[NateB68]

I had another mechanic look at it at the garage I work at. He said it was a misfire. It's a '68 with a 302, Edelbrock intake and carb, new plugs last year, wires, rebuilt stock distributor, good cylinder compression, timing is set to factory specs. I don't know where to look now. The engine shakes, and it pops and skips in the exhaust. I run 87 octane in the engine. Any ideas?

Much appreciated,

Nate B

 

[CougarCJ]

Try using the 351W firing order.

 

[67.5xr7]

Think I would start with the condenser/points, then coil connections. Any tapping noise?
A small amount of crud in carb passages can make an engine run rough.
Sounds like fuel delivery or unburnt fuel.

 

[1970fastcat]

Could be fouled plugs too. If the fuel doesn't ignite in the cylinder, then it will ignite in the exhaust when it make contact with hot exhaust. Just because they are new doesn't mean they aren't fouled. If the carb isn't tuned right it can foul them pretty quick.

 

[Jeff Manger]

Could be in ignition, carb or combination thereof, worse case bad valve/lifter/spring, as spoke of make sure you have firing order correct, is the engine old? might be time to check compresion etc. fyi petronix makes some neat stuff to replace points in stock distributor.

 

[Bad69cat]

Identify what year the engine is if you don't know....that will maybe help assuming no mods have been done...octane has nothing to do with anything other than engine ping/knock when it's under load. You have to get it running good first before you worry about that.....try al the simple stuff first, then move into the deeper things. Check for vac leaks with a can of carb spray, check all the wires for condition/fit, check that they are in correct place and firing order, check you vac lines for rot

 

[NateB68]

The engine is a '73 302, the car sat in storage for 18 years, so I think the vacuum lines could be it, I've only changed a few, but it look like a bowl of spaghetti when you start trying to trace them.

 

[NateB68]

Ran very rough with the Windsor firing order, thanks for the tip though!

 

[Bad69cat]

You can cap them all off until you prove out the motor itself too....maybe easier to narrow it down