One hole don't fire??????

460 Ford in my 49 Merc. #4 don't fire, changed the plug and wire, no spark. Can it be as simple as a cracked cap? No noise like a bent or loose pushrod? Thanks......Beet

 

when you say it doesnt fire. does that mean you are getting no spark to only that cylinder or is it physically not igniting?

 

Check the cap
ps had a guy come into a parts store looking for " a new hole " since his pal said he had a dead one... Don't do that

 

Runs and starts rite up, #4 has no spark..........Beet

 

I'd vote cracked cap. Maybe even a single worn distributor cam lobe.

 

Had a 350 Chevy once that wouldnt fire on #3 (i pulled it from a blazer in a wrecking yard).I ran a compression test and that cylinder had 20 lbs of compression versus 120 in the others.I drove it moderatley for a few thousand miles and finally decided to rebuild it.When i pulled the heads i found that the exhaust valve on #3 was cracked all the way to the stem and had a V shape from it folding up from the crack .I would run a compression test and see what #'s you have all around the board and go from there ...

 

Does it have a points or duraspark ignition system?,I had a duraspark distributor not shoot spark to one cylinder and it was in the distributor. I dont know exactly what was wrong as I had another distributor and just put it in.

 

Duraspark.

 

If replacing the cap does not fix it there is a part that I dont know what its callled that is under the rotor that might be the cause,if the pick up coil is not working it would not fire at all so I would suspect that part first.

 

beet what color box is it i might have one color is where the wires go in...jeffrey

 

got to be a bad wire or plug or cap, for no spark

 

if I were looking for "a new hole" I wouldn't be going to the parts store

 

Check for white lines in the underside of the cap. That would indicate a crack.

 

Installed a new cap. Compression 100#+. Still not fireing #4......Beet

 

If it wont spark on just that cylinder but has compression ,you may have a bad or fouled plug.If its not the plug then its gotta be a bad cap ,if its just one not firing ...

 

check that number 4 lead with a multimeter or try another plug lead on that dead cylinder...........

 

I put a new plug on #4 wire and started engine, moved it to ground to see if it was fireing, ZAP, shocked the shit out of me. Maybe check compression again! Thanks all...Beet

 

vacuum leak intake gasket #4

 

well whatn did ya find out burnt valve ? intake leak? jeffrey