Starts but stops after 2 seconds

[wul]

year 2000 Elise 111S. Engine will start and run normally for 2 seconds but then stops. Was OK until I washed the car.
Cobra and Lucas 5AS immobilisers are allowing car to start and run, so does not seem to be an immobiliser issue.
Plenty fuel from return line when engine is running and petrol flow only reduces and stops after the engine stops.
Tried disconnecting battery and reconnecting after 30 mins. No difference.
Changed crank sensor but no difference.
Is there any diagnostic tools that will work on the VVC Lotus?

[mwmackenzie]

Dry out the plugs, this happened to me once before in my S1 111s, it was water in the plug bores in my case, I fitted an S2 engine cover to sort that issue out a treat....

[wul]

Had the plugs out and wiped leads/sprayed in WD40 but they were dry anyway. No water in mine. Still the same fault. Starts and runs normally for 2 seconds.
ECU removed and is going to sit on the boiler tonight.
I don't know which diagnostics work on the ECU but I have tried a Sykes Pickavant and an Autel Pro and they don't communicate.
Taylors in Aberdeen have Bosch KTS, Delphi DS 100 350 and an Autel Advanced tech 2. Taylors don't know if they will work until they plug in to the car and try. Does anybody know which diagnostic would communicate with the VVC type ECU?

[j2 lot]

Stating the obvious here, but have you checked the inertia switch?

[wul]

Thanks but it's not the inertia switch.

[steve_weegie]

Diagnostics for this ECU are a challenge - it's not OBD compatible and you'll need something such as the real Lotus scan tool, or perhaps Rover's testbook tool. I had a check of my Delphi tool, but this is 2001+ (S2) only as well.

The start for 2 seconds is reminiscent of immobiliser troubles however - I certainly know that the Rover ecu's will only run the engine for a few seconds if the immo isn't communicating with the ECU.

[wul]

I think I need to find somebody who can read the units to check they are working properly regarding the immobiliser signal. I could remove the 5as and send it to someone along with the ECU.

[les]

Try and borrow an emerald ecu from someone and see if the engine fires up, then you'll know if its electrical or the combination of ECU and 5as unit. I've got a matched MEMS 1.9 + by pass but not my use to your engine I'm afraid. As I said via IM, if it is the 5as unit, Dan (BobbyBrown over on RoverTech forum) can sort it out for you

[robin]

It is not trivial to fit emerald to vvc s1 due to not having the same connector.

Does it cut out even with a lot of throttle?

I suspect the ecu is not receiving the unlock code from the immobilizer module.

Given your immobilizer works otherwise I would be looking for a broken code wire.

Easy enough to test with a scope and wiring diagram. Assuming you can locate the wire at ecu end hook up scope, turn on ignition then clear immob. You should see a data burst at this point.

Cheers,
Robin

[r10crw]

wullie, i have a scope you can borrow

[wul]

Gone offshore. Thanks for the info so far. I will get back to the investigation when I return.

[wul]

Craig - Thanks, I will borrow scope when I get home. I just need to find a white lab coat.

[wul]

Lotus fixed. If your fault symptoms are the same as mine - starts and runs normally for 2 seconds - it could certainly be the Lucas 5AS immobiliser/ECU. Replaced my 5AS and ECU with a set off Ebay. Fault now clear. Only thing is I now have Rover fob button to press as well as the Cobra.

[wul]

Turns out I dont need to press any buttons on the square keyfob. Just press the button on the Cobra fob as before and thats all I have to do. Dont know why I dont have to use the square fob too but its all good.

[robin]

Keep the square fob handy - you might need to press it after, e.g., a flat battery.

Cheers,
Robin