Miles Posted December 14, 2001 Share Posted December 14, 2001 I have a 74 350 sbc with a holly 4bl carb in a 72 240z. Engine looses power around 1500-2000 RPM and backfires through the exhaust. I have replaced all ignition electrical: points, plugs, wires, cap, rotor,and condensor. I set the dwell at 31 and the timing is set at 8 deg btdc. I tweaked the mixture screws and got some minor improvement e.g., when I stomped on it in 2ed gear it took off like a rocket, but then crapped out at about 2500 RPM. The carb is very old and I am thinking of replacing it. Any suggestions on getting the car tuned smoothly and for a replacement carb. Also, When I let off the gas at any speed the engine backfires through the exhaust. Thanks Quote Link to comment Share on other sites More sharing options...
Tim240z Posted December 14, 2001 Share Posted December 14, 2001 Sounds like the carb is running way too lean on the primaries. Rebuild or replace?! Tim Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted December 16, 2001 Share Posted December 16, 2001 Is the choke falling shut? Take the choke assembly off and try it again. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.