danny41972

Brett240, you were right it was the jets in the carbs. I bought a set of carbs on ebay. rebuilt them, put them on and it runs great. Thank you for your help.

About 2 years ago I took these carbs apart cleaned them up put em back together. I did not change the needles. But I did change the setting of the needles. When I took them apart the shoulder of the needle was even with the bottom of the piston. When I put them back together I put the shoulder of the needle even with the groove in the bottom of the piston. I heard somewhere that this was the correct way to set them. Is that the correct way to set them? Brett, it sounds like you nailed this problem down, I hope, because I tried just about every other thing I could think of. Where can I get new jets? Do I need to replace needles too? If so where do I get new needles?

OK. here is a problem that has me baffled and really upset. First let me tell you my engine configuration. I put a 280ZX engine with flat top pistons in my 240z. I put the E88 head on top of that engine. I also put a mild performance cam on that head. SU carbs. I know that this will yeild a high compression ratio but I thought it would be acceptable. This engine was running great for about 2 weeks I was having fun and then all of a sudden while I was accelerating the engine became very weak. If I step on the gas hard it backfires. When I accelerate the exhaust sounds funny it kinda sounds like a rattle out of the exhaust(not muffler rattling against frame). Now when this car is not in gear it runs and sounds normal and I can easily rev it up. But when I try to drive it, it is just very very sluggish. Timing is correct. Replaced fuel filters. Spark plugs and wires. Compression is good. I tried a different mechanical fuel pump.No change. I dont have an electric fuel pump. I had a crane ignition on and I changed it back to the old points and condenser ignition. Same problem. Any ideas would be appreciated.