EXIGE With Emerald ECU - Cutting Out.

General General Lotus Talk
1

HI there,
Has anyone experienced a want to not idle when warm. Especially when putting the clutch in as you pull up to a roundabout or junction the car just dies. It then turns over a lot of times to restart, but when running it drives A1. I am on an emerald ECU, induction kit, new leads, plugs, cap and rotor arm. Everything ielse is spot on.

Can this problem be trimmed out via the ECU?

What has caused this ?

2

cap and rotor arm.

??? What happened to the coilpacks

3

It has the elise spec no coil packs, and then supercharged at Turbo Tech’s !!

4

Yes, something similar happened recently to mine.
Cleaned a and checked everything, including IACV. Changed the Lambda sensor, no luck.
Changed the IACV, same.

Read in some forum (can’t remember where) of somebody having the same problem and basically changing everything and it was still the same, when they discovered that it was actually the wiring going to the IACV.

Me, I discovered that when I have the IACV in place, but disconnected, it works perfectly!

5

Thanks for the reply, sorry for my ignorance but what is the IACV ?

6

Idle air control valve

7

Where abouts do i find this item ?
Have you a brief description of it ?

8

It’s below the TB’s in the Exige. I think Elises and Sports 190’s had them near the airbox.
Its function is to idle, as such, it takes air from the airbox, near the trumpets, moves an internal valve in order to keep a target RPM and passes on this air to the Throttle bodies, just behind the butterflies.

It’s the thing circled in red in the picture (barely).

[image]http://img.photobucket.com/albums/v629/Uldis/TBsandIACV.jpg[/image]

9

Can’t do better than Uldis’s post…but from the service manual:

“An idle air control valve mounted on the throttle body, is used to regulate the amount of air by-passing the throttle plate, and hence control engine idle speed.” (Elise specific)

“Idle Air Control (IAC) valve; mounted on the rear of the engine and connected by hose between the intake airbox backplate and ports in the underside of each inlet manifold tract” (340R & Exige specific)


“The engine ECM is an adaptive unit which learns the ‘optimum’ setting for the idle air control valve.”

Removal of the IAC valve (which was part of the kit robbed off the Esprit V8) was actually part of the official Lotus 340R 340PS/Tonne Pack, so it can’t do the engine any real harm, although it was not recommended for road use and it was noted that too low an idle speed may result in excessive HC emissions for MOT purposes. A noraml idle is quoted as 1,250rpm.

10

Thanks for that, GREAT pictures, and lots of help…

I have also spoken to Emerald, who have come up with another idea. They have suggested that there is a data learning process for throttle positions. This may have gone out of sink and need recalibrating. It is a process of hooking up the laptop selecting throttle POT and then pressing the throttle pedal all the way down in order to calibrate it correctly !!

Is this a posibility do you think ?

Will check the Idle valve also tomorrow as this is a very easy and more importantlt CHEAP fix !!