Hi Steve! This accel 2020 kit requires the use of the stock resistor or one of their coils with the builtin resistor.Very emphatic about that warning the unit could destruck without it.I do have a dwell meter and I will try and get it to read off this unit.Any other thoughts.It does seem to act like a misfire at idle as you described.With good vacuum reading the motor is in good shape mechanically you think?

  

Well, thats a good vacuum reading 19, so at least you,ve ruled that out, i,ll stand by and see how you do with the accel. best regards bill.

  AussieBill            YYYY    Forever Y Block     YYYY

 Down Under, Australia

I have used a timing light on each plug wire to see if that plug is firing at all or intermitently.

You gotta have the right tools and know how to use 'em.

TC - Austin, Texas

Thanks Tom! Thats a good suggestion.Timing light along with the dwell meter I will do a couple of checks.

  

You might try disconnecting the vacuum line to the distributor and plugging it temporarily on the carb side.  If the idle smoothes out, you have too much ignition timing at idle which could simply be a result of using a direct vacuum source for the distributor versus ported vacuum.

Lorena, Texas (South of Waco)

Mark,in the last year or so I've had a similar problem with 3 of my Fords.A 94 Explorer, a 94 F-150 and my 56 Fairlane.They all developed a miss at idle,but ran fine at speed.The plugs and wires were all  fairly new.Believe it or not,the problem with all 3 was one bad plug.These were the same Autolites that I've been using for years but Autolite must have made a batch of defective plugs and I was lucky enough to get at least three of them.In each case the plugs only had about 3,000 miles on them.They looked fine,but replacing the plug in the missing cylinder cleared up the miss.So,if you're using Autolites,maybe that's an area to look at. 

 

Paul,

Boonville,MO

I'm seeing a lot of the same characteristics with my 272. It starts so good, runs so good, but when it gets up to operating temp (190) the idle is horrible. I usually put it in neutral at the stop lights. Acceleration is great when I leave the lights, it's just the idling at temp thats bad and I hate to mess with it cuzz its so sweet the rest of the time. All the plugs look great, pertronix with flamethrower, plugs at .040, holley 465. I put a phenolic spacer under the carb, the carb is always cool, the fuel lines are cool, possibly the pump could be hot but with the acceleration like it is, it seems alright. Vacuum is 17 and steady, just acts up when its up to temp and idling. Gary

       

Gary, 55 Vicky, St. Germain, Wisconsin

 

Paul! How did you figure out which plug it was?I have a suspicion that it is an ignition problem-plug or wire maybe.I have changed the advance hookup from ported to direct and backed the timing timing down a bit.No difference.So I am still looking although I will be using a timing light as suggested on each cylinder and see what happens.Off idle its great so this is really starting to annoy!Sounds like Gary and I are in a similar situation.Thanks

  

Sounds like you,re getting closer to fix? loosen all the plug lead ends on the plugs, makes it easier to remove with hot running engine, get car idling with miss and  remove one plug lead at a time, noting any change in idle characteristics, the cyl that doesnt change much is usually the problem one. best regards bill.

  AussieBill            YYYY    Forever Y Block     YYYY

 Down Under, Australia

Mark,as AussieBill suggests,with it idling pull one plug wire at a time until the culprit shows up.These plugs always looked perfect when removed from the engine,but for some reason they would not fire at low RPMs.I replaced the bad ones with the same kind and number and have never had another problem.

 

Paul,

Boonville,MO