JMD

Coil???

When the car is not running,,, do you have a strong spark????

Mach1972

How can you test the spark with the engine not running? Or, maybe I don't understand.

andrewmp6

hes asking when it acts up is the spark normal or less id give it a tune up maybe rebuild the carb

Mach1972

It doesn't really "act up". It either runs great or dies, no in between.

Hornblower

It sounds like the engine is being starved for fuel. Somewhere in your fuel delivery system you have a problem. Either you have a blockage, or your fuel pump is about to go out on you.

JMD

You need to narrow your problem down to a system, The hit or miss thing is not working.

Start with the basics of pre-computer diagnosis,

Ignition
Fuel
Timing

Check these out in a systematic manner. See if you have spark, pull a wire off of a plug, hold it close to a metalic object and have someone roll the engine over, if you have a good strongsparkwhen the engine is not "running" (wont run), then you can eliminate the ignition.

Again, when the car wont run, look down the carburator, and open the throttle a few times, if the carb is pumping fuel into the carburator (accelerator pump) then the carb is getting fuel to it, you have eliminated the fuel pump and linesas the problem. Even if the carburator is still suspect, the car should at least fire if the accelerator pump is dumping gas into the manifold. (do not try to start the car while looking into the carb)

Put a timing light on the car, if the timing is on, this can be eliminated.

By doing this, you can at least narrow your search down to a single system, either fuel or ignition.

It seems as if everyone is pointing you in the fuel direction, they may be right, and they may be wrong...... pretend like you are doing an internet search,,,, narrow your results, or, just keep changing parts helter skelter and fixing things that aint broke.

Also, if the car is running, and suddenly dies, without stuttering and such, I would say that it is not a fuel issue,,,,, if you are still in the changing parts mode, change the coil, they are cheap enough.

Mach1972

Thanks JMD. Let me add that there is never an opportunity to check the spark the way you describe because the the engine will start right up every time after it dies (stalls).

JMD

If the car starts right away each time, then it may not be the coil, I was under the impression that it did not always start up right away, but I would still go through the procedure as described in my previous post.

If the car does start right away, the problem will be harder to diagnose. Also you might want to check for vacuum leaks as well.

Mach1972

We think we have narrowed the problem down to the tach and coil.
When the car is running, the volt meter shows 11 - 12 volts at the coil. Compared to a buddies car at8 volts. According to the wiring diagram the (stock) tach is supposed to bring the voltage down to around 5 - 7 volts with some sort of resistancewhile engine is running. It does not appear to be doing this. Could the coil be "heating up" and causing the intermittent stalling/bucking? We're really scratching our heads, what do you guys think? Thanks, again.

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fastbackford351

I had a problem very similar to that when I first got my fastback.

It turned out that the accelerator linkage was pushing back against an ignition wire just enough to cause it to disconnect momentarily. It would start right back up, but under acceleration it would die again.

I finally found the splice and replaced the whole wire, end to end. No splices. No problem.