Throttle Sensor?

[fleets]

Does anyone know what the purpose of a throttle sensor is? Or what the symptoms of a duff sensor might be?

[Martin_S]

It senses the position of the throttle, strangely, enough.

It then feeds this information the the engine management computer, which uses it (along with other information from other sensors) to decide how much fuel to feed the engine and when to fire the spark plugs.

[scuffham]

why do you think it's a problem?

[fleets]

Hi Scuffham, Martin S. I've been having trouble with my cat warning light illuminating, shortly after which the engine is starved of fuel and tries to stall. Switching off the engine and starting up again solves the problem for a few more miles... I could understand if it where a faulty ECU temperature sender, or a faulty oxygen sensor, but the garage want to replace the throttle sensor - which doesn't make a lot of sense me. Do you think it sounds likely?

[tortoise]

Interestingly I awaiting a replacement throttle sensor on my S2. Wilsons say they are getting some rogue readings from it though they can't be sure this is to blame for the intermitant idle problems. My MIL came on too but I don't know whether this was the cause.

>> Edited by tortoise on Monday 24th May 14:41

[scuffham]

fleets said:

Hi Scuffham, Martin S. I've been having trouble with my cat warning light illuminating, shortly after which the engine is starved of fuel and tries to stall. Switching off the engine and starting up again solves the problem for a few more miles... I could understand if it where a faulty ECU temperature sender, or a faulty oxygen sensor, but the garage want to replace the throttle sensor - which doesn't make a lot of sense me. Do you think it sounds likely?

what Cat light? - do you mean MIL light?

MIL light can come in for a multitude of reasons, without getting the codes out of the ECU it's impossible to tell.

I would assume that's what the dealer has done, and it's saying TPS sensor fault?

you need to ask them what the fault coded were, then look them up in the service manual.

[fleets]

Perhaps this is a daft question, but, MIL light? The light I refer to is desribed in the handbook as 'Catalyst Overheat Tell Tale'. It looks like a cat with a few heat waves above it and is positioned bottom right on the stack. Is this what is refered to as the MIL light?

[steff]

If its an S1 elise then its not the MIL light.

[scuffham]

if it's an S1, then unless you are in asia, it's not connected to anything?

[fergusd]

IT may be the 111S misfire warning light . . . if the car has had the misfire detection kit fitted . . . that being the case when the light goes on it's detected a misfire and shuts down 2 cylinders . . . IIRC . . . so perhaps not surprising it's stalling . . .

So . . .

Is the car an S1 111S ?

Fd

[fleets]

Suddenly it all makes sense, it is indeed an S1 111S. Thanks for the help all, i'll get that checked out.

[fleets]

I took the car to my Lotus dealer, suprisingly they weren't aware of this 'misfire kit' so were busy checking the cat until I told them that the warning light probably meant something else...

Anyhow, a new throttle sensor, spark plugs, some wiring checks, and a huge garage bill later - and I still have the same misfire problem. Being as this fault resulted in a full product recall a couple of years back I can only assume that lot's of owners have had similar problems? How have others fixed theirs?

[fergusd]

It's usually an HT lead or coil pack problem if not water ingress into the plug wells . . .

Is the 'dealer' you are using a drug dealer ?

'cos they cannot, surely, be a Lotus dealer . . .

Find someone who knows something, anything, about the car . . .

Fd

[fleets]

I don't have much luck with Lotus dealers. I have two options, because i can only travel so far with a sick car. One of those options has just had it's Lotus franchise taken away - that's where the car is now - and the other I wouldn't trust as far as I could throw. This second reputable dealer 'changed' my cam belt. Or rather, they invoiced for a cam belt change. It then snapped, a lengthy argument ensued, and eventually an independant source, at Lotus's request, verified that the cam belt was in fact the orignal, it hadn't been changed. I seem to have lots of similar stories!

Cheers for info about the leads and coil, the garage just called to say that's what they're replacing now.

[Bonce]

I don't know what is more shocking - the cambelt story or the fact that a Lotus Dealer hasn't heard of the misfire detection recall!