Running rich

[Evoman]

Hello,

I had significant issues passing the MOT last year that we believe was due to a failing but not completely broken O2 sensor. So if your car passed an MOT it can't be that bad

Mine was so bad when cold that it would make you gag and eyes water. Much better now but it's still a bit rich. I plan to get it mapped properly. Money going into house right now though, commitments eh...

To fix mine actually fitted a Wideband Lambda to aid future tuning as it wasn't too much more expensive. The car has an emerald so I was also able to trim the idle fuel down a little to help at MOT time. It worked thankfully.

Regarding IACV. I believe the VHPD one isn't common to other variants but don't quote me on that. It is known to stick though and it's in a rather unfortunate position.

As Dom says, I'm at KH this Sunday or next Saturday. Happy to talk over the cars. I've only had mine a year but been through s bit with it. It's quite different to the Elise I had before

Hey Ferg, seems it may be a similar issue. Mine 'passed' it's MOT and I do have the offer to head back to put it back on the emissions analyser. O2 sensor will be ordered tomorrow.

I spoke to Craig about it too and he reckoned not too much to worry about - it seems to run well. The 190 pack are a struggle to get through emissions as has been suggested.

Look forward to meeting up at Knockers - possibly on Sunday but definitely at the track day

[Evoman]

Cheers Robin, that's another helpful pointer. Is there an Elise / Exige parts catalogue or manual available from anywhere? Something that shows with a diagram where each part is located? I've seen something like that for exterior trim.

I haven't noticed any flamage out the back yet but then I've been mainly focused on whats ahead of me.

Misfiring - can't say I've noticed that either, on the MOT test at 2500rpm it just sounded sweet but angry and snarling, no missing at all that I could detect.

Great - a dodgy sensor better than a misfire

This is the parts manual page for the Exige S1 sensors:

http://www.deroure.com/images/diagrams/16/17_06.gif

It may be possible that there is a copy of the the Exige wiring diagram out there too ...

Cheers,
Robin

Robin, is that for the S2? Reason I ask mine doesn't have a coil pack, it has a distributor so the earlier version I believe?

[Ferg]

Your car should have a coil pack no? I didn't realise there were some out there with distributors. Just shows that you get to know your own car. That diagram is confusing on a number of points, least not that it shows a throttle butterfly that is just incorrect as they all had throttle bodies. Many of those sensor points are right though. Head scratcher

Oh and Exiges.vom is a great information source

[robin]

Are you sure it has a distributor - it shouldn't have - I have the original Exige supplement produced in 2000/03 and it has a coil pack; the engine is based on the 340R, also only available with coil packs. Take a look at your VIN - everything except the last 4 digits shows what kind of car you have.

There are only three ways I can see that an Exige has a distributor:

(1) It's had an engine & engine management transplant (the stock Exige ECU would not work without coil packs and was not reprogrammable).
(2) It's an Elige - that's an Elise with an Exige body fitted.
(3) The factory actually made some this way for some reason ... no idea how that would be though.

Your VIN should be something like

SCCGA111aYHF8bbbb

The G is the engine type, 1.8 K16 - there isn't a code for VHPD, so I think it will be G.

The A is seat belt type.

All Elise type cars are 111

The a is a check digit so doesn't matter.

The Y is model year 2000; if it's 2001 then it's 1, if it's 2002 then it's 2.

The H means Hethel (I think all Exiges were built in Hethel).

The F is chassis/body - F means SVA, but possibly it could also be E which means race, but I think those were the Motorsport Elise cars.

The 8 immediately before the bbbb means it's an Exige (other options are 3=Elise, 6=340R).

The bbbb is your vehicle's serial number - don't post that to a public forum!

Cheers,
Robin

[robin]

Your car should have a coil pack no? I didn't realise there were some out there with distributors. Just shows that you get to know your own car. That diagram is confusing on a number of points, least not that it shows a throttle butterfly that is just incorrect as they all had throttle bodies. Many of those sensor points are right though. Head scratcher

Oh and Exiges.vom is a great information source

It is an S1. The throttle it's showing is a huge plate that lives in the standard air intake path which, I think, was often removed, but was part of either some noise or emissions control. I think it's called the resonator valve.

