Guest zfan Posted March 7, 2001 Share Posted March 7, 2001 Got a question for the carb experts! I have a 750 vacuum secondaries, problem is the secondaries do not seem to be opening. The carb is manual choke, and when gunned it doesnt open up. Reason I got to looking is the car was acting way under powered! Gutless I guess. The carb is six months old but has seen very little use as it, like many others here is under the knife rather than on the street. Anyway,any idea's or hints would be appreciated. Mike Quote Link to comment Share on other sites More sharing options...
Guest kc6wfs Posted March 7, 2001 Share Posted March 7, 2001 Hi Mike, I just had the same prob with my 750 vac sec. I put in the short yellow spring and a new diaphram. If you go this route get the plastic (unscrewable) top for the diaphram. I had a pinhole in mine and it does not take much to loose vacume there. Also be sure the 4 screws are tight and the diaphram is not kinked anywhere. Dave ------------------ www.geocities.com/kc6wfs/240z.html www.NitroPhotos.com Quote Link to comment Share on other sites More sharing options...
Guest Frank280z Posted March 7, 2001 Share Posted March 7, 2001 Could I get the part number for the diaphram? Thanks Frank ------------------ Build it. Drive it. Improve it. http://www.angelfire.com/extreme2/frankzpage/ Quote Link to comment Share on other sites More sharing options...
Guest kc6wfs Posted March 7, 2001 Share Posted March 7, 2001 Hi Frank, It's Holley part number 135-4. It's about $10.00 i think. Dave ------------------ www.geocities.com/kc6wfs/240z.html www.NitroPhotos.com Quote Link to comment Share on other sites More sharing options...
Guest harth Posted March 7, 2001 Share Posted March 7, 2001 Are we talking Edelbrock or Holley here?? Michael 280ZZ4 Quote Link to comment Share on other sites More sharing options...
Guest kc6wfs Posted March 7, 2001 Share Posted March 7, 2001 Oops.. Gosh I need to read better. hehe. I was thinking holley. sorry guys. Just noticed the topic.. Sorry. Dave ------------------ www.geocities.com/kc6wfs/240z.html www.NitroPhotos.com Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted March 8, 2001 Share Posted March 8, 2001 zfan, Edelbrock carbs have mechanical secondaries. If the linkage hasn't been disconnected they have to open. Make sure the butterfly at the top of the secondaries is moving freely. My Edelbrock carb came with a tuning manual. If you don't have this I sugest getting it. It has detailed info on how this carb works & how to tune it & how to trouble shoot it. Glenn P.S. Its seems gutless compaired too? My Holley double pumper I replaced with the Edelbrock did run better at W.O.T. & had better response. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted March 11, 2001 Share Posted March 11, 2001 The Edelbrock is a mechanical secondary that is vacuum assisted. What this means is the secondary will crack open mechanically, but the vacuum of the engine needs to get high enough to pull the counter weights to the open position. Hope this helps, Troy Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted March 11, 2001 Share Posted March 11, 2001 Sorry with well tuned secondary circuit you shouldn't actually feel them open. This is straight from Edelbrock and Holley respectively. Quote Link to comment Share on other sites More sharing options...
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