brad.arcova
Member
Done all the tests and adjustments I know how to do and am stuck.
In the driveway, when slowly increasing throttle to, say 2000 rpm, the engine will hold for a moment and then gradually die, need to add more and more throttle to keep it going. At some point it catches again, revs a lot so I let off the throttle an then repeat the process. Can't seem to hold a steady 2000 rpm with constant throttle. Is this normal? Frankly, because of all the salt on the roads, the car's not going to get a road test until we have some rain to wash it off. Should I just wait until the roads are clear, do a road test and see what I've got under load?
Engine is a new 383 crate engine with a 234/244 cam, air gap manifold, MSD ignition, with 6A ignition box, Holley 670 cfm street avenger. Most people seem to use a bigger carb with that engine, a 750.
Initially, I had several symptoms that the car was running lean, white plugs (but rich at idle), surge at cruise, stacatto exhaust, (like a missfiring cylinder.) Timing was at 14, primary jets were stock 65, transition slot was uncovered about 1/4" at idle, vacuum at idle is ~13", power valve is stock 6.5. Plugs indicated the timing was slightly advanced. Float levels dead on.
Since then, I've rebuilt the carb and checked everything, including blowing out all the passages really good. gone up 4 jet sizes to 69, set the timing to 12, cracked open the secondaries at idle so that I've got about only a .04" square of transition slot showing. I've reset the idle mixture and still have control of it with the mixture screws even with the secondaries cracked open. It still stinks really bad as if it's idleing really rich. Float levels still dead on. Doesnt' seem to be any point in checking the plugs again until I've driven it a few miles.
What should I check next?
Brad
In the driveway, when slowly increasing throttle to, say 2000 rpm, the engine will hold for a moment and then gradually die, need to add more and more throttle to keep it going. At some point it catches again, revs a lot so I let off the throttle an then repeat the process. Can't seem to hold a steady 2000 rpm with constant throttle. Is this normal? Frankly, because of all the salt on the roads, the car's not going to get a road test until we have some rain to wash it off. Should I just wait until the roads are clear, do a road test and see what I've got under load?
Engine is a new 383 crate engine with a 234/244 cam, air gap manifold, MSD ignition, with 6A ignition box, Holley 670 cfm street avenger. Most people seem to use a bigger carb with that engine, a 750.
Initially, I had several symptoms that the car was running lean, white plugs (but rich at idle), surge at cruise, stacatto exhaust, (like a missfiring cylinder.) Timing was at 14, primary jets were stock 65, transition slot was uncovered about 1/4" at idle, vacuum at idle is ~13", power valve is stock 6.5. Plugs indicated the timing was slightly advanced. Float levels dead on.
Since then, I've rebuilt the carb and checked everything, including blowing out all the passages really good. gone up 4 jet sizes to 69, set the timing to 12, cracked open the secondaries at idle so that I've got about only a .04" square of transition slot showing. I've reset the idle mixture and still have control of it with the mixture screws even with the secondaries cracked open. It still stinks really bad as if it's idleing really rich. Float levels still dead on. Doesnt' seem to be any point in checking the plugs again until I've driven it a few miles.
What should I check next?
Brad
