[sah]

Newbie here with a question. Bought a two inch 4 hole spacer for an f350 with a 460. First off to help with vapor lock and secondly for some more low end. Problem is now after driving for about 10 minutes or once it gets to operating temps it dies and wont restart until it cools, then repeats after warming up. With the insulating wrap and carb spacer the fuel isn't hot anymore and the carb is only warm to the touch. So I am at a loss as to what it is. This is a new problem since installation of the spacer. Maybe I need to rejet? Any advice would be greatly appreciated. On a better note I have to say the spacer makes an awesome improvement in throttle response and low end. It will be the best 30 dollar improvement for the money if I get the problem solved.

[Deman625]

sah

I also have a f-350 with a 460 that Im getting ready to put the 4 hole 2in spacer on to get more low end.I don't know the answer to your question but I will see if I cant get you some info and I hope I don't have the same problem that you are having.If you find out whats wrong.Your info would be appreciated.


Good Luck
deman625

[Siggy_Freud]

Have you removed the spacer to see if the problem persists without it. Doesn't seem like a 2 inch spacer could cause a problem like that.

[blndweasel]

If you have an electric choke on the carb, check the connections.

hope this helps

tbw

[Ktaves1971]

it's got to be icing up. Try jetting up for more fuel. Please let us know what happens. I am also ready to put one of the 4 holers on.

[lluciano77]

You won't necessarily get more bottom end from a 4 hole 2" spacer. The four hole spacers will increase bottom end response sometimes. There are no guarantees. The 2" spacer will add more plenum volume. More plenum volume = higher RPMs generally. My point is, you could be doing more harm than good by adding the spacer.

[crazy larry]

which ignition system are you running, what year? i don't know about the eecIV or newer stuff, but i do know the durasparks' module will cause that symptom.

[rj57]

If you're already fighting vapor locking I've never heard of a carb spacer helping reduce this?

Most vapor locking starts at the fuel pump.

This could also be why it stalls and will only starts when cool. Vapor locking.

A few car buds and even myself had vapor locking problems over the years that was only cured by a new fuel pump.

The old pump wasn't strong enough to push past the vapor locking so the fuel got even hotter, some times to boiling point.

[lluciano77]

I have only witnessed vapor lock in Ford fuel pumps. The carb is an unlikely source.

[Deman625]

Originally posted by lluciano77
You won't necessarily get more bottom end from a 4 hole 2" spacer. The four hole spacers will increase bottom end response sometimes. There are no guarantees. The 2" spacer will add more plenum volume. More plenum volume = higher RPMs generally. My point is, you could be doing more harm than good by adding the spacer.

The guys at demon told me to put the four hole spacer on to help get my carb tuned in because I couldn't get my idle mixtures screws to respond. I have tried every thing that my manual said and nothing works so I called them and that is what they told me to do.Do you think that is a bad ideal if so let me know I got to much money rapped up in the motor to hurt it.


THANKS
dEMAN625

[lluciano77]

The guys at BG told you that?

If the mixture screws aren't setting up correctly a spacer won't help.

If you can turn them in all the way and the engine will still run, you have a fuel leak.

Check for blocked passages also.

[Docs91RS]

Originally posted by Deman625
The guys at demon told me to put the four hole spacer on to help get my carb tuned in because I couldn't get my idle mixtures screws to respond. I have tried every thing that my manual said and nothing works so I called them and that is what they told me to do.Do you think that is a bad ideal if so let me know I got to much money rapped up in the motor to hurt it.


THANKS
dEMAN625

Assuming the carbs floats are correct and the fuel pressure is right....chances are if you cant get a lean drop with the idle mixture screws your idle air bleeds are too big...without the equipment, knowledge, or luxury of experimentation the best approach is to drill a small hole ( cant remember exact size at ther moment) in the primary throttle blades. You must drill the hole on the front side of the blades.

P.S. If its a demon it most likely has removable idle air bleeds and smaller bleeds are available from demon

[scumdog]

Check two things, one that because your carb is now higher that the fuel line is not stretched too much and/or is too close to the engine and heat.
The other is check you float level (buy and fit a clear float-level plug to make it easier).
I had a brass float that had the most microscopic hole, if I set the float level it would be o.k. for a week or so and then it would run rich as the float sunk a bit - and when the engine was cold the rich mixture did not show up, just like your problem.
This drove me mad for years until I discovered what the problem was.

[Tech @ BG]

If the idle mixture screws do not have any affect they butterflies are out of position. Installing a 4-hole spacer will increase the air velocity through the carburetor which should allow the butterflies to be closed further, giving better adjustment of the mixture screws.

The spacer should help with that, but not with a vapor lock situation. Have you removed the spacer to see if the problem persists?

[78 monte]

I agree that a vapor lock will more than likly happen befor the carb and that the spacer is not going to help a vaporlock.Also on a chevy SB I've never heard of it being the actual pump being the source of vaporlock,its usually something stupid.
Have you checked to see that your fuel lines either befor or after the fuel pump are not to close to a header or something??
Get that straight then see if you can adjust the idle mixture.
From the sound of it,that it stalls after running for 10min says vaporlock still,to me anyway.