Vapor Locking Apache


I have a 1960 Chevy Apache, 6cyl w/what I believe is a vapor locking problem. I drive about 10 miles and it starts to spurt and shudder as if it is getting no gas. I let it cool down and it starts right up, goes a few miles and it does the same thing again. I’ve re-routed the gas lines away from the head and over the valve cover to the carb, but same thing happens. It was only 40 degrees out today, and it is still giving me grief. Help!

Thanks Joe and the vapor locking Apache


Maybe the coil is getting hot?


Vapor lock usually keeps a car from starting up but doesn’t usually stop it when it is running. Look at the fuel line and if it is too close to something hot on the engine, reroute it by bending it. If you can’t bend it, insulate it with a fuel hose over the line or heatproof gasket material held on with steel wire. Ok, I see you tried that. It could be that the choke isn’t opening if it is an automatic choke. The other problem could be that the float level is set too low. And as mentioned before I said it; if the coil is getting hot, replace it.


Have you confirmed that it’s vapor lock by looking down the barrel and manually activating the accelerator pump (via the throttle linkage) when this happens? If it’s truely vapor locked the float bowl won’t be full and pressurized and the spray from the accelerator pump should be absent.

I too am wondering whether it’s the coil. Checking for spark when this happens might also bear fruit.


Other possibilities could be a faulty ignition condenser or the gas tank vent is plugged; the latter which may be allowing the pump to attempt to pull fuel from a vacuum inside the tank. Either one of those, along with the coil suggestion, may allow the vehicle to run fine after sitting a bit.
I’m not convinced this is a vapor lock problem; especailly this time of year.


This is the classic symptom of water in the fuel filter. Let it sit for a minute with engine off and the water drops off from the filter paper drive a little and it re coats the paper. Might be time for a new pump.


Thanks for the great suggestions. I’ll try replacing the coil and I have now insulated the gas line and replaced the gas cap. I’ll go from there and replace the fuel pump if necessary. Thanks again, Joe and the Apache.


I am putting my money on a bad fuel pump. Before you purchase a new coil, which may be needlessly, I would check for spark getting to the plugs while the trouble is happening. The easiest way to do that may be by spraying a small amount of starter fluid into the intake and then see if the engine tries to run. If it fires up briefly, replace the pump along with checking the fuel filter.

Another trick I like to use to check for spark is using a one of the pocket pen type of AC voltage testers you can buy at a hardware store. The type that detects AC voltage inductively and doesn’t need to touch a bare contact. It will start flashing within about a foot of a good ignition wire. They sell for around $20 dollars and are handy to have around.


OK, I’ve replaced the coil and it still left me stranded. Previously, I had replaced the manual fuel pump with an electric and it still stalled, so I just went back to the previous manual fuel pump. The fuel filter and gas cap are new, new spark plugs, wires, router, distributer cap. Anybody want to buy an Apache? Any other suggestions are welcomed and appreciated.


So what about the 2 dollar condenser I mentioned earlier?