Jz260 Posted February 28, 2012 Posted February 28, 2012 Hey guys, I just picked up my 260z today, running on SU's. I knew it needed a carby tune up as it runs rich and is difficult to start once it has been warmed up. I took it down to a local workshop and got some advice, the guy had a bit of a play with it and said there is a vacuum leak on one of the shafts. I'm not sure what he did exactly and i'm sure he didn't mean for it to happen but it has now started to backfire through the carbies when you give it some throttle. Has anyone got some advice? And could anyone recommend a good tuning place on the north side of Brisbane for the job? Thanks! Quote
pauly_adams Posted February 28, 2012 Posted February 28, 2012 try disconnecting your vac breather line off the carbies, mine was doing something similar it was drawing vapor into the carbs it was running rich as and backfiring and stalling once removed it was sweet as sugar Quote
dat2kman Posted February 28, 2012 Posted February 28, 2012 Try Jim Milliner at Smart Automotive, in Stone st Stafford, old school guy, he may be able to help. It sounds like the plain bearings that the throttle shaft on one, or both, carbs has worn a bit, allowing air in past the seals, the fashpots wont work correctly and then the jet needles will alter fuel delivery. Backfiring could also be imbalance issue. The only guy that used to look after these, Ian Stewart up central coast way, retired some years ago, he could reco these very nicely Quote
Jz260 Posted February 28, 2012 Author Posted February 28, 2012 Yeah that sounds about right to me. Do you know if Smart Automotive has a dyno? Quote
dat2kman Posted February 28, 2012 Posted February 28, 2012 Yeah that sounds about right to me. Do you know if Smart Automotive has a dyno? He has access to a dyno in Geebung, but your car will have to go to him at Stafford first. Dyno is not cheap, as you are not altering jets, or other settings, there is no need to run it up. Jim will have O2 sensors up exhaust to get it close but i doubt he will need them, once carbs are re kitted, it is a matter of setting idle mixtures, then balance, setting idle speed, that part is easy, it is the re kitting them, that is fiddly. He will know where to get kits, oh, and do both of them! Quote
Jz260 Posted February 28, 2012 Author Posted February 28, 2012 I heard that Stafford tune, just around the corner has a dyno. Heard anything about them? Quote
dat2kman Posted February 28, 2012 Posted February 28, 2012 Staffordtune/paul masterton/mr Motec, just sells motecs now, his dyno is dismantled, in pieces, i was looking to buy it, but it needs to be setup as a commercial venture, noise and suitable premises are the problem. I was thinking of building a dyno cell at my joint, all up cost approx $30 k, gotta do a lotta pulls to pay for itself! Just google Smart Automotive, get it touch, go from there. Unless you are going super shiny multi carbs multi tb injection aftermarket ecu, you do not need to worry about dyno settings. Hitacki SU's are easy to get running correct, ensure ignition is in vgc, carbs have no wear issues, maybe fit a later 280zx electronic dizzy, goid leads, fresh plugs, she'll be fine! Quote
Jz260 Posted February 28, 2012 Author Posted February 28, 2012 So you reckon don't bother with a dyno run at this stage? Just get it tuned based on the o2 sensor readings and so on? It already has electronic ignition and the leads look pretty good, havn't had a check of the plugs though. I'll get onto all that tomorrow. Thanks heaps mate! Quote
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