Hope someone can help my 75 yo hubby, he isn't a mechanic but he is trying! Anyway we bought this Diamond 23' ford 460 , we drove it home , about 38mi, filled both tanks because they were empty,all was ok, then last week we were going to camp for weekend and got 62 mi from home when it started acting like it had a vapor lock, when I tried to go from 40 mph to 60 , didn't matter which tank I used. People have told him to remove the fuel filter in line, punch it out and put it back on, so he did that plus put a bigger one between tank and the smaller one (as is, not punched). Still won't stay running, chokes out quits. Then he was told to test if fuel pump was working, he removed one end of it and I turned on ignition( wo starting) he got a pint of gas in 20 seconds. Still runs for few min's then dies, I told him I read on rv site that he should open gas filler caps, that helped some , ran a little longer and a little smoother at idle, but died again. Now he borrowed a fuel pressure pump tester and he said it reads right at about 3 on the gauge that is numbered 1-10????. At his age I am praying he doesn't have to drain both tanks and replace pumps in them. There was a huskyhauler on the rv site that said something about buying a Bosch wiring harness and requiring somehow to just the oil pressure regulator and the inertia something and that the problem was because of the bad design of the 460 fuel thing being connected to the ignition????? If this is true is there someone that could give a diagram or picture of how to do that, he borrowed a chilton book but it doesn't show him where those things are or even how to do it, any other ideas would be so very much appreciated, we can't take it to a shop, we are on limited social security now. Sorry this is so long, it is all I know for now, thank you so very much, Barb. OH, the hot cold temp guage doesn't work, how to fix it

 

What year is the motor home?

 

It is a 1983 Diamond

 

1983 Diamond

 

A 1983 is not going to have pumps in the tank, you have 1 fuel pump mounted to the motor that sucks the fuel from the tanks and sends it to the carburetor , Vapor lock happens when the fuel under the hood gets really hot and doesn't flow anymore, unless you are driving in the desert I don't think it is vapor locking. A couple things I can think of is first make sure the choke is opening on the carb, if it doesn't it will choke out the motor and it will quit. Second you cannot test fuel pressure on a mechanical pump by simply turning on the key. you have to turn over the engine and see how much fuel sprays out of the line going into the carb. My hunch is you either have a weak fuel pump or the choke is sticking, The other thing it could be is the ignition module mounted on the distributor, they get weak and can cause these symptoms..

 

Hubby says the choke opens and someone put an electric fuel pump in on the frame rail about 2' from gas tank. You can hear it running when you turn the key on.

 

Is there a fuel filter on the inlet to the carb? Sure sounds like lack of fuel...3 psi is good for a carburetor. The pumps are in the tanks..The carbs need to be rebuilt or cleaned/replaced on these older engines..Power valves go bad in them.


Dick

 

I forgot to say thank you for telling me there aren't any pumps in the tanks, whew! Now I know he probably won't have to drop those tanks. Do you know anything about the retire thing, it said the way they wired the 460 it was wrong ?

 

Yes, hubby took the little one off and replaced it, after he punched the center as was suggested by friend he also put larger line filter between tank and the little one. Bigpipes35 just said there weren't any pumps in tanks, you say there is, very confused now??????

 

you might be able to hear them by turning the key on. Don't know for sure as these things are built different sometimes. If you got 3 psi and flow with key on then they are electric and in the tank..Pump on frame sends fuel up front..Still might be pusher pumps in the tanks..


Dick

 

Ok, thank you for info, will tell hubby, he will probably have to learn how to get the carb off and learn to work on it, YIKES!!!!!

 

I would turn key on and let it pump about a gallon to see if it holds up...Be careful gasoline is way dangerous. If the flow remains good for a gallon or two then the supply is prob fine.
You are saying it doesn't really run now? Does it backfire through the carb when you hit the gas at times indicating lack of fuel? Does it stall? If it does can you pump the accellerator to keep it running? There are pumps in the carb/they squirt fuel into the intake. When the van stalls look into the carb and see if they are still working by pumping the pedal..If not the carb is empty of fuel.

 

Yes it backfires once in a while, yes it stalls and yes if you keep pumping the gas pedal sometimes it will keep running, take foot off gas and it dies, but, if you loosen gas caps it runs a while longer and a little smoother before it dies. I just read your post to hubby and he laughed in my face and said he can't even see the carb, it is up under the dash, this is a class c and even when he takes the engine house off inside the cab he still can't see into it

 

Bummer on the can't see thing...Wow how long are you going to be where you are at?
Be best to find a local mechanic to come and look at it. If I were there I would look at it for sure..Who ever you find should be above 55 years old LOL...

 

It sounds ignition related to me.