Hey guys. I got a 63 deville 2dr series 62 without AC. Im positive what im experiencing is vapour lock. Ive experienced it twice in the month ive had the car. First time it died on me after cruising around for an hour. Keep in mind it was a really hot day. But the car stalled out and died. I waited like 15 mins, lugged it out of the way. And when i came back hour or so later it was fine.

When the car is cold and i first start it the fuel filter bowl is full of fuel. After cruising i always see the fuel low, down to the bottom of the filter, and its always bubbling away even when the car is shut off. I used a temp gun last time it happened and the temp around at the fuel lines were at like 200°f. I have put a garden hose on the fuel pump while it was running and the fuel would raise and fill up the filter bowl.

I recently changed the thermostat down to a 160° and changed the coolant out. The cooling system seems to be working fine.

I heard adding a return line back to tank usually will solve the problem. Im trying to find a glass filter bowl off a AC vehicle at the moment. But i did some more research and found that sometimes the heat riser sticks. But my car has true dual exhaust and i think it has been removed. I couldnt find it.

The lines look to be routed like original. Does any one have any pictures of how the fuel lines are routed in the engine bay for AC and non AC cars?

Thanks guys. Any help or suggestions is appreciated.

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what is the second easiest and less dangerous,  so as not to continually pump?? or is the switch your savior, assuming you can reach it in a accident.

Hey russ. So what did you do with the steel lines that are hook up to the mechanical pump. Did u cut the ends off and attach ends with rubber fuel hose?

To put a hose on the end of the stock fuel line, I got a fitting from the local hardware store and screwed the fitting onto the stock line. The fitting has a barbed end to attach the hose.

have u ever used the carter rotary vane pump?


i guess its easier to route the hoses with the one you suggested?

Gutted - means he removed the internals of the mechanical stock pump so fuel can flow thru it from the electric pump on one of his cars
He removed the mechanical pump on the other car completely and replaced it with a metal plate from a chevy engine to seal the stock pumps hole in the engine
So there he is only using the electric pump directly from the gas tank to the carb
He modified the gas lines that went to and left the stock mechanical pump

All AC equiped cars came with a return line from the glass fuel bowl back to the gas tank
That return lines purpose is to prevent vapor lock which is what this tread is about preventing

Hope that helps understand the terms used
Always good to ask questions about what you do not understand

Remember there are never any dumb questions if the question asked help you understand something you have a question about
There is a definite leaning curve to this car stuff and we all started the same way you are starting out - by doing asking questions and learning

Studing the service manual for your year car cover to cover ( like a college final exam ) will be a very big help to understand your cars details

I need to do that again as it has been about 11 years since i last did that
Often we forget what we use to know or did about a subject as time goes by


i kinda figured that was what it was, but my thought was why do both ways,, was there a reason he chose to gut one, and remove the pump on the other?

I have the AC equipped version, however, at this time, it is not working,, at very least, the compressor is locked up, but have not gotten that.  

My questions are for future reference as if I can find a reason to make it run, ride and start up more reliably and not rely on 15 20 0r 25 year old pump,, I will get to it in short time.  

Does that return line  reliably prevent Vapor lock? does the compressor have to be working for that to function as well or is it an built in, function whether ac runs or not.  Looks like if it works 75-100 parts and time is well worth the outcome of reliability in very hot weather,  I use the car in MT, where even at 4,30 pm its 92 degrees, and back in MS where i also will use the car, 90 to 100s are the norm for months,,

My sedan has the gutted fuel pump, while the hearse has the pump removed.  Why?  The hearse fuel pump started to leak at the inlet fitting, and I wanted to see what it would look like without the fuel pump.

The fuel delivery and fuel tank return ( from the glass fuel filter ) line do not have anything to do with the AC working or not
Not sure if the return line prevents vapor lock myself
I have never had that problem and i am in very hot florida weather 1/2 the year
My return line has been disconnected for years with no problems

A mechanical fuel pump either works or it does not
So if yours is working as it should only deal with this issue when yours stops working
You may not realize you pump may have been replaced in the past depending on who owned the car prior to you

If it ain' t broke -Don't fix it !!! ( it rule number one with anything you are thinking of FIXING )


Pretty clear, i have a lot to learn about these cars and engines,, 

thanks for the information


If having a problem determining what may be causing a noise or a squeek etc in the car for example
My dad (one of the really Super Car Guys ) would say " Turn up the radio until it brakes and then you will find what the problem is "
I always though that was an interesting approach to auto repair


Well i got an update for you guys. I finally put the car back on the road its been like a month. I did install the electric fuel pump, and it works really good. Got lots of fuel in the filter bowl at all times. Runs good and hasnt died while it has been driven around....yet.

But one problem im having still is say when i go for a long drive on a hot day, sometimes stuck in traffic or whatever. When i park the car for like 10-15mins, and jump back in the car, it would make it down the road and again it would die exactly the same way it was dying when i had vapour lock before. After this happens i cant start the car until i let it sit for like 10-20mins. The last time this happened. I was looking under the engine at the fuel bowl before the car even shut down, I saw bubbling in there. Keep in mind the car was OFF at this point.

This makes me think that the engine is getting like a heat soak after its shut down. If its parked for longer amount of time its fine. Just when I shut it off for 10-15mins.

I didn't see a reply to checking the heat riser valve on the left exh manifold. If stuck closed, it will overheat the intake manifold.

What carb are you running?  A phenolic block is needed with the stock carburetor, and if yu are running an Edelbrock, a phenolic spacer is recommended. 

The car bay be running too lean, causing a heat buildup problem.



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