jas Posted May 17, 2014 Report Share Posted May 17, 2014 Had car out last night for run up the glens and noticed my idle speed started to creep when the car gets hot....it's about 900 when cold but as it heats up it creeps to about 1200 doesn't (so far) go above about 1200...any help appreciated , Regards Jas Quote Link to post Share on other sites
Steves_TR6 Posted May 17, 2014 Report Share Posted May 17, 2014 Perhaps an air leak ? Quote Link to post Share on other sites
RobinTR6 Posted May 17, 2014 Report Share Posted May 17, 2014 Do you set the idle speed when the engine is fully warmed up , if not try that first. Quote Link to post Share on other sites
jas Posted May 17, 2014 Author Report Share Posted May 17, 2014 The idle speed has been fine but I can't adjust the idle back any more, would air leak not show up when cold as well though? Quote Link to post Share on other sites
Jhurd Posted September 23, 2019 Report Share Posted September 23, 2019 Wanted to start this back up again and hopefully get a little bit more insight. Not sure if you found the source of the problem @jas? Recently purchased a ‘76 TR6 and I am having the same issue. The hotter it gets the more the idle speed creeps up. Again, starts off around 800/900 and after a couple of short trips ends up idling around 1800 rpm... any thoughts/suggestions would be great-thanks! Quote Link to post Share on other sites
Stagpowered Posted September 23, 2019 Report Share Posted September 23, 2019 Start by making sure all the butterflies are closing properly, the CR throttle linkage can be a pain to set correctly as there is a degree of twist in the linkage from where the cable attaches. Having got them all to close properly you should then be able to set the idle speed with the air bleed screw. then all you have to do is get all three sets to open at the same time as well, best of luck! Neil Quote Link to post Share on other sites
tr6tuga Posted September 23, 2019 Report Share Posted September 23, 2019 Sticking trotle cable? Wrong routing? Ask me how i know Quote Link to post Share on other sites
John McCormack Posted September 24, 2019 Report Share Posted September 24, 2019 (edited) On 5/18/2014 at 5:40 AM, jas said: The idle speed has been fine but I can't adjust the idle back any more, would air leak not show up when cold as well though? That road is very wide, but very short. :-) Edited September 24, 2019 by John McCormack Quote Link to post Share on other sites
Mike C Posted September 24, 2019 Report Share Posted September 24, 2019 Have you checked your manifold vacuum at idle? I use a vacuum gauge on the brake booster line. I know from decades of measurements my engine has to have 10 inches of mercury at idle on the airscrew. If I can't reach that level with the idle air screw I've got a leak somewhere. Note: my engine has had a lot done to it over the years- your engine may need to reach more than 10" Hg when idling without a leaky manifold. Quote Link to post Share on other sites
Robert Price Posted September 24, 2019 Report Share Posted September 24, 2019 I agree with Neil, if you have stops on the butterfly brackets slacken them off, if not just press each one with the engine running. I recently took SU's off a 6 and refitted an injection system and had the same issue. Just one inlet was responsible for increased tickover I could not believe how minute the movement was. Rob Quote Link to post Share on other sites
rjb2968 Posted October 11, 2019 Report Share Posted October 11, 2019 All, The creeping hot idle speed is almost always the bypass valve. Most people simply install a solid gasket that blocks it from working. Quote Link to post Share on other sites
iani Posted October 11, 2019 Report Share Posted October 11, 2019 On 9/23/2019 at 11:04 PM, tr6tuga said: Sticking trotle cable? Wrong routing? Ask me how i know I had the same creeping idle, mine too was caused by a sticking throttle, however in my case it was due to the throttle pedal shaft being worn and it was catching, a replacement assembly fixed it. Quote Link to post Share on other sites
Peter Cobbold Posted October 11, 2019 Report Share Posted October 11, 2019 Over -retarded spark ? Quote Link to post Share on other sites
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.