Engine won't start when it's Hot.

Coils do not like heat. Try locating the coils off the engine in a cool place with air flow. Also check the points for binding on their pivot posts at 200 degs and while your at it check the point resistance with an ohm meter. You may have to increase the spring tension on the points and lube the pivot posts. I have experienced both of these conditions. Fun@@#$^&.
 
Yes, the coils are mounted on the Engine. Up front, but up high. Checked them with a laser heat gun when it's running and they registered 170. Will check the points. Thanks for the suggestions.
 
I'm not sure if I can help any but this a harman collins set up, right? Correct me if I am wrong, but isn't this two separate 4 cylinder ignition systems? If you had said it only runs on 4 cylinders, I could believe that one of the sides of the ignition system has failed. As it does not fire at all, we need to be looking at something that is common across both ignitions.

Are you 100% sure it is a non start due to no spark? Or could it be a typical over rich problem, or vapour lock? I'm familiar with over rich situation in 94s but have never ran a stromberg. I have not experienced vapour lock.

Next time the non start situation arises, connect one of the plug leads (or one from each side of the ignition) to a spare spark plug and see if it sparks.

I'm wracking my brains trying to think what the problem might be, but other than the above, I can't think of anything.

Mart.
 
Newly rebuilt engine, lots of fresh paint. Condensors mounted on a nicely painted bracket.

It is possible that you have a poor ground that fails when hot. The condensors need a good ground. Both being faulty? Failing at the same time? Not likely. But a common ground failing ... maybe. I'd be checking that bracket, assuming you have one, for good grounds.

(I know that on a stock distributor with a loose mounting bolt that grounds the condensor can make you scratch your head.)
 
Last edited:
Do make sure the bracket for the condensers is held tightly to the vacuum brake adjustment nut. Bubba sometimes leaves the nut loose for you to adjust the brake. Also the vacuum brake adjustment assembly to the distributor body should be tight. Are you using the 40 Ford ignition switch? H&C want both coils to be fed from two separate wires back to the ignition switch. They wanted 12AWG for 6V coils (at least) I would suggest #14 for 12V. Make sure the ignition switch is fed from #12 wire back to the circuit breaker and all the connection points are tight.
 
There is one common problem when going to 12 volts, you must bypass the resister under dash. With 2 coils feeding from 40 ign switch, maybe better going to key start.
Could it be you are wired to a circuit braker
If you had a alligator clip put the coils direct to battery.
 
"Bubba sometimes leaves the nut loose for you to adjust the brake."

Poor Bubba. The cost of fame.
 
Mart said:
I'm not sure if I can help any but this a harman collins set up, right? Correct me if I am wrong, but isn't this two separate 4 cylinder ignition systems? If you had said it only runs on 4 cylinders, I could believe that one of the sides of the ignition system has failed. As it does not fire at all, we need to be looking at something that is common across both ignitions.

Are you 100% sure it is a non start due to no spark? Or could it be a typical over rich problem, or vapour lock? I'm familiar with over rich situation in 94s but have never ran a stromberg. I have not experienced vapour lock.

Next time the non start situation arises, connect one of the plug leads (or one from each side of the ignition) to a spare spark plug and see if it sparks.

I'm wracking my brains trying to think what the problem might be, but other than the above, I can't think of anything.

Mart.
Click to expand...
You are right about the "Harman & Collins" ignition system. It is two separate systems by design, and it will run on four, but not now.

Yes, the no start mode is no spark. Haven't ruled out the vapor lock possibility, but right now, we are looking for fire at the plug. Using a spark plug tester in line and it indicates no fire.

Appreciate your input.
 
If it were me I'd replace the HC setup with a regular distributor and try it, if it fires up when hot then you have isolated the problem to the HC unit, if it doesn't fire then look at the coil and the wire from the coil to the distributor.


Just my $0.02 worth.
 
