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Danno

Well-known member
Joined
Feb 5, 2013
Messages
610
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3
Location
Mount Prospect Illinios
My Car
1972 Fastback, Sportsroof
Did a total ignition system tune up a month or so ago, everything but the distributor and coil, all parts were from ROCKAUTO.

The car ran great after the parts installed so took it out on the tollway and blew the snot out of it, no problems. A week later it was idling in the driveway and it died. Trying to restart, it sounded like it was totally out of time. It would start, but pop and fart and die.

Troubleshooting done: Fuel pump ok, fuel filter clear, spark from coil good, spark from plugs good, coil resistance good, swapped a to a good known coil and the old condenser for s**ts and grins, no help.

Finally reinstalled old points and  removed top of carb and sucked the old gas out of the bowl and refilled with my lawn mower gas, and it fired right up. Put everything back together and restarted numerous times and it fired up immediately each time and idled for a while. 

Up to this point I had not driven it, just idled it, so I figured I'd take t out to get my confidence back. I got a block from home and it died and restarts were like before, popping and farting. I limped back home and put some octane booster in the tank ( 3/4 full) and tried a restart, same problem. I still have the old points in there and plan on Echlin points as my next dart. Ideas???

It ran great before and now this !!!!!!!!!!!!!

 
The car ran great after the parts installed so took it out on the tollway and blew the snot out of it, no problems. A week later it was idling in the driveway and it died. Trying to restart, it sounded like it was totally out of time. It would start, but pop and fart and die.
Have you checked the timing?

 
Did you replace the condenser in the distributor? Do you have an old one you can swap in? They can break down when they get hot.

A good spark from the coil or at the plugs doesn't mean a lot, just that you're getting a spark when there is no pressure on the spark plugs. It takes considerably more energy to fire a spark plug when it is under compression pressure in the engine than when sitting in free air.

Make sure the inside of the distributor cap is clean and dry, no carbon traces or cracks. Make sure the spring tab on the rotor is making good contact with the center terminal in the cap.

Is the ground wire that connects the breaker plate to the distributor body in place and secured?

Is the pivot point on the breaker plate in good condition? If the bushing is worn it can cause similar problems because the points won't maintain gap.

 
Last edited by a moderator:
When it doesn't start, you need to find out whether you have spark and gas.  Put a timing light on #1 spark plug wire and see if the light blinks on/off.  Pull the air cleaner off, and see if you can see gas when you move the accelerator rod.  If both check out, then the problem is related to timing (although it is strange that timing would be on, then off, then back on again).

 
Everything is new: points, plugs condenser, wires, cap and rotor, accelerator pump works, filter is clear, gas flow good out of the fuel line, and it still won't start after it sits a while. 

Last week I put a set of $20 Echlin (sp?) points because I was using my old points at the time for troubleshooting. For the record, it ran good temporarily with the old points during troubleshooting too whenever it decided to cooperate.

After I installed and adjusted the new points, I started it immediately and it ran great for about 2-3 minutes, then died, like it was running out of gas. I was able to get it restarted and quickly started revving the motor at the carb manually when it would start to die. I had to do this several times until it idled ok on it's own. I would then rev it at high rpms and let it settle back down to idle, and "rinse and repeat" several times. It idled that day for about a half hour with no problems, even after shutting it off and restarting it. Fast forward to just now, where I just went out and tried starting it and the same thing, popping and farting and no start. I probably flooded it trying to start it this time, 

I plan on bypassing the tank tomorrow and running good gas from a line directly into the pump, although I'm getting a feeling it's a  problem somewhere in the carb. I have been looking at a new motor craft 2100 anyway because that's what I have in there now. I'm pretty sure it's a fuel problem, either bad fuel (doubtful, because it does run good when it finally starts), or something in the carb that, after the car sits a while, decides to not function.........IDEAS???????

 
I encountered a 2-barrel carburetor in a Fairmont that had idling problems. Turned out to be a porosity in the casting that drained into the intake manifold. It was bad enough that it added about a quart to the oil pan. At first I thought it was a fuel pump problem, took a while to chase it down, took the carburetor off, set it on the bench, filled the bowl with gas and it all ran out in a few minutes.

This was a few years newer when quality control problems were running rampant, I never encountered this before or since.

 
Since you have tried almost everything, I'llthrow out a long shot. Could the + and - wires on the coil be reversed? Chuck

 
It sounds like a fuel problem. While unrelated, I had an RV that did a very similar thing; it would pop and spit at startup because the mixture was so lean; it had a sticking float needle that was somewhat random. I figured it out my putting fuel through the air horn and it would run great for a while and then the same thing would happen.

 
I'll check that, but being as it does run normally I'm not sure that's a problem. At this point I'm ready to try anything short of throwing in the towel and taking it to my local "guy" who is honest and does all the heavy work on our cars.

 
You may be experiencing fuel percolation in the bowls. Does it do this cold, as well as after it's warmed up? If it's only when it's warmed up, that would be where I'd start. It's pretty easy to diagnose, the boosters will tend to drip fuel with the engine off, and there is typically a bunch of vapor. If you don't have at least a 1/4" thick carb base gasket, get one. 

Seriously doubt the slipped timing chain theory, once they go, they're gone. 

Because it is so intermittent, I'm also leaning toward electrical issues, specifically bad grounds. I had similar issues many moons ago and it was an MIA chassis ground. Use a multimeter from the distributor body to the battery (-) terminal, it should read under 10 ohms. If not, verify your battery to fender apron to block ground path is clean and solid. Clean the ground wire in the distributor, clean and reseat the breaker plate screws. Clean the distributor base and clamp/hardware. 

 
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