rick66

My apologies to the forum for disappearing for a few years. I have been driving my car minimumally - spring/summer. The car is a 66 327 350HP, everything pretty much original. Restored the car in 2009.

Last week I drove the car 5 miles for coffee. Stopped at the convenience for coffee, shut the car off. Upon returning to my work the car coughed and shut down, then restarted and repeated this coughing/shutdown process as I nursed it back to work. Never happened before.

So I do the same thing the next day. And the car shuts down at exactly the same spot, 1 mile from the convenience store .... and I nurse it home. Try it again the third day and the car shuts down again at exactly the same spot. I nurse it home again. Temp in all cases high 70's low 80's.

So I ask around and I get three possibilities: 1) Fuel filter, 2) Coil and 3) Vapor lock. I replace the fuel filter and the coil.

Take for a longer spin and the car is doing great. Then the car shuts down, starts and goes for a bit, shuts down, goes for bit and then no start at all. Remove air cleaner, pump throttle rod and no gas visible. Get towed home for the first time ever. Argh....

My race car friend says it's the ethanol content in the gas the vaporizes easily. The sell ethanol free 91 octane locally - he says to try that. I am reluctant as I have used 93 octane since engine rebuild.

He also suggests the put an electric fuel pump near the tank.

I beseech the experts here at the forum for a suggestions/solution.

Frankie the Fink

First thing to do is check the pin in your fuel pump and make dang sure it isn't "walking out" of the actuator arm...there has been a zany spate of that on here lately. Then, make sure your fuel cap is venting properly. Then examine your fuel filter and perhaps even run some gas from the carb line into a mason jar and examine it for rusty bits, gunk, water, etc.. All of this should take more than 1/2 hour.

At 70*/80* outside ambient air and the car's temp normal vapor lock is a long shot IMO...

There is an outside chance it could be the 'red wire' syndrome. Carefully pop off your bulkhead connectors near the master cylinder and look for signs of corrosion (green stuff) and/or scorching/overheating. HOWEVER - that usually results in a dramatic complete electrical shutdown...

After all of this do try the ethanol-free gas and report back on results...

rick66

Thank you Frankie. I will give it a whirl.

John BX NY

rick
On my 67 350 hp the vapor lock issue was greatly improved when I wired the heat riser in the open position....

Frankie the Fink

There are several ways to deal with it short of the complications of going to an electric fuel pump

R66

I have had three vehicles that had pin holes in the fuel line before the pump that caused symptoms similar to what yours are. The first one, the car ran great after setting over night. A few miles down the road, it began running rough. Finally it would die. No fuel in the carb. New pump and carb, no fix. Finally found a pin hole in the metal line allowing it to suck air. After setting about 30 minutes, the car would re-fire with some long term cranking to fill the carb and run good for a few more miles. Second one was a cracked hose at the tank. Third one was the line rusted almost in two in the protective rubber over the line where it came out of the tank. Only the first one resulted on a visible drip on the floor as the hole was in a low point in the line.
Also agree with bad pump, Trash in the tank, fuel filter plugging, etc. An electric pump is just a crutch, not the cure.

59BlueSilver

I had almost the exact same thing happen to me. Almost never figured it out. Turned out it was rust in the fuel tank. As you were traveling down the road, rust particles would get sucked around the pickup sock in the fuel tank and shut off the fuel supply. Usually happened at the same location every time. Wait a while, they would fall off and you could restart. Then it would happen all over again. New tank, new pickup tube, new filters, no trouble since.

rick66

Well to summarize so far .....

>Replaced filter below fuel tank. Still had the issue.
>Replaced the coil. Still had the issue.
>Checked filter at carb - Clean as a whistle
>Fuel pump actuator shaft still in place.
>Checked sock in tank - Clean as whistle.
>Blew out gas cap vent hole - Haven't driven it yet.

I guess I need to put it on the rack and check the lines. Maybe change out the fuel pump while I am at it.

leif.anderson93

What filter is this?? The only thing below the fuel tank should be a rubber fuel line leading from the tank to the steel fuel line

rick66

I added one from NAPA.

Powershift

This extra filter can cause excessive pressure drop in the fuel pump suction....which could affect the fuel pump operation. I would remove it.

Larry

EDIT: If you feel an additional filter is needed, put it in the fuel pump discharge line to the carb.

R66

You don't necessarily need to replace the fuel pump. If you look at the small hole in the side to make sure it is not leaking fuel with the engine running or at least cranking, the diaphragm is probably good. Remove the pump, check the arm and spring to see that the spring holds the arm all of the way up (no slack in the movement). Look at the pin thru the arm and make sure it is not sticking out on one side and thus coming out.
Redneck tests after removing the pump: Put a hose on the pump inlet to a fuel can and a hose to an empty container. compress the arm by hand to assure it is pumping. A couple of strokes should get a shot of fuel. Or put your finger or a cap over the inlet after you fully compress the arm. It should hold the arm in place until you remove your finger.
Pro test on the car: Remove the line from the tank to the inlet of the pump. Put a hose on the inlet to a can of fuel. Put a fuel pressure gauge on the outlet of the pump. Crank the engine and you should get 5 to 7 psi and the pressure should not leak back rapidly, if at all.
The added fuel filter at the tank kind of tells me you might see rust or something in the tank? I have never seen an old car with a filter in front of the pump from the factory, don't know what it would do to pressure, but I haven't seen everything.
You'll find it, keep plugging.

63 340HP

I find C2 vaporlock is usually overheating of the fuel line from the pump to the carburetor. The proximity of the lower radiation hose to the fuel line being the cause and solution. Separation of the two, and/or insulation being the solution.

I found wrapping the fuel line with electrical wiremold, the split corregated wire mold, to work as well or better that the closed cell foam rubatex or armaflex pipe insulation (and easier to slip in the fuel line).

leif.anderson93

I would remove this filter and replace with a correct ethanol tolerant fuel line. Then go for a drive. Simplest thing to try at this point and, as mentioned, this filter is restricting fuel pressure attempting to get to your fuel pump.

Powershift

Fuel vapor lock is where the gasoline/fuel begins to boil and vaporize in the fuel line causing the pump to cavitate or lose pumping ability. This can be caused by too high a fuel temperature or too low of a system pressure.

Placing a restriction in the fuel pump suction line can reduce the system pressure to the fuel pump and cause this same condition as too high a temperature. When the exhaust pipes get up to full operating temperature it can get a bit hot where the fuel line runs from the tank to the pump.

Larry

Frankie the Fink

I'm still skeptical of vapor lock, but, yes, the OP didn't do himself any favors with that pre-pump filter. And also as noted the pump-to-carb lines I've seen on some cars barely nestle between the hot engine heads and radiator hoses... Some judicious positioning (read that as bending) of the lines can eliminate that... At times I've wrapped that hard line with some rubber hose which helped..

Specs for fuel pressure and fuel volume tests are in the shop manual tests..

rick66

Thanks for all the suggestions guys. I will keep at it until we are back on the road. I will be out of town for a week or so. I will update when I return.

Regarding the below the fuel tank in-line filter: it has been in place for about 12k miles without an issue.

tuxnharley

Does that supply the warp core or a flux capacitor?

426 Hemi

Just for the heck of it you might also want to replace the condenser. Had a couple quit working when heated up----cools down and works again.

63 340HP

Only if you install the rare earth magnets to align the molecular dipole moment and dilate the hydrocarbons to displace the vapor.

I have a special "0" GM part number Winters foundry casting of Greenwood CanAm magnet anode holder, but it's not NCRS approved for Sting Rays (it is only good on C3's that are limited to 88 mph).