Electric fuel pump?

[DItR]

We have a 1987 Travel Master with a Chevy 454. We've had trouble with it vapor locking. I put in an inline electric fuel pump right above the fuel tank and left the mechanical fuel pump operational. Figured just switch on the electric pump when we start having trouble and to help it start quicker. Well I discovered that the fuel line is a 1/2" & the only pump I could find quickly was a 3/8" but I went ahead and tried it. Still having trouble and I wonder if the 3/8" pump is hurting it but trying to find a 1/2" inline fuel pump has been difficult.
So my questions, is the 3/8" inline fuel pump hurting the fuel delivery? Is finding a 1/2" inline fuel pump possible? What have others done to combat vapor locking? I know about wrapping the fuel lines up by the engine and plan on doing that but what else have people done?
Greatly appreciate any help. My wife is itching to use the RV.
John

[dougrainer]

Years ago, (1977 thru about 1986) on both Chevy and Dodge Class A chassis's, the Motorhome OEM's put a electric fuel pump to prevent vapor lock. BUT, the main thing they did for safety was to power the electric fuel pump thru a additional oil pressure switch. NO oil pressure, NO electric fuel pump. They did NOT remove the mechanical pump. They used the Oil pressure switch to prevent the fuel pump from operating if the engine died(accident or breakdown), so no excess fuel could flow. Doug

[Passin_Thru]

The 454 also has a screen at the Carb intake & fuel line connection.

[vegasfoodguy]

DItR wrote:
We have a 1987 Travel Master with a Chevy 454. We've had trouble with it vapor locking. I put in an inline electric fuel pump right above the fuel tank and left the mechanical fuel pump operational. Figured just switch on the electric pump when we start having trouble and to help it start quicker. Well I discovered that the fuel line is a 1/2" & the only pump I could find quickly was a 3/8" but I went ahead and tried it. Still having trouble and I wonder if the 3/8" pump is hurting it but trying to find a 1/2" inline fuel pump has been difficult.
So my questions, is the 3/8" inline fuel pump hurting the fuel delivery? Is finding a 1/2" inline fuel pump possible? What have others done to combat vapor locking? I know about wrapping the fuel lines up by the engine and plan on doing that but what else have people done?
Greatly appreciate any help. My wife is itching to use the RV.



John

You should take the mechanical out of the circuit, if the pump fails, you will get fuel (lots) in your oil.

Terry

[Executive45]

Wrap the fuel line and your vapor lock will go away. Fuel delivery won't fix it...Dennis

[Jim]

I remember the I/O lines of the external pump I installed on my diesel (right near the engine in the rear - fuel tank in the front) was a different size and I did worry about it a little. So I made sure the hose adaptors were right at the external pump, making it a short haul at the reduced diameter.

It's been 11 years so far.

Diesels don't get vapor lock so can't help with that. It's just I don't think your external pump has anything to do with it.

[enblethen]

I believe the carb 454 engines have two fuel filters. One in the carb fuel line intake and one on the frame rail near the rear axle.
The 3/8 line is norm. It is measured inside.

[path1]

I had problems on 84 ford, (still using carb, not sure about yours) and after many guesses and frustrations someone referred me to these.

Solved my problem and was pleased for many years after installing.

I picked it up at an auto part store. If I remember right it was best to install closet to fuel tank as they like to push gas instead of suck. Supposedly if it ever breaks it will still allow fuel to pass by and it did make a little ticking noise.

http://www.facet-purolator.com/

and within their site I got a very small one like this

http://www.facet-purolator.com/cube-fuel-pumps.php

I always checked the hose clamps were tight every oil change.

Good luck

[dakdave]

I have never seen a chevy with any thing bigger than 3/8 fuel line.Even the 2 1/2 ton farm trucks only had 3/8 line.
Are you sure this a vapor loch problem and not ignition related ?
How you have it hooked up should not be a problem

dave