76 Spider engine won't restart after warm

[bmdfiat76]

Hi all. We are newbies here to the forum. We have a 76 Spider that doesn't want to restart after the engine is warm. It turns over fine when it's cold, and will start, but after it's warm, it turns over slowly and will not start until after the engine has cooled down. Appreciate any input.

[So Cal Mark]

turning over and starting are two different things. If the engine is cranking slowly, you may have a bad starter or voltage drop

[bmdfiat76]

Thank you Mark. We were wondering if the problem could be with the timing.

[bmdfiat76]

Also wondering what the amp output of the alternator.

[bradartigue]

Thank you Mark. We were wondering if the problem could be with the timing.

If it runs fine when cold, or whenever, then it isn't the timing.

If it is cranking slowly when hot then you probably have a weak starter, but I'd have to hear it or run a meter over it. If it is cranking fine and not starting hot (after it has been running just fine) then I would replace the fuel pump as the diaphragm is likely shot. They do this when the pump is ancient.

[majicwrench]

Having the timing too far advanced can cause it to crank hard when hot. Simple to find out, when it is cranking slowly hot, simply unhook coil wire and try again. Obviously it won't start like that, but if it cranks faster you now have a good clue.
Keith

[So Cal Mark]

don't waste any money replacing a fuel pump. The carb will have fuel in the bowl and will run for a few minutes on that even if the pump has failed. You'd have other issues if the pump was bad. If the motor cranks normally when cold but slowly when hot, more than likely the starter motor is worn out. It's best to test voltage at the starter to confirm the problem before swapping parts. Unless you have deep pockets

[bradartigue]

don't waste any money replacing a fuel pump. The carb will have fuel in the bowl and will run for a few minutes on that even if the pump has failed. You'd have other issues if the pump was bad. If the motor cranks normally when cold but slowly when hot, more than likely the starter motor is worn out. It's best to test voltage at the starter to confirm the problem before swapping parts. Unless you have deep pockets

I do agree that the problem needs to be diagnosed first. Turning slow or turning fine and not starting are different things.

I do not agree on the fuel pump diagnostic, the behavior I describe is precisely what happens to a weak pump when hot, and bowl does not remain full. Doesn't matter though if the problem is the starter dragging or something else.