72DartSwingerV8
Well-Known Member
Hi there,
I've got a 1972 318
.030 overbore
1.88 intake valves
eddy Performer
2.5 exhaust
Holley 650cfm Spreadbore
904 tranny
3.55 gears
The runs smooth at about 1000rpm. But once I put it in gear the idle drops and it starts shuddering every so often in a random way. It isn't a consistent misfire but enough to not drive it around, it makes a slight knock. I think it's pre-detonation. However if I rev it up to 1500 it will backfire out the exhaust. The spark plugs all smelled a little like gas so I think the carb is dumping too much fuel. How do I adjust it to run leaner, or is it another problem altogether?
My understanding now is that I set the timing first by hooking up a vacuum gauge to get the highest amount of vacuum at idle then set it there. From there I don't know what to do on the carbureator end. Same thing? but adjust the idle air mixture screw?
Thanks for any help.
I've got a 1972 318
.030 overbore
1.88 intake valves
eddy Performer
2.5 exhaust
Holley 650cfm Spreadbore
904 tranny
3.55 gears
The runs smooth at about 1000rpm. But once I put it in gear the idle drops and it starts shuddering every so often in a random way. It isn't a consistent misfire but enough to not drive it around, it makes a slight knock. I think it's pre-detonation. However if I rev it up to 1500 it will backfire out the exhaust. The spark plugs all smelled a little like gas so I think the carb is dumping too much fuel. How do I adjust it to run leaner, or is it another problem altogether?
My understanding now is that I set the timing first by hooking up a vacuum gauge to get the highest amount of vacuum at idle then set it there. From there I don't know what to do on the carbureator end. Same thing? but adjust the idle air mixture screw?
Thanks for any help.
