2800CS engine cut out

Wobdog

Wobdog

a.k.a Mike
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Here is a baffling puzzle. My 2800CS runs great but every now and then the engine just cuts out and I need to restart it. Seems to happen after I have driven some time and then stopped for a few minutes. Cars stars right up but as I am up shifting it just completely dies. I restarts no problem but is a bit disconcerting. This is completely random and I have no clue what could be causing it

Ideas?
 
Wobdog said:
Seems to happen after I have driven some time and then stopped for a few minutes.
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Given that it happens when the car is fully warmed up, and then has been heat soaking for a few minutes, I would guess vapor lock. I assume you have a carbureted 2800, with its original mechanical fuel pump. Might a fuel filter be partially clogged, making it hard for the pump to pull fuel all the way from the tank?

I used to live in Los Altos! Bought my coupe during my time there. I know it's been cold lately in the Bay Area - did this happen recently? Vapor lock is more likely on a hot day.
 
If it restarts easily I suspect something other than heat soak, that usually requires lots of starter cranking to get going again. I agree with Jay's fuel filter suggestion, I would consider replacing the ignition coil, is it old? These can test fine when cold but fail when hot and rpm's increasing.
 
Cut out meaning cutting out instantaneously or taking a few seconds to cut out?
 
Cut out is instantaneously. One minute running then not. I have only had the car since January, but it did happen on my test drive and the owner said his mechanic could not figure it out. Happens once most times I take it out, but very random. I am going to be more aware of exact circumstances but you have given me good starting points with the fuel filter and the ignition coil
 
Also check all wires attached to the coil. Remove them, sand and clean the male and female spades, tighten the female spades so that they go back on snugly.
 
I had a 320i that would cut out instantly and with no warning. An old timer at a dealer said that the copper winding in the distrubutor can crack and cause this issue even if it looks fine. After searching everywhere else with no luck, I swapped the distributor and the problem went away. I thought he was FOS at first but I should have trusted him from the onset since his name was Helmut!
 
I would get a new Bosch blue coil and get rid of the ballast resistor.

CHeck your points (dwell) if you still have them.
 
The Pertronix works fine if it is setup right. Different versions require different coils and voltage to them. I have been running one for many years on my 2800CS without any problems with the Pertronix.

I have a 69 Fairlane Cobra that had a Pertronix ignition when I bought it 2005. After a year the Pertronix pickup in the distributor fried. After some investigation I found it was one of the original Pertronix pickups which is supposed to use a reduced voltage like points accept at startup. The resistor wire had been bypassed and the Pertronix was getting full voltage all the time. I bought the next generation Pertronix that is recommended to run at full voltage. It has specific resistance required for the coil which is different than stock. I bought a Flame Thrower coil that was designed to work with the next generation Pertronix pickup. That combination has worked very well for over 15 years. I have not had to worry about change in timing due to point wear and I don't have to change points on a regular schedule. Many people like to use points and I have no argument with that.

I agree with electrical issues in the coil area for the OP's problem. I did have issue with the coil in my 2800CS. When approaching redline is would begin to misfire and was progressively getting worse. I changed the coil and the problem went away.

I had a new coil fail on my Austin Healy Sprite race car. It did not have a Pertronix but did have an electronic ignition with Nology capacitance discharge spark plug wires. It initially started to misfire and then would shut off. Once cooled a little it would re-fire. After contacting Nology, I found the combination of the electronic ignition and the capacitance discharge wires would overwork a standard coil causing it to overheat. I bought one of their heavy duty coils and have had no problems with that ignition system for over 25 years.
 
adawil2002 said:
throwing the Pertronix away
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If it is an instantaneous cut out and it restarts and runs immediately as if nothing had happened , it is 99% an ignition fault.

As Andrew says, certain models of Pertronix are susceptible to this sort of failure. I think Pertronix has a fail safe feature to shut off when it encounters a fault condition such as an an abrupt drop out in shaft rotation data . Cycling the power to the Pertronix “reboots” it.

Next time it dies, do not rotate the key back to “off” before trying to restart. Just rotate clockwise to crank it. This is to NOT reboot the Pertronix unit. If it starts right up then it is probably not the Pertronix that is failing

All that said, I would look for a loose connection/wire first because your cutting out happens when you are shifting. When you shift gears, you may be causing the motor to rock on the mounts enough to break a flaky wiring connection.

I have an old car that would do this. resolved by replacing the positive wire & spade connector to the coil (which also powers the decades old and still reliable Pertronix unit).

John
 
Check also that the spark plug "boots" are not cracked at the plug. When I first got my car home, three of the six were broken.
 
I have to also add that the Petronix in my E3 has been going for 10 years without an issue, the one in our 67 mustang for 5 years.
 
bavbob said:
I have to also add that the Petronix in my E3 has been going for 10 years without an issue, the one in our 67 mustang for 5 years.
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I’ve got two that are going on 15 years and one that was a PITA despite being replaced twice (went back to points).
 
Wobdog said:
Cut out is instantaneously. One minute running then not. I have only had the car since January, but it did happen on my test drive and the owner said his mechanic could not figure it out. Happens once most times I take it out, but very random. I am going to be more aware of exact circumstances but you have given me good starting points with the fuel filter and the ignition coil
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With apologies, it is hard to rely upon the prior owner's mechanic's alleged automotive knowledge and detective work. To the extent possible, it might be helpful for you to confirm your vehicle's state of tune/mechanical condition and whether there have been any modifications, e.g., pertronix. Pictures might fill in some parts of the puzzle.

Although my first suspect would be the coil and coil connections (including ballast resistor) a bad or loose condenser could also cause an intermittent stalling condition. If it has not already been performed, consider inspecting the condition of ignition points, rotor, distributor cap, ignition leads, spark plugs and coil connections - all of which is de rigueur in most shop manuals as part of a routine “tuneup.” If you are satisfied that everything is fresh and properly adjusted, consider swapping the coil with a known functioning unit. This. of course, does not guarantee a fix, since it is not impossible for fifty-year-old wiring to loosen or shed some insulation at or near a ground. The same holds true for a coil that might have seen decades of service and exposure to the elements.
 
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