I'm having a serious issue getting the new moter in my 93 vert running right. I cant seem to run it for any length of time before it turns the plugs pitch black. The motor is a brand new 306 (specs here)
Heres what Ive done......sorry but this will get long.
Originally fired the motor with a holley 750 vac/sec that I had previously removed from one of my other cars. I know its a little much for this motor but I cant afford a new one right now. Car fired and I locked in the timing at 12 with the vac line off, hooked the vac advance back up and set the float levels in the carb. The motor sounded great, nice racy idle (has a B303) and real responsive when I snapped the throttle. Hooked up the vacuum guage to dial in the idle mixture. The screws didnt seem to make as much difference as Im used to and I could tell the car was idling pig rich because it would make your eyes water standing behind it. I got as best I could and moved on to topping the tranny fluid, antifreeze, PS fluit etc. The more the car ran the more it started missing every so often an finally got to the point where it finally would die if I let it idle for about 30 seconds. Pulled a plug and found it to be totally black. This is after a total run time of probably 20 minutes.
I installed a new set of autolite 25's gapped at 50 and fired it up so I could finish getting the tranny fluid full so I could get the car down off the ramps and fiddle with the carb some more. The car started kind of hard this time kind of acted like it was flooded. Before it killed the first plugs I could reach in the window, hit the key and it would fire right up. I dropped it down and backed it down my driveway and drove it back up to test out my shift linkage. It only ran about 5 to 10 minutes before it started to not want to stay running again. Pulled a plug...black as can be.
I figured the carb had to be the problem but rather than fixing it since I knew it was too big, I rebuilt the carter 625 that I originally bought for this car. Installed the carb and another new set of autolite 25's. Gapped em at 47 this time. Not sure why, just started thinking maybe I had em too wide. The car started kind of hard again this time and didnt sound nearly as good as it did the very first time I fired it. I played with the mixture screws and got the idle fairly smooth but I had to turn the mixture screws way out and I had to keep the idle kind of high. It never sounded right. Kind of really drony if that makes any sense, not a nice crisp idle like it should. Couldnt hear the cam at all. If I leaned it out some you could start to hear it but not very well and then it would start missing and would die if I put it into gear. If I snapped the trrottle, it was real responsive and sounded nice and smooth when it was reved up but just wouldnt idle right. After about another 30 minutes of playing with the carb and timing, plugs are toast again.
This is getting a bit expensive. 3 sets of plugs and the car hasnt left my driveway yet. I'm at the end of my rope and I really need help determining why its eating plugs.
Heres what Ive done......sorry but this will get long.
Originally fired the motor with a holley 750 vac/sec that I had previously removed from one of my other cars. I know its a little much for this motor but I cant afford a new one right now. Car fired and I locked in the timing at 12 with the vac line off, hooked the vac advance back up and set the float levels in the carb. The motor sounded great, nice racy idle (has a B303) and real responsive when I snapped the throttle. Hooked up the vacuum guage to dial in the idle mixture. The screws didnt seem to make as much difference as Im used to and I could tell the car was idling pig rich because it would make your eyes water standing behind it. I got as best I could and moved on to topping the tranny fluid, antifreeze, PS fluit etc. The more the car ran the more it started missing every so often an finally got to the point where it finally would die if I let it idle for about 30 seconds. Pulled a plug and found it to be totally black. This is after a total run time of probably 20 minutes.
I installed a new set of autolite 25's gapped at 50 and fired it up so I could finish getting the tranny fluid full so I could get the car down off the ramps and fiddle with the carb some more. The car started kind of hard this time kind of acted like it was flooded. Before it killed the first plugs I could reach in the window, hit the key and it would fire right up. I dropped it down and backed it down my driveway and drove it back up to test out my shift linkage. It only ran about 5 to 10 minutes before it started to not want to stay running again. Pulled a plug...black as can be.
I figured the carb had to be the problem but rather than fixing it since I knew it was too big, I rebuilt the carter 625 that I originally bought for this car. Installed the carb and another new set of autolite 25's. Gapped em at 47 this time. Not sure why, just started thinking maybe I had em too wide. The car started kind of hard again this time and didnt sound nearly as good as it did the very first time I fired it. I played with the mixture screws and got the idle fairly smooth but I had to turn the mixture screws way out and I had to keep the idle kind of high. It never sounded right. Kind of really drony if that makes any sense, not a nice crisp idle like it should. Couldnt hear the cam at all. If I leaned it out some you could start to hear it but not very well and then it would start missing and would die if I put it into gear. If I snapped the trrottle, it was real responsive and sounded nice and smooth when it was reved up but just wouldnt idle right. After about another 30 minutes of playing with the carb and timing, plugs are toast again.
This is getting a bit expensive. 3 sets of plugs and the car hasnt left my driveway yet. I'm at the end of my rope and I really need help determining why its eating plugs.
