Mandic 0 Posted March 20, 2007 Hi, I'm interested in how do people control idle on TBs, the way I see it most (I dont know if this is common thing or not) people leave throttles slightly open, so when engine is hot it is able to run on normal revs. But cold starts might be a problem with such setup. Now, can idle on TBs be controlled by ICV? Do Jenveys have input on each cylinder in order to run ICV or is this not a common practice? Cheers Ziga Share this post Link to post Share on other sites
Sandy 191 Posted March 20, 2007 It is possible to arrange an idle valve with most ECU's, but it's a fair bit of hassle and by cunning ignition advance temperature compensation you can make it so it'll hold a slightly fast idle during warm up after about 30 seconds initial running. Share this post Link to post Share on other sites
Mandic 0 Posted March 20, 2007 Well lets put it this way, I'm doing custom TBs for my turbo engine and need to know how much difference really is there. I have limited experience with TBs so need to know a few basic things such as at which temperature (5°C?, 0°C?) things become problematical, considering having TBs on turbo engine is ICV desirable or not, and if I bother integrating it into my design, is it worth the hassle, or it will make little difference and not worth bothering. Cheers Ziga Share this post Link to post Share on other sites
M3Evo 0 Posted March 22, 2007 Hey Ziga, just got your PM Stu's engine is indeed alive and the car's road legal as of last weekend! Anyway, idle control. I've left it to the ignition advance and having the throttles slightly open to take care of the idle. On mine, it'll idle at about 400rpm until the engine's warmed up a little bit when it'll have made it's way up to about 800rpm. On Stu's it seems to be happy to idle at around 900rpm from cold, but mine used to do that until the engine had run in a bit for some bizarre reason so I reckon his will drop on cold idle after a while. For the set of throttles I'm working on at the moment, I've incorporated a rail which links all cylinders so that a decent vacuum for the servo can be taken off, and an IACV can be incorporated. Personally think that having an IACV is a good idea and will make the car more pleasant to live with every day, rather than having to keep the revs up for a few minutes once started. Share this post Link to post Share on other sites
Mandic 0 Posted March 22, 2007 Yes, I'm also thinking this way, I'm plan to integrate vacuum rail with take off for servo and Map sensor and also ICV rail, I just wanted to be sure extra work will make a difference. Have You mapped the engine yet? If so, what is the power and how is the trottle response? Thanks! Ziga Share this post Link to post Share on other sites
Super Josh 4 Posted March 22, 2007 Jenvey sell a manifold so that you can link an IACV to the 4 TBs, just for this purpose. If you want to make the engine behave like a factory system then I think it is necessary to have both ignition advance and IACV control for idle. Josh Share this post Link to post Share on other sites
Dream Weaver 2 Posted March 22, 2007 I just have a stop screw which keeps the throttles open slightly, but when its cold its very difficult to start and I have to hold the revs at 3k rpm for about 5-10 seconds, during which time I get pops from the inlet. Once its warm its fine and idles around 1100 which is OK for now, though when the engine bay gets very hot it must affect the throttle stop as the idle then drops. I thought about using an ICV and plumbing it in via the bike body vacuum holes underneath. Share this post Link to post Share on other sites
M3Evo 0 Posted March 22, 2007 Yes, I'm also thinking this way, I'm plan to integrate vacuum rail with take off for servo and Map sensor and also ICV rail, I just wanted to be sure extra work will make a difference. Have You mapped the engine yet? If so, what is the power and how is the trottle response? Thanks! Ziga We've been out an mapped it so that it's drivable up to full throttle and about 5000rpm, but have no idea what the power would be at the moment. I've not had a go yet either so couldn't tell you what the throttle response is like Share this post Link to post Share on other sites
Mandic 0 Posted March 23, 2007 Cheers guys, will work some more on the design and post the pics when done, Josh, do You happen to have some pics, or maybe know the hole diameter, need to know how much is enough for idle. Thanks Ziga Share this post Link to post Share on other sites
28CRAIG 2 Posted March 23, 2007 There is drawing's and information on the jenvey web site in the accessories section for the air bypass valve. Share this post Link to post Share on other sites
Mandic 0 Posted March 23, 2007 Ah yes, silly me... thanks Cheers Ziga Share this post Link to post Share on other sites
