Bill, sometimes........! The frequency valve runs at a fixed cycle when cold, un-plugging it switches it off. Why can't you understand why that'd change the way the engine runs? You keep pointing out out that you know what CIS stands for. Constant Idle System/Speed. And you're now telling us that it's rubbish and that you prefer to throw it away and make do with using the brass screws, which will give you a fixed amount of air at all times, meaning your idle will be slow when cold, fast when hot, and go up and down like a yo-yo as your ac cycles. Your problem was a VERY SIMPLE electrical issue that I'd put money on being one of the pins under the coil cover. The CIS in the DeLorean is elegant, simple and extremely effective, and really easy to trouble shoot if you have a basic understanding of electrics and a wiring diagram. The biggest problems I've ever had fixing the idle control system always stemmed from someone monkeying around with the original system (pins swapped around in the idle speed regulator plug being the most memorable). Also it doesn't always follow that trouble idling is a problem with the idle control system. Make sure you understand the system and that everything else is working correctly first! (this refers to a specific car) Please quit giving "advice" that's actually your own opinion. I really do pity anyone who goes out now and tries to disable their original idle control system based on your say-so. My 2p - I'm happy with a DeLorean that hunts form cold as long as the lambda system is in warm-up. A quirk of the idle control is that it tends to hunt when the mixture is rich... which it will be before the lambda system cuts in (engine warm enough). This moment is very obvious, because a) the frequency valve note suddenly changes and b) the engine instantly goes from hunting to a smooth stable idle. My former #1458 has my stage 1 performance upgrade and without the lambda system, idles as solid as a rock at all times. Martin content22207 wrote: > In theory, frequency valves don't fluctuate until water temp is up. In > practice, they seem to monkey with the lower chambers anyway. Numerous > times I've unplugged the frequency valve on a cold engine and had that > characteristic idle hunt smooth out. Don't know what fails between > theory and practice, but something obviously does. > > Regarding CIS -- you're at the mercy of the idle speed motor & control > module. Mine stuck closed at a stoplight once. Had to ride the > accelerator pedal to crack the throttle plates until I could get home > and throw the stupid thing away. 'Twas then that I figured out what > the balance screws were for and how to set them. > > Why the comment about carburetion? (It's true, but curious since so > very few of us run it). > > Bill Robertson > #5939 > > Recent Activity > > * > 4 > New Members > <http://groups.yahoo.com/group/dmcnews/members;_ylc=X3oDMTJmcWJrOWVrBF9TAzk3MzU5NzE0BGdycElkAzExNTQzMjAEZ3Jwc3BJZAMxNzA1MTI2MjE1BHNlYwN2dGwEc2xrA3ZtYnJzBHN0aW1lAzExOTc4NjEwOTU-> > > Visit Your Group > <http://groups.yahoo.com/group/dmcnews;_ylc=X3oDMTJlZTY4dDdxBF9TAzk3MzU5NzE0BGdycElkAzExNTQzMjAEZ3Jwc3BJZAMxNzA1MTI2MjE1BHNlYwN2dGwEc2xrA3ZnaHAEc3RpbWUDMTE5Nzg2MTA5NQ--> > > Y! Sports for TV > > Access it for free > <http://us.ard.yahoo.com/SIG=12j7e78sa/M=493064.10729671.11699924.9977693/D=groups/S=1705126215:NC/Y=YAHOO/EXP=1197868295/A=4767085/R=0/SIG=127pn01k0/*http://us.rd.yahoo.com/evt=49021/*http://digitalhome.yahoo.com/sports> > > Get Fantasy Sports > > stats on your TV. > > Yahoo! News > > Kevin Sites > <http://us.ard.yahoo.com/SIG=12jv85dad/M=493064.10729659.12153716.8674578/D=groups/S=1705126215:NC/Y=YAHOO/EXP=1197868295/A=3848607/R=0/SIG=10q7s9jm5/*http://hotzone.yahoo.com> > > Get coverage of > > world crises. > > Biz Resources > > Y! Small Business > <http://us.ard.yahoo.com/SIG=12j1m1art/M=493064.10729657.11333348.8674578/D=groups/S=1705126215:NC/Y=YAHOO/EXP=1197868295/A=4025321/R=0/SIG=12a352npd/*http://us.rd.yahoo.com/evt=44092/*http://smallbusiness.yahoo.com/r-index> > > Articles, tools, > > forms, and more. > > . > > [Non-text portions of this message have been removed] To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/dmcnews/join (Yahoo! ID required) <*> To change settings via email: mailto:dmcnews-digest@xxxxxxxxxxxxxxx mailto:dmcnews-fullfeatured@xxxxxxxxxxxxxxx <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/