Topic

Hi everyone,
I have a trouble with my car, Lotus Elise S1 111S, VVC engine with MEMS 2J.
Trouble detail is that MIL Lamp is flashing and come to light in some case depend on thlottling after 30 min. driving.

To check and make clear what happened, I use PSCAN.
I found nothing except "Ambient temperature sensor error" which Elise doesn't equiped.
Even though, I do clear error and I have confirmed only "Ambient temperature sensor error" is in there.

After that, I checked Live data and I found follows.
-1. "MIL LAMP" is "on" even nothing error detected on PSCAN.
-2. "O2 sensor heater" is "on" even passed enough time after driving.
-3. Just IG on, not engine running case, "Thlottle angle" value showed strange, over range after quick thlottle oparation for example just like a quick racing from idle to 4000rpm

And, unfortunately MIL Flashing trouble after 30min driving isn't disappear.

Does anybody have ideas about PSCAN situation and know how to clear Vehicle's problem?

Flashing normally means the lambda probe is sensing over rich exhaust.

Thank you for replying.

"Over rich" means less air or much fuel than ECU expected, right?

Could you say the reason why such situation is happened?

Broken Injector or induction air leak or O2 sensor trouble?

Rich means too much fuel.

Hi,

I've not got to the bottom of my 111s issues yet so I wouldn't put myself if the expert category.... but I think the Elise 111s has one difference over the MGF VVC.

Lotus did a recall in c. 2001 and fitted a misfire detection system. It's located on the LHS of the boot and is labelled 'EFI Technologies'. I've not managed to get any information on the exact workings of the system but it loops into the cars loom using a supplementary harness in three locations:

Lambda sensor connector
Fuel injection connector
Coil pack connectors (1 and 2)

It monitors misfire conditions and cuts the power (limit 5,500 rpm) and illuminates the dash light if there are issues. Pscan obviously can't read this system but you may have an issue there.

Thank you for your comment.

My car have a EFI Technology ECU. Regarding your advice, it seems something related with this.

About my case, I can't feel any misfire but MIL Lamp is flashing and soon after the time change to lighting. During flashing, nothing strange behavior but once lighting like a 2 cylinder missing.

I'll check EFI technology ECU.
Do you have any suggestion?

What is an "EFI Technology ECU"?
I am curious.

Thanks, Philip

On the Elise S1 VVC a recall installed a separate misfire detection unit following some misfire/cat fire issues on the higher performance Elise variants.

As I noted below the unit links into the standard car harness in three locations. Based on some wider research I think the unit looks at spark ionisation and lambda readings to detect the onset of misfire and then limits the rpm or cuts off the offending cylinders but how in interacts with the MEMS to cut the cylinders if misfire is detected is a mystery to me, I suspect it cuts the fuelling to the offending cylinders by intercepting the signals from the Mems unit. Details on the device are sketchy; I've dropped Lotus a note to see if anyone can shed any light on how it operates but in the current circumstances I'm not expecting a response.

If the misfire unit is triggering I would start by checking the usual electrical suspects, connectors, HT leads, plugs etc. as any of these could throw it a curve ball.

If that fails you could disconnect the unit from the car and reconnect the lambda, injection and coils to the car harness to see if it makes any difference, the car will then run as it left the factory (and in the same configuration as the MGF VVC) but obviously without the protection the system was intended to offer. At least you can rule it in or out.

If you do disconnect the unit do make sure you label what goes where as the injection and lambda plugs are not interchangeable reducing the scope for error but the plugs to coil one and two are...…

Stuart

My car has extra? ECU at boot like attached. It's connected to O2 sensor, Injector and Coil pack.

That's right. Mems ECU in the engine bay, EFI technologies misfire unit in the boot.