stoner 0 Posted October 17, 2003 OK, this is wierd one. Having read a fews posts, I suspect the ISV, but does anyone else have other ideas? A few weeks ago, I had a couple of instances where my 16v C would start but wouldn't idle. Once the engine got warm it would pick up and the idle would be OK. Now, however, I seem to have the opposite problem! When I started the car this morning, it idled at nearly 2500rpm. The revs don't drop when I pull the clutch in to change gear. If I coast down to a junction in a high gear to drop the revs, when I stop and pull in the clutch, the revs go back up again to 2500rpm! Any suggestions?? Quote Share this post Link to post Share on other sites
GazzaG60 0 Posted October 17, 2003 check your idle switch and for a vac leak. The idle switch is on the throttle body and should click when its engaged. check the throttle cable make sure it aint too tight or stretched. Check for a leak around the ISV. problems with it are hard to find. you can clean out the isv with brake cleaner. also check the idle screw isn't missing or v loose Quote Share this post Link to post Share on other sites
big_mac 0 Posted October 17, 2003 i didnt think 16v's had an isv, i thought it was a g60 thing. Quote Share this post Link to post Share on other sites
dazzyvr6 0 Posted October 17, 2003 yep the 16vs had a isv,bit i thought 8v's had an auxilary air unit :? Quote Share this post Link to post Share on other sites
stoner 0 Posted October 17, 2003 Surely a vac leak wouldn't cause the revs to rise? Quote Share this post Link to post Share on other sites
Andy T 0 Posted October 17, 2003 Wind the idle screw right out, and clean the end of it, until its spotless. also clean the hole out. Made an amazing difference to my mk2! As Gazza says, clean the ISV, and if you can, leave it soaking overnight in brake cleaner or petrol. Quote Share this post Link to post Share on other sites
stoner 0 Posted October 17, 2003 The idle screw did seem a bit loose. Is the ISV part of the assembly that it screws into? Don't really know my way round that part of the car, never had to before! Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted October 17, 2003 The idle valve is the Bosch metal tube next to the distributor. Replace the idle speed screw rubber seal as these often perish and cause air leaks. The isv over-rides that screw anyway but idle speed needs to be set to 1000rpm with the isv disconnected. If it's an 1800 16V, get someone to set the base CO to 2.0% and it'll drive and idle a lot better. Kev Quote Share this post Link to post Share on other sites
stoner 0 Posted October 23, 2003 Tightening the idle screw seems to have doen the trick for now anyway, been OK 4 days and counting.... Cheers for all the help guys. Quote Share this post Link to post Share on other sites
