[66 tempest]

first, I want to say I had this posted on another forum, it's not a pontiac..
but I really could use some help.. it's a 385 stroker with the setup I have on it, I have never had any issues with the motor.. Even with out a choke, it would start at the first crank, and run flawless.. I have an msd adjustable timing control, msd disrtibuter, without vacume advance, since 1990... THE beginning of the season I noticed the engine getting a bit slower to start, and running a bit rough during warm up, as time went on, the car would start to run on... as time went on it got worse. end of summer I noticed the car on the hiway started to feel like it was possibly mssing a cylinder.. now it's to the point where it just sounds like crap.. I took a video of the ignition spark, I got about a 1 inch or more arc, but the acr was pure white, no blue.. all the plugs were replaced, cap, and wires resistance were checked. and they are fine. I start the car like I always do, advance four degrees let it run for 20-30 seconds then return to normal settings. I have gear drives, I dont recall my ignition timing settings, but they have not been touched, the car has loads of bottem end tq, couldn't be happier with the timing..

INTIAL STARTUP


WARMUP


CLOSEUP

[66 tempest]

I should add, that my vacume gauge dropped from 12-14 to 10-12.
I noticed that when you click the clip it says servy over loaded, you may have to click the clip several times to get connected..

[engineer]

coil or cap will give poor spark color. loss of vacuum means a leak or change in timing maybe a chain slip.

[ModifiedPONPON]

What year is the motor?