Looking for Some advice

[Joel Talka]

Hello Again,

I'm looking for some direction and advice regarding my 1966 Coronet. I had a small block built for it which is in there; a 408 with 10.0 compression. Ignition is MSD with the separate box and I am running an MSD coil as well. Carb is a "Brawler" which looks to be a 4150 knock off of sorts, came with the engine. Car now has power brakes and a vacuum container, Idle vacuum is about 11", taking vacuum off the back of the carb. Total distributor advance (no vacuum advance) is 20 degrees which comes on quickly, basic timing is set at 15 degrees.

I had the car out yesterday here is what I am seeing.

Idle - I can't seem to get a consistent idle.. it's all over the lot.

Start up - No matter where I set the electric choke, there is no smooth idle at start up.. whole engine shakes like crazy until it warms up a bit, like it is missing.

Bucking - Trying to drive it a bit yesterday it started bucking.. give it some gas and it is almost like the ignition is dropping off and on.

My instinct is saying possible coil problem but again I'm not sure...and am looking for some advice.

Thanks,

Joel

 

[Don Frelier]

I'd double check firing order.

Pull the plugs and check them (too rich?)

With it idling as well as possible get some insulated gloves and pull one wire at a time off each plug.
If it doesn't change (drop RPM) their is something wrong with that cylinder.

Compression test

Hopefully not a bad cam...

 

[Jerry Hall]

First, was the engine warmed up before driving? My first thing would be to disable the electric choke and see what I'm dealing with. Improperly working choke can cause many of the problems you talk about.

 

[Joel Talka]

Hopefully today I can do some more digging.. The engine is basically new and was run in by the people who built it. When it was doing what I described it was at operating temperature. The electric choke seems to be operating properly. The ignition wires are from the old 318 which was in the car when I got it 2+ years ago. I have a new set of MSD wires which need to go in there... There is one other symptom which I am remembering now... Warmed up, at idle, it won't readily take gas.. it "breaks up", shakes like crazy...not all the time which is weird... Flakey coils do flakey things so I may also just pop a new cheapie in there to see what happens.... Appreciate the input!!

 

[HALIFAXHOPS]

It can also be the distributor advance coming in really quickly.

 

[1967coronet]

Old fuel ?

 

[Joel Talka]

It can also be the distributor advance coming in really quickly.

Long story.. I had to replace the distributor shipped with the engine because it was damaged in transit. Replaced it with exactly the same one..and replicated the advance springs in the new one. The advance does come on quickly as I am using one light and one medium spring but again this is the same setup the builder had when he ran the unit in.. I do appreciate they advice. A new coil showed up so my next step is to swap out the old one (MSD Blaster - which have lousy reviews for reliability as I have learned) so we shall see.