'64 Sedan - Misfire / Engine Bog / Power Loss / Backfire

[advCo]

We restored the car a few years ago now. The car starts right up and runs great - for a while. Then it will start bucking and bogging down like its misfiring or not getting enough fuel. Sometimes you can give it the gas and it will straighten itself out, sometimes it just keeps on happening for the rest of the ride.

Its sporadic. I've had it out a few times with no problems, and I've had this exact problem occur a handful of times. The first time it died and we had to have it towed. Since then I've been able to make it back to the house.

It has been converted to 12v. Has a new coil, distributor/wires and just about everything else except for the fuel pump. We're thinking the pump may not be working at 100%, but if thats the case wouldn't the problem be consistent and not sporadic?

Any help greatly appreciated. Here's a couple pics of the car.

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"He pulled the mirrors off his Cadillac ‘cause he doesn’t like it looking like he looks back"
'68/'70 Ghia Coupe Project
'70 Westy Project - Champagne I Wannabe
A bunch of vintage Japanese motorcycles
"Much ingenuity with a little money is vastly more profitable and amusing than much money without ingenuity." -A. Bennett

[mukluk]

If it's a fuel delivery problem, you should be able to verify that theory by shutting off the car when the issue is happening and pulling the carb top to see if the fuel level in the float bowl is low. Common causes for poor fuel delivery include a defective pump, restriction in the fuel line, fuel tank outlet partially blocked, fuel tank not venting properly, or the fuel pump push rod binding in the spacer block as it heats up.
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1960 Ragtop w/Semaphores "Inga"

[glutamodo]

I'd be checking the accelerator pump action first. It should be spraying right away whenever the throttle arm is opened.

By the way, that looks like a PICT-1 carburetor... and it definitely is an SVDA distributor. That is a mis-match. The distributor will act primarily the same as an "009" unit, and what vacuum advance you might get will come in at the worst time, at high engine RPMs.
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Andy T.


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[smokey503]

I had a similar issue. On mine it turned out that the fuel line from the tank to the tunnel had cracked.
The fuel pump was pulling air and not pulling enough fuel.
Once I replaced it. It was fixed.
Nice looking car by the way.
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If a car travels the speed of light, would the headlights work?

[advCo]

I will check to verify fuel level in the bowl the next time I am with the car. I verified carburetor and jets were clean and re-cleaned. The accelerator pump is working as it should.

I removed the fuel pump to ensure that pushrod was moving freely, and it was while engine was cold. I discovered that the plastic intermediate flange is broken off in the block, so will be replacing that.

The fuel pump is the only thing that remains "untouched" since we restored the car, do you guys recommend rebuilding the pump with the kits available?

We ran a new main fuel line through the tunnel. Will have to confirm that the lines are clear.

@glutamodo - I just did some quick reading about the SVDA distributor. I was mostly involved with the aesthetics on this project while my dad handled the mechanical. Could the vacuum advance be causing this issue?
_________________
"He pulled the mirrors off his Cadillac ‘cause he doesn’t like it looking like he looks back"
'68/'70 Ghia Coupe Project
'70 Westy Project - Champagne I Wannabe
A bunch of vintage Japanese motorcycles
"Much ingenuity with a little money is vastly more profitable and amusing than much money without ingenuity." -A. Bennett

[tasb]

More than likely the mismatched carburetor/distributor are contributing to the problem but not the main cause. You also need to install a steel shepherds crook between the distributor and carburetor. The steel line rises above the carburetor vacuum port preventing fuel and fumes from deteriorating the diaphragm in the vacuum canister.
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Roads Scholar &
1957 Kombi low mileage 36 hp governor equipped M 178 Slow Drag Winner 2014, 2015, 2018

1965 hardtop Deluxe Microbus owned since 1990 M 620 factory 12 v 1500cc

1961 (October)Single Cab- Road Trip Workhorse

[wfernandot]

I am running into a similar problem. Mine is a 6v beetle sedan. Initially the car got very poor performance (max speed 35 mph). To improve it, I put a new fuel pump and a new coil and Pertronix distributor. My problem got fixed instantly (60 mph). But after two weeks, one day going up a long soft hill it started chugging and eventually stopped. I let it rest few minutes and restarted again without problems. now more frequently it does the same thing specially if drive fast (50 mph). If I Drive slowly and very gently does nor seem to have much of an issue, but if a I sprint and run a bit after 500 yards will chug again. Then if turn off the engine and restart, it comes again normal and idles normal starts and sprints normal one or two times and then start chugging again like the reservoir inside the carburetor empties. I have rebuilt he carb and washed the jets twice in an ultrasonic bath. I am running out of ideas. By the way I rebuilt the car last year and I put a new gas tank.

[wimkever]