and some carbs need less. If the pump you have puts out to much you will need to install a fuel pressure regulator to control it.

 

Thanks Jim for the info...First let me say that this is a 26' Motor Home and the fuel pump was in the tank originally...now. I purchased the replacement pump to "OEM" specs....what the exact fuel pressure is, I don't know. What is required for the carb to work properly, I don't know that either, but it is the orginal 4-bbl that was on it. Where can I find these specs? Right at the moment, I'm waiting for the fuel vapor separator to get delivered so I can install that back into the system and then see what happens. This is also supposed to channel back any excess gas going to the carb, back to the tank. Hopefully, it will do that and then problem solved. If not, then I have to check, like you mentioned, fuel pressure and then go from there...
Boy...give me a good ole 390, or even a 427 (ford) anyday