Mikey Posted November 9, 2008 Share Posted November 9, 2008 So here is the problem im having. l28 with the dual DGV's. Off idle or a low rpm (2k>*) when i get on the throttle it hesitates. I hear the carbs drawing in air but it just stutters and in about a half second it picks up again. if i give it full throttle it bogs, i can hear it drone and make the deep growl but takes time to pick up. Any ideas on what this could be? Any input is greatly appreciated. -Mikey Quote Link to comment Share on other sites More sharing options...
zuperair Posted November 9, 2008 Share Posted November 9, 2008 Was the car running fine with the duals up until these symptoms occurred? Or did you just set this car up to run the downdrafts? Quote Link to comment Share on other sites More sharing options...
Mikey Posted November 9, 2008 Author Share Posted November 9, 2008 when i got the car it already had the downdrafts.but it ran terrible. i started playing with the carbs and dropped in a new fuel filter, they were clogged with rust. it ran pretty good. i balanced the carbs and it ran pretty good but was way too rich. a guy i know that has a 240z with an identical setup to mine told me to replace the accel pumps. so i just got some new ones in and it fixed the fuel mixture issue. now this is my only issue. the last hoop i need to jump though lol. thanks Quote Link to comment Share on other sites More sharing options...
SHO-Z Posted November 9, 2008 Share Posted November 9, 2008 I have the same problem. Have never found a solution to it. I took the carbs apart and checked the transition jets and they were clean. Next time I take them apart will try blowing out the passages. In some ways I think part of mine might be weak spark. My 260 will not pass emissions at idle, high HC. Quote Link to comment Share on other sites More sharing options...
zuperair Posted November 9, 2008 Share Posted November 9, 2008 I still have my old set of DGV's which I ran for about 15 years. They were mostly trouble free, although I did need to rebuild them about every 4 or 5 years...so this would most likely help with the old set you have. Short of that, if I had to guess (not working with it obviously) I would start by making sure I had no vacuum leaks period. These days I have a vacuum tester so if you have one use it, otherwise its back to the old fashioned way. Still pretty simple stuff. Next, I would make sure that your carbs at set at baseline adjustment. 1 1/2 turns out on the idle screw, and 2 on the speed screw. Other than that, I found this article which pretty much is all about your problem and could really help. http://www.theautoist.com/weber_carb.htm Here's a much more detailed progression to tune the carb http://wiki.datsun1200.com/index.php/Weber_DGV_Tuning an exploded view of the carb and it's parts http://s2.pegasusautoracing.com/2008/049.pdf That's where I would start. Vacuum....if this is right, then it helps to isolate the issue to the carb, and not it's installation. From there Baseline adjustments...from there and with the help of the info in the links, you should be able to figure out what the cause is and correct it. Hope this helps... z Quote Link to comment Share on other sites More sharing options...
Mikey Posted November 9, 2008 Author Share Posted November 9, 2008 wow thanks, thats a ton of info. I knew about the first link, thats why i put in new accel pumps. I talked to a local racer that raced 210's in the 80's and he said sounded like the accel pumps were leaking. I know ive got NO vac leaks cuz ive got new gaskets and 4 vac lines. dist, pcv, vac gauge and brake booster Il try and tune them in today, ive got a sync tool. Quote Link to comment Share on other sites More sharing options...
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