Stutters at 5000rpm?

Just caught this off the Lotus site:Nick AdamsMember posted 15 November 2001 13:29 --------------------------------------------------------------------------------Hi Xavier, I guess which box you go for depends on what you want from the car. I am currently using a 190 Exige with the UCR box as everyday transport (looking for the misfire…)and it’s [email protected]@dy good fun. Having said that I’m glad I haven’t got it too long as I don’t think my licence will stay clean very long with that performance on tap. The car revs at 4000rpm at 70 mph in top which isn’t too noisy but it would get tiring on long runs I guess. Against that, the improvement in acceleration is fantastic, and the overtaking ability almost unbelieveable. As far as engine wear goes, higher revs will lead to more wear obviously, but the magnitude of this is tiny in comparison to how the car is driven. I wouldn’t expect it to make a significant difference in the real world, to be honest. The effect on fuel consumption is slightly more moticeable though…Cheers, Nick Nice to see someone serious is looking at the problem…

Thanks Steve, your post caused me to re-read this thread and I noticed this. quote:Originally posted by Ken Pegg:I have had the same problem that Hythe describes and apparently it is not unknown with Elises. Basically it arises from restarting a hot engine. Petrol vapour forms in the fuel line giving an intermittent fuel supply, also known as ‘vapour lock’.Do those of you with more technical knowledge than me have any thoughts because it would appear that this is an area that has not been sufficiently explored. I personally am not convinced about the leads but then again if it was fuel why at 5600rpm?While you technical boffins are pondering this one please give some thought to my clutch cos that has me confused as well. [image]http://www.exiges.com/ubb/NonCGI/images/icons/confused.gif[/image]

I think there are three problems here:1. Leads/connections: My machine was way better when I installed the Mangecours. I had an eractic misfiring caused by dodgy connections. Made worse by the “water in the plug hole” issue.2. Vapour lock: A well observed problem. I’ve had it a couple of times on heavy track sessions where I haven’t done much of an in lap. Problems on idle, generally eratic behavior - OK if you keep the revs up. Basically fuel starvation.3. This stutter thing. Occurs exactly at 5500, does it three times. Mine seems to do it more when cold/damp. Never goes until you “reboot”. Has to be dodgy software. Some particular set of variables/conditions causes some the machine causing a problem.Is anyone getting this problem with Emerald ECU’s - is this a problem with 177 and 190’s too?Should we get a bit scientific about it to help out?

Matthew, I have not had any of the above, exept when my (Lotus)leads popped off. Maybe Lotus should buy their leads & ECU’s off Magnecour and Emerald?

Every Lotus owned car I’ve ever seen has Mangecour leads.Do we know if this is an issue on 190 340R’s?[This message has been edited by Matthew Treagus (edited 23 November 2001).]

Yes. IIRC most 340Rs on the egroup have switched to Magnecors. They can still pop off but do so much less frequently. Interestingly the ECM map on my 175 340R was changed to the Exige map to eliminate misfiring! The misfire soon came back when the standard leads popped off so I changed to Magnecors which I’ve been using on my Elise for years.

Although I had several other problems yesterday at Elvington, I also experienced the dreaded stutttttt…er at 5-5.5k revs and I know that Shaggy also had a similar experience (how about you Matthew?).It only happended on one session and dissappeared by the time i started my second…I didn’t even bother trying to push down the ignition leads (OK I forgot with so many other issues to deal with!).I only have the standard leads fitted but in casting around for a new battery came across a possible alternative for those keen to move away from the standard leads: Lumenition ‘Blue’ ignition leads �42.50(inc VAT & UK delivery) These leads are unique, as far as we are aware, in that they are the only suppressed leads in Europe which are manufactured with 100% silicon insulation, rather than just a silicon coating. This gives them superior insulation characteristics and improved reliability even in Extreme conditions of temperature and humidity. They are also capable of firing up to 20% higher voltages than can ordinary silicon coated leads, which use EPDM insulation. The 8mm diameter ignition lead cable is specially manufactured to our specifications to fit the Lotus Elise S1 or S2 perfectly. The kit includes four ignition leads and a coil lead.And lastly they do of course look great!This product has a 5-7 days delivery time.Available from http://www.race-speed.com/ Will match the blue hoses on the breather kit better than the red Magnecours (if thats not too anal!!!)

My Exige behaved very well yesterday. We ran it pretty hard too - two drivers running in two sessions in the morning and most of the open-pit lane.I’m running the Mangecours but still get the 5,500 issue from time to time. I’m convinced that its the coil overheating problem. Seem more common after a spin or stall.

