Duraspark/HEI conversion

[Anonymous]

Fellas, I recently had my 200 six rebuilt, installed Duraspark dist. w/ Hei module, Mallory (1040?) coil, brand new Weber DGES 38, Clifford carb adapter. The engine starts and runs fine, but has a random miss at idle and lower RPM, runs good at higher RPM. According to Weber tuning instructions I need to install bigger jets as the carb is too lean. I used the stock ignition wire that went to original coil, it reads 12volts w/ ign. switch on. When the car is running I only get 9.5 volts at the coil. Is this correct? I thought this setup required 12v at the coil when running. Not sure what to do next. Thanks for any suggestions.

Mike

 

[falcon fanatic]

Do you still have the pink resistor wire under the dash? I tossed that and replaced it with a new wire that plugs into the same bullet connector but now powers my ignition system with full voltage, which should read 14.4 when the engine is running.

 

[Stubby]

It sounds like a lean misfire. Make sure you don't have any vacume leaks. Then try choking it a little to see if that helps. If it helps try richening it up a little.

 

[Anonymous]

Thanks, Falcon Fanatic and Stubby. I'm thinking it's the pink wire low voltage issue. Had a mechanic friend suggest the lean idle missfire, so I tried to richen it up but did not fix the missfire.

 

[Stubby]

Run a hot wire from the battery to the coil and it should let you see if the low voltage is the problem. If that doesn't work, use an inductive timing light on one plugwire at a time and sometimes you can see whitch cylinder is misfireing!

 

[Anonymous]

Did as Stubby suggested but still no change.I bypassed the pink wire and achieved 14.4 volts at the coil w/ engine running, but I still have a random miss. The miss is not just at idle like I had said before.Adjusted the WEBER 38 dges per instructions which indicates that I need larger jets, but when I pulled the plugs they were black and sooty indicating a rich condition. Only #3 show any hint of being hot enough. Plugs are AUTOLITE 45 w/.035 gap. Also have not been able to find any vacuum leaks.

Thanks
Mike

 

[Stubby]

Open the gap to .045.

Did you try the timing light trick to maybe isolate the problem? Watch the strobe and listen to the miss and you can see it skip if it is a problem with a certain cylinder.

Have you looked at it in the dark? Sometimes you can see sparks going somewhere they shouldn't.

Are all of the post on the reluctor ring ok?

These are the things I would concentrate on. The black plugs can be a result of poor idle mixture from the log intake while the engine is cold.

 

[Alabama65stang]

Try taking off the breather and looking down the carb with it running. Is there gas dripping from the main jets? Mine had the same symptoms. I had the idle speed screw so far open that it was pulling fuel through the main jets and missing and running rich at idle. I had to open up the secondary idle speed screw a little and close the primary back down to where it was just pulling gas through the idle circuit. This smoothed out my idle and also allowed me to adjust the idle mixture correctly as per the Weber instructions.