For the life of me, I can't get my '87 tuned so doesn't ping, backfire, or be really hard to start when hot.
It has a carb and distributor recurved/rebuilt by @FJ40Jim . All the hoses are hooked up correctly per the desmog guide. When everything is set to spec, I get a ping under loads like merging on to the interstate or going over a bridge. It is also very hard to start when hot (the carb fan is working correctly). I can retard the timing a bit to eliminate the ping, but then I get a backfire on coast down. I can add a little more advance and it starts right up, but also pings more. I've tried moving the vacuum advance hose to the secondary pot and that helps a little. The best I can get right now is adding a little more static advance and disconnecting & plugging the vacuum advance altogether.
The engine idles nice and smooth, vacuum at idle is nice and steady, everything works. Get's decent mileage (10-11 mpg). When I pulled the plugs a couple of the core insulators were burned & blistered so I'm not imagining the ping.
I've tried running higher octane but that just seems to move things around a little (ping starts a little later, etc.)
What am I missing?
It has a carb and distributor recurved/rebuilt by @FJ40Jim . All the hoses are hooked up correctly per the desmog guide. When everything is set to spec, I get a ping under loads like merging on to the interstate or going over a bridge. It is also very hard to start when hot (the carb fan is working correctly). I can retard the timing a bit to eliminate the ping, but then I get a backfire on coast down. I can add a little more advance and it starts right up, but also pings more. I've tried moving the vacuum advance hose to the secondary pot and that helps a little. The best I can get right now is adding a little more static advance and disconnecting & plugging the vacuum advance altogether.
The engine idles nice and smooth, vacuum at idle is nice and steady, everything works. Get's decent mileage (10-11 mpg). When I pulled the plugs a couple of the core insulators were burned & blistered so I'm not imagining the ping.
I've tried running higher octane but that just seems to move things around a little (ping starts a little later, etc.)
What am I missing?