The Lotus Cars Community banner
1 - 20 of 28 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter · #1 ·
Hey hey - quick intro for my first post.

Coming from 7 MR2s, always been a lotus fan. Finally able to get one. Traded in a 19 Cayman for a 17 Evora 400 in July.

So far I've been able to do 5 AX events and one track day at Mid-Ohio. No real issues so far, I've been able to search LT for most of them (Leaking windows, brake sensor, door card). With a fresh set of RE71RS, the car really shines on the weekends.

This past event was on a very hot day and we ran in the hottest heat, mid 90s. After my 6th run I noticed idling issues. First the engine revved to 4-5k RPM while I was coasting directly after finishing. Blipped the throttled and it slowly settled back down but still very high, 2k idle. Turned the car off and packed up, on the way home, every stop the idle was surging, say 700-1k. Sport mode, Race mode and AC did not make a difference. No telltale lights or anything. After 20 minutes on the highway, the idle is no longer surging. Drove it today, no issues apparent at all. One-owner car with 9k miles, only mod is third cat delete.

I reached out to Gator in Indy and they've not heard of this. I wasn't able to find anything on LT either. I have an appointment with them for late next month, hoping to see if anyone has any ideas. I'm also 2 hours away in Cincinnati. I have other events scheduled, but if something is actually wrong, I don't think it's best to run the car.

Some pics for fun..


Car Wheel Tire Vehicle Vehicle registration plate
Tire Wheel Motor vehicle Vehicle Automotive lighting

Vehicle Car Automotive tire Hood Tire

Tire Wheel Car Cloud Land vehicle
 

·
Administrator
Joined
·
13,550 Posts
What OBD codes are you getting? I would suspect dirty MAF and or vacuum leaks if no soft codes.
 

·
Administrator
Joined
·
13,550 Posts
No codes shown using my OBD scanner.
Try cleaning MAF my bet is it's got oil on it. What mode are you in? Also if it happens again try switching between modes and see if there's any change.
 

·
Premium Member
Joined
·
9,479 Posts
IPS or manual. If IPS its a hot tranny.
 

·
Registered
2017 Evora 400
Joined
·
822 Posts
I had something similar happen to me, but I was just driving around back roads on a hot sunny day. I turned the car on and off and the problem went away. I then cleaned the MAF and spated deoxit on the TB and MAF connectors and the problem has not returned
 

·
Registered
Joined
·
4,990 Posts
Dirty MAF with 9k miles would be a symptom, not a root cause. Without more info, I'd say cleaning the MAF was harmless but did nothing. The rest time and ECU on/off did more.
 

·
Less is Better
Joined
·
3,332 Posts
I don't know that it's a MAF. It sounds to me more like an issue with a coolant temperature sensor or perhaps a throttle position sensor. What you should do is get an OBD2 reader and see if all the sensors are reading within normal parameters.

I've had a couple of 2nd Gen MR2s. Fantastic little cars. This one had a 3.0L V6, sounded amazing and handled great. I miss it.
 

Attachments

·
Registered
Joined
·
8 Posts
Discussion Starter · #11 ·
Symptoms seem like air in the coolant to me but I didn't see much info on here about that being an issue. It's also interesting that it appears to have fixed itself.

Tirerack has them in stock for OEM sizes. 285/35-20 & 235/35-19, rear is taller but fits with no issues.
 

·
Registered
Joined
·
463 Posts
Check all the carpet around the pedal. I’ve had the glue on the bulkhead panel come loose on hot days and stop the accel pedal from returning completely.

This could seem like high idle, but is really stuck throttle. Ideally, take that piece out. On S1 cars it would qualify as a floor mat.
 

·
Registered
Joined
·
4,990 Posts
Check all the carpet around the pedal. I’ve had the glue on the bulkhead panel come loose on hot days and stop the accel pedal from returning completely.

This could seem like high idle, but is really stuck throttle. Ideally, take that piece out. On S1 cars it would qualify as a floor mat.
Stuck pedal makes all the sense in the world. Just about anything else would throw a code, but a slightly stuck pedal just looks like driver input to the ECU. I had been wracking my brain trying to think of something that would cause the high idle without causing DBW issues or a code, and I completely missed something this simple.
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #14 ·
I checked the carpet on the bulkhead, looks fine, pretty far from the pedal. A mechanical issue would make sense but seems unlikely. Would this also cause surging idle? I'll definitely check the pedals if this happens again. Drove the car yesterday and no issues apparent.
 

·
Administrator
Joined
·
13,550 Posts
Back to MAF and vacuum leaks?
 
  • Like
Reactions: donour

·
Registered
Joined
·
463 Posts
vacuum leaks?
This was my next guess. Autocross->violent transitions->shake hoses loose.

If this were my car, I would configure my data logger to captured coolant temp, throttle, rpm, maf, and timing info. At least that gives you a place to start.

A cheap obd dongle and your phone mounted to windscreen will work too. Hit record when it acts weird.
 

·
Registered
Joined
·
217 Posts
Totally off topic, but I’m dying to know: what is a good lap time for you in your Evora at Mid-O? Or, maybe Putnam Park, which is equally close to Cincy? And on what tires?

There is very little hard performance data on Evora 400 models, and up. All of the car reviews talk about how the car feels, that it’s lively, engaging, responsive, etc. But not much in the way of hard numbers at the track.

Many thx!
Mike (in Cincinnati)
 

·
Registered
Joined
·
4,990 Posts
This was my next guess. Autocross->violent transitions->shake hoses loose.

If this were my car, I would configure my data logger to captured coolant temp, throttle, rpm, maf, and timing info. At least that gives you a place to start.

A cheap obd dongle and your phone mounted to windscreen will work too. Hit record when it acts weird.
What would explain why the problem went away the next day? Vacuum leak seems improbable unless it is somehow in a circuit that is only active when extremely hot idling.
One possibility is that there’s just a weird corner of the calibration, but I’d still investigate anything that could cause a sticky pedal.
 

·
Administrator
Joined
·
13,550 Posts
What would explain why the problem went away the next day? Vacuum leak seems improbable unless it is somehow in a circuit that is only active when extremely hot idling.
One possibility is that there’s just a weird corner of the calibration, but I’d still investigate anything that could cause a sticky pedal.
I sometimes wonder with our cars the degree of being ideal and having issues and being ideal. I had three intake manifold bolts and studs broken and yet still pulled a 258 whp with an insane high pitch whistle at times. Yet sometimes it acted perfectly normal. Once I pulled the intake manifold and saw all the gaps I was amazed it ran at all.
 
  • Like
Reactions: brgelise

·
Registered
Joined
·
4,990 Posts
I sometimes wonder with our cars the degree of being ideal and having issues and being ideal. I had three intake manifold bolts and studs broken and yet still pulled a 258 whp with an insane high pitch whistle at times. Yet sometimes it acted perfectly normal. Once I pulled the intake manifold and saw all the gaps I was amazed it ran at all.
How would you explain why blipping the throttle helped? It was too soon for the engine to have cooled significantly. To be clear, I am not being facetious but I am asking sincerely. Motors are relatively simple things in a complex chain. Break it down step-by-step and it becomes simple again. In the end, there is a root cause somewhere to be found.
 
1 - 20 of 28 Posts
Top