rich280zxt Posted March 9, 2008 Share Posted March 9, 2008 Hey guys, I bought a set of triple webers 40 DCOE for my L28 240z. I started two days ago with a perfectly running set of Hitachi carbs, unbolted them and installed the webers. They were used and the person I bought them from couldn't tell me the last time they were ran, but they looked super clean. All the gaskets appear new. Yesterday I was able to get the car running, but I had to modify the pedal, throttle linkage was too long, so I wasn't able to drive it until today. Well after I fixed the pedal I tried starting it, and it turns over but won't stay running. I'm 95% sure its a fuel issue. I know I'm getting fuel but what would cause it not to run the very next day? I sprayed starter fluid into the air horns to try and help it run but as soon as the fluid burned off it would stall on me. I adjusted the rich-lean settings all the way down and then off 2.5 turns and the sync three turns. Also, yesterday when the car was running the whole motor shook really bad, had alot of vibrations, what would cause that? Even the muffler vibrated horribly. What should I check? Could the floats not set high enough cause it to do this? Quote Link to comment Share on other sites More sharing options...
twistex Posted March 9, 2008 Share Posted March 9, 2008 As Far as the engine shaking badly is probably due to the fact the carb's are not synced properly.I would also not turn out those adjustment screws 2.5 that is to much. From what I have read and noticed on my own is that if you have to turn them more then 2 turns to get an idle its to lean of a idle jet. If you only have like 1 turn out to idle its to rich. I would try turning them out 1.5. Back out all the throttle plates out and start over just opening each one a little bit and make sure when you press gas pedal they all open at same time and evenly. You should be able to play with it while someone is starting it to get it to idle. I use a air flow sync tool that lets me sync them pretty good. Also I would pop the covers off and check the floats. One time I to got a clean set of side drafts and my engine wouldn't run correctly. I took the tops off to notice that one of the carb's float was installed upside down! If you know your getting fuel into the carb's, I would also clean out all the jets and such. Good Luck. Quote Link to comment Share on other sites More sharing options...
rich280zxt Posted March 9, 2008 Author Share Posted March 9, 2008 When I got the carbs, I pulled the covers off and cleaned the insides, the floats, needs vlaves and everything. I'm thinking its the height of the floats needs to be adjusted. Where can I get an air flow sync tool locally, any idea? Thanks Quote Link to comment Share on other sites More sharing options...
SHO-Z Posted March 9, 2008 Share Posted March 9, 2008 When I got my SK Racing, weber clones, who ever ran them last did not drain them. All of the jets were plugged and bowls were full of hard jelled gas residue. It took days to get them cleaned out. I used a tip cleaner for a welding troche to clean the jets. Even if the bowls are clean your jets could be plugged. I would pull all of the jets and clean them. Quote Link to comment Share on other sites More sharing options...
rich280zxt Posted March 9, 2008 Author Share Posted March 9, 2008 okay, I'm pulling the manifold and doing a thorough cleaning today. Thanks for the help, I'll let you know what happens. Quote Link to comment Share on other sites More sharing options...
rich280zxt Posted March 10, 2008 Author Share Posted March 10, 2008 I cleaned all the jets today, and found out that one of the float needle valves was sticking so I took all that apart and cleaned it. The car idles around 2500 rpm. One of the Sync screws is missing, could that be the cause to idling so high? I adjusted the mixture screws somewhat to try and get the idle to come down but that didn't help. However, I was able to drive the car, so that made my night. When I was driving it, it ran okay unless I pushed the pedal too far, then it felt like it was running on 4 cylinders. Is there anything else I should look at? Other than it idling too high and not getting full throttle response it sounded amazing. I was extremely satisfied with the acceleration, seems to be twice as fast. All the vibrations are gone. Its funny because when I'm not driving it the exhaust sounds like its perfectly tuned. It doesn't smell like its running rich. How many turns (about) should the idle screws be turned? Quote Link to comment Share on other sites More sharing options...
rich280zxt Posted March 10, 2008 Author Share Posted March 10, 2008 Anyone live close to Jacksonville, or near enough to come help me tune these carbs? I can't figure out why it won't run on all six cylinders consistently. I've got money and lots of time, I just can't figure it out. Quote Link to comment Share on other sites More sharing options...
evtech Posted March 10, 2008 Share Posted March 10, 2008 Hi Mate You'll fight forever to get the optimum from this type of carb, all you realistically can do at home is set the linkages to open them evenly, (tip: pull the filters and confirm the butterfly is fully open at full throttle) balance them, and set the idle, you need access to jets and a rolling road to sort out the fueling issues once you get it rolling. The only one thought is have you checked the choke tube (aux venturi)diameters (should be stamped on them) as if these aren't a matched trio of carbs then these tubes could vary in size, usually in say a 40dcoe you'd find a 38mm choke tube. I've found this link that may help you http://www.teglerizer.com/dcoe/dcoe45_tour.htm Regards Nigel Quote Link to comment Share on other sites More sharing options...
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