Hey guys,
My bros 83 S.P. engine has a miss when running. I think i have tried everything including coils, wires, plugs, dist, vac leak and carb issues but it still has a miss. Kinda sounds like its running on one rotor, maybe one rotor well and not so good on the other Im not sure. I would greatly appreciate any suggestions and help.

Thanks everyone!

 

Have you verified that you have spark to both leading and trailing plugs? Also have you run a compression test?

Also is the miss under hard throttle or under steady throttle?

 

yeah it has fire to both sets of plugs through a couple of msd blaster coils, it only has what looks like a weak yellowish spark though. The miss is at idle all the way through any rpm. It all happened when he was coming home one day with his foot in it and then he said it sounded like it was running on one rotor. I asked him to check the cap and the rotor was burnt up. After replacing the cap and rotor it had the common it wont start problem (cranks but wont start). It sat for about a month and here we are. It runs and drives just not as good as it used to.

We havent checked compression yet though

 

Definitely check compression.

 

One can of Seafoam + 1/8 tank of gas, then go for a drive. The apex seals may have some crud in them which will cause low compression and sometimes the issues you described. Even if this does not correct your specific problem, it will be good for the motor. Good luck.

Also, I don't like the sound of the spark you are getting. Not sure what the cause would be though, off the top of my head. Maybe check the timing, and make sure that all of the new plug wires are routed correctly. Could also be due to bad engine grounding, so maybe clean up the battery cables (at both ends) and maybe consider replacing them.