Re the stutter at 5500rpm - after suffering from a similar problem at Elvington yesterday - mine proved to be a bad contact between the end of the plug lead to the plug, somehow water had got into the port and over time had dried out causing poor contact, hence misfire. I cleaned off the plug and HT lead and hey presto, no misfire!! [image]http://www.exiges.com/ubb/NonCGI/images/icons/tongue.gif[/image] [image]http://www.exiges.com/ubb/NonCGI/images/icons/tongue.gif[/image] [image]http://www.exiges.com/ubb/NonCGI/images/icons/tongue.gif[/image]

Ah but S111AGY, you had also switched the engine off & left it for a while - another cure for the “mysterious stutter”, said Grrrrr, Grrrrrr, Grranville [image]http://www.exiges.com/ubb/NonCGI/images/icons/smile.gif[/image]On the official Lotus bbs site, Nick Adams has confirmed that Lotus recognises that there is an intermittant misfire problem at 5500 rpm & that “they are working on it to find a solution”.In the meantime, just regularly check that the leads are seated properly, & if it does re-occur, switch off & leave for a couple of minutes. Magnecour leads do help keep these annoying occurances down to a minimum [image]http://www.exiges.com/ubb/NonCGI/images/icons/smile.gif[/image]PS many thanks for the barbie lunch yesterday - no after effects, so you won’t be hearing from my lawyer [image]http://www.exiges.com/ubb/NonCGI/images/icons/wink.gif[/image]

The water build-up arround the plugs is caused by rain coming in through the engine bay air vents and leaking round the plastic cam/plug cover in-fill. It happens on Elise and Caterham Se7en’s as well. The cure is to modify/fit the cover from a Mk2 Elise. They have a ‘Lotus Performance’ logo and only cost arround �12Rob Gibbons

& Haydons said on Wednesday stutter is caused by the sensitive ignition coil Lotus chose that doesnt like heat or vibration - which is mounted on a vibrating plate too close to engine/exhaust.They also said yip was nylon / metal joint on some half shaft ball joint thingumybob or in some cases relief valvy thing in dampersAs you can see I understand these horseless carriage things -

& somebody - not mentioning any names - needs a new exhaust cos the stuffing is hanging out of his Clue is it’s parked in Salsbury…

Hi all (new member) My Exige developed the same engine stutter at around 5500rpm. The problem was hard to solve due to it was intermitant and would never rear its ugly head when i took it in to lotus. Eventualy i found out that lotus were doing a recall on the Ecu’s of Exiges that had this prob and basically they just replaced the Ecu with a differently mapped one and i have had no problems what so ever. Even when i have caned the car at trackdays where it usually shows up the next day.

well had a major problem with this yesterday at Rockingham…started in the 1st session and lasted all day. tried all the usual tips , including removing plugs and cleaning/checking and nothing fixed it. Seemed to be heat related in that it was Ok for the 1st lap of each session and then just as you came onto the pit straight it would happen every time…Might try and check out the wheel sensor over the weekend and then just give it a blast and see if its reset itself…otherwise I think Im in the market for a new coil!

Steve, can you rev through it? If not, see my problem with the fuel pickup pipe…

Russ - no it was impossible to rev through it…seemed much worse than when hitting rev limiter - I did think of your problem, will leave the car on trickle charge for a week and try it next weekend…hoping it might just go away on its own!

Steve I had the same problem a few weeks ago after having the 190 upgrade. I could drive for a while then the sensor would cut in and cut the revs, I took the car back to Nick Whale who changed the chip but still showing a misfire eventually changed the coil and now the car is a different beast [image]http://www.exiges.com/ubb/NonCGI/images/icons/grin.gif[/image]They thought the coil may have been faulty for some time but the new misfire sensor in the re programmed chip has highlighted the problemJohnC [This message has been edited by JohnC (edited 16 March 2003).][This message has been edited by JohnC (edited 16 March 2003).]

See my other post re: my Goodwood stutter incident… wheel speed sensor (mounted on the offside rear) is critical for post-recall ECU’s. Poor connections will cause the “get you home” rev limiter to cut in.

hi everyoneright, i am really starting to worry bout my car. picked it up on thursday from storm in leicester, and although it is the most beautiful thing in the world it will just not rev past 5600 no matter what, just stutters and i cant rev through it, ive tried the leads and they all seem to be on correctly, but ive also noticed that it drops idle to around 600 rpm and slowly goes back up to 1250 all the time but very slowly. any suggestions, also does anyone elses steering wheel judder quite badly at around 85 mph is it the tyre size and rack gearing or just my badly balanced wheels.please help…giles