You have a good point.! I have been guilty of too much paint in the wrong places, and I will certainly look into this. Unique to the "Harman & Collins" system they do have their own bracket for the two condensers.

Appreciate your input.!
 
D. Jones said:
If it were me I'd replace the HC setup with a regular distributor and try it, if it fires up when hot then you have isolated the problem to the HC unit, if it doesn't fire then look at the coil and the wire from the coil to the distributor.


Just my $0.02 worth.
Click to expand...

I think this is a good idea. Several times, I have been able to finally find a pesky problem by swapping in a known good unit. As a matter of fact, I'm in the middle of just such an exercise right now concerning (O/T) Quadrajet carburetors.
 
Terry said:
Do make sure the bracket for the condensers is held tightly to the vacuum brake adjustment nut. Bubba sometimes leaves the nut loose for you to adjust the brake. Also the vacuum brake adjustment assembly to the distributor body should be tight. Are you using the 40 Ford ignition switch? H&C want both coils to be fed from two separate wires back to the ignition switch. They wanted 12AWG for 6V coils (at least) I would suggest #14 for 12V. Make sure the ignition switch is fed from #12 wire back to the circuit breaker and all the connection points are tight.
Click to expand...

This is good info, I will be looking for a loose nut.
 
D. Jones said:
If it were me I'd replace the HC setup with a regular distributor and try it, if it fires up when hot then you have isolated the problem to the HC unit, if it doesn't fire then look at the coil and the wire from the coil to the distributor.


Just my $0.02 worth.
Click to expand...

Appreciate your $.02 worth. Check my reply on post #18.
 
tubman said:
I think this is a good idea. Several times, I have been able to finally find a pesky problem by swapping in a known good unit. As a matter of fact, I'm in the middle of just such an exercise right now concerning (O/T) Quadrajet carburetors.
Click to expand...

Us do it yourself's are guilty of parts swapping, and I am one of them,but at this point I am trying to retain this ignition and isolate the problem,instead of replacing it. I have a fresh stock distributor on stand by, if all else fails.
 
The first thing you have to do in a case like this is define the problem as precisely as you can. That's what swapping the distributor is about. There have been mentions of vapor lock, ignition switch wiring, and I don't know what else, so it sounds like no one is really sure where the problem actually is. I don't think anyone was suggesting permanently replacing the H&C, but you have to find out if it is the problem or not.
 
Agree. Swap as a diagnostic step, not total abandonment of the HC unit. If the fault persists it is not the HC unit, if it goes away it is.

Mart
 
You measured coil temp at 170 degrees - motor at 200 degs at same time? Have you cleaned the contacts in the ign switch? When the motor is at 200 degs check the continuity of the primary and secondary of both coils. I think 170 deg coil temp is very hot to the touch! Engine runs fine until it rises to 200 digs I am assuming and if so the problem is heat related. If those coils were mine, I would find a cooler place for them.
 
Steve, the way you have both coils fed from one wire, if either coil shorts when it gets hot it would likely disable the other one due to there being a large voltage drop. You might try removing the wiring feeding power to the coils (leave the distributor side of the coils connected) and then feed both coils directly from the battery with individual leads. If one of the coils fails, you should continue to run on four cylinders. since the good coil would still have power directly from the battery.
 
tubman said:
The first thing you have to do in a case like this is define the problem as precisely as you can. That's what swapping the distributor is about. There have been mentions of vapor lock, ignition switch wiring, and I don't know what else, so it sounds like no one is really sure where the problem actually is. I don't think anyone was suggesting permanently replacing the H&C, but you have to find out if it is the problem or not.
Click to expand...

Appreciate your suggestion, and I have definitely considered this. My crew chief has also suggested this, and I agree that this would be a way to isolate the problem. Just wanted to clarify that doing away with the H&C distributor is not an option at this time. I have swapped this before, and am willing to do it again.
 
You must log in or register to reply here.
Back
Top