36 Pickup stalling when warm

[david.skinner]

I suspect I'm about to open Pandora's box but I would like some guidance in the process to fault-find my wife's 36 pickup car engine ('38 24 stud Engine to the best of my knowledge with a Crab distributor) stalling when warm.

We've had the car a few months and it has run perfectly. I'm in the very final stages of overhauling the cooling system and the car will not start and idle when warm.

Interestingly one thing I have noticed that when turning it over it will either fire on the first rotation of the crank of not fire at all. Once it has stalled I also seem to bet getting some crankshaft locking when subsequently turning it over where the engine abruptly stops turning with some associated unpleasant loud noises. It has also backfired on me a couple of times with subsequent cranking which is really scary.

It seems to start well when cold with say four pumps of the throttle and full choke but when it warms up and I gradually close the choke I can hear it starting to miss and it then stalls and wont restart.

First thoughts are obviously fuel or electrics but can someone point me at a 'standard' proceed for fault finding this sort of thing or is the range of possible causes so wide that its a case of testing everything?

Thanks in advance
David

[Scott H in Wheaton]

Why are you choking a warm engine?

[Lawson Cox]

Read his post again. Chokes it when cold, starts up but when it gets warm it backfires and quits and won't start. Sounds like either a bad coil or condenser. Condenser is cheap. Replace that and see what happens. Then replace coil if it is still giving trouble. IH200 is a good condenser to use to replace old one. (I believe it is IH200). If it still won't run right, pull the coil and distributor and send it to Skip in Florida and let him rebuild units for you. Good insurance even if the rebuild doesn't help. Replace only one thing at a time. Keep us posted. Oh, does it back fire through carburetor, or tail pipe?

[david.skinner]

Yep thanks Lawson - I wasn't clear. Only choke on a cold start but wont start warm. It backfires through the carb - never seen that before - bit scary for me
D.

[dean333]

Backfiring thru the carb can be and electrical issue as suggested. I lost the ground in the distributor of my 57 Studebaker, backfired and caught fire.

[flatjack9]

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If it quits when taking the choke off, it would indicate the mix is too lean. Sounds like a carburetor problem for one thing. Don't understand the crank locking bit.

[Scott H in Wheaton]

Originally Posted by david.skinner

but when it warms up and I gradually close the choke

This the part I read. On a warm engine you OPEN the choke. Maybe he meant when he pushes in the knob

[flatjack9]

Yup I took it to mean that as he opened the choke it wouldn't run. Too lean.

[36Bill]

The abrupt stopping and locking up sounds like a stray short perhaps in the wiring or cap so that it fires on the wrong cylinder. That would also cause the backfire too.

[Rascal]

Pull the dizzy right out , Replace the points & condenser & check for Any visable sign [black powdery residue] shortage between earth wires & or insulated wires, & it all sounds like a classic ignition short out to me.

[Phil Gillespie]

There is a guy on here Ian in Napier who has the machine to check and set up your distributor. Could be worth contacting him or Flathead Ted in Auckland.
Phil NZ