Ignition Problem

[Rob_M]

Hey guys,

I am having issues with my car in reference to a bad ignition miss. This spring I installed a MSD ignition and rebuilt my carb – Holley. It ran well for a while but it starting fouling plugs and having a ‘miss’ at part throttle around 3200 rpm. When I gave it full throttle, the miss seemed to disappear. At this time my plugs starting to foul. I figured the carb was out of adjustment so I played with it and tried different heat ranges for the plugs. That helped but I still had this on and off again ignition miss. This Monday I was driving the car and as I approached a stop light I noticed the car started to severely miss. I accelerated to see if I clear it out, (I thought the plugs were starting to foul) but it did not get any better. At the same time I noticed my voltage meter was pegged to the right, above 18 volts! I drove it home with the headlights on which kept the voltage down below 15v. I replaced the voltage regulator hoping that might have caused the ignition issue but it didn’t help. The voltage was correct though… [img]<<GRAEMLIN_URL>>/smile.gif[/img]

I pulled the plugs from one bank and they were semi-fouled and gas soaked. Last week, after a 30-40 mile highway drive, I pulled the plugs and they looked perfect….

I’m wondering if it could be a mechanical issue, burnt valve, broken spring, etc. but wouldn’t the cylinder that had the broken valve be the only one that shows the problem? All four of the plugs that I pulled from the left back were gas soaked and fouled. I find it hard to believe that the new MSD ignition would be causing this issue.

I have checked the plug wires, they are MSD brand, and they looked good. Timing is 36 BTDC at 3200rpm.

I’m going to replace the plugs and check all the plug wires again. I will also pull the distributor cap at the outside chance there could be a crack….

Any ideas would be appreciated.

Thanks

Rob

[Charley Lillard]

Just a thought..Double check your MSD wiring. I was fighting a issue on a Nascar where it would idle just fine but up to speed under load it would miss, foul plugs etc. After much changing crap etc I come to find out whoever restored the car wired both MSD boxes backwards. There are two wires going from the MSD box to the dist. One had a pink stripe coming from the MSD box ..If you match it up with the pinkish purple wire coming from the dist you have it wired backwards. This will run but under load it pulls 30 degrees timing out of the dist. Read the instructions. If you wire it the common sense way it will be wrong. I have met alot of people that had the same issue. Hopefully that is your problem.

[Chevy454]

Good thinking, Clill...a backwards wired coil will run [but like crap] also.