[Evoman]

Robin, that is interesting. Are you the font of all knowledge for everything Lotus?!

You've got me worried now! No it's definitely an Exige and has the 8 in chassis number too.

The distributor thing has got me confused though. I think it has one, shows how much attention I've paid when looking in the engine bay but the reason I mentioned that was when in for an MOT there was a chap there that races in the MG cup series with VHPD engined ZRs and he said mine was an earlier VHPD without the coil packs and reckoned that was more reliable?

I'm nowhere near the car right now but I now feel I really must take a look soon as.

I do know that the car was originally a company car owned by the then Head of Manufacturing at Lotus who went on to became the MD and it was looked after by Lotus during its first year and a bit by Lotus technicians. I have spoken to him about the car which he remembers fondly.

RIch

[Dominic]

Robin, that is interesting. Are you the font of all knowledge for everything Lotus?!

Yes!!

I do know that the car was originally a company car owned by the then Head of Manufacturing at Lotus who went on to became the MD and it was looked after by Lotus during its first year and a bit by Lotus technicians. I have spoken to him about the car which he remembers fondly.

RIch

I know of someone else who has an ex Lotus management car, lets just say it is not quite the spec or model it might appear to be.

It's not unusual for the factory to make something off-spec, but more likely an owner along the way has changed something - would not be to concerned.

[Ferg]

The board time catching me out.

Yes, remember about the noise emissions plate now.

[Evoman]

They shouldn't over fuel that much if the O2 sensor is working correctly. My money would be on the O2 sensor being borked; it's easy enough to test with a multimeter once the engine is hot, assuming you can find the loom connector.

Bore wash might well be a concern if massively over fuelling. The other issue is whether it's over fuelled or misfiring. Both spew unburnt fuel out the exhaust ...

Cheers,
Robin

Robin

What values would I be looking for using a multimeter?

I'm going to take a look this afternoon and see what I can figure out

Rich

[robin]

Robin, that is interesting. Are you the font of all knowledge for everything Lotus?!

Nope ... just happened to have the manual to hand so had a look

You've got me worried now! No it's definitely an Exige and has the 8 in chassis number too.

That's the most important thing, value wise, so all good.

I do know that the car was originally a company car owned by the then Head of Manufacturing at Lotus who went on to became the MD and it was looked after by Lotus during its first year and a bit by Lotus technicians. I have spoken to him about the car which he remembers fondly.

Perhaps it's a bit of a special then ... Lotus, no two cars the same

Cheers,
Robin

[robin]

Robin

What values would I be looking for using a multimeter?

I'm going to take a look this afternoon and see what I can figure out

Rich

Hi Rich,

Sorry I didn't get back sooner - I don't get time to read this during the day.

The O2 sensors come in various forms - I think Lotus typically use a 4 wire sensor; there are two thick wires and two thinner wires; the thick wires are the heater wires and the thinner wires are the signal wires (also the signal wire/wires might be in a screen). The voltage across the signal wire pair should vary between 0.1 and 1.0 volts (or, -0.1 and -1.0 if you've got the wires on back to front ) when the engine is up to temperature; if you measure it with the loom plug disconnected you obviously have to measure on the O2 side. Once you've cracked open the connector you'll find the engine runs open loop and so you'll probably find the voltage goes up towards 1.0 volts and stays there (because the engine will run rich); if you manage to measure it with the loom plug still connected then you'll see the voltage fluctuate as the ECU adds/removes fuel to try and keep the voltage at 0.45v or so (the target voltage for perfect running).

Cheers,
Robin

[Evoman]

Brilliant thanks for that Robin - I'm going to check it tomorrow.

[Evoman]

Okay so ignore me I'm talking bollocks it has a coil pack set up not a disi. Really haven't got very far with this as my multimeter appears to have given up, can't even get the plugs out to look as the socket I have is too fat for the hole. I'll leave for the experts I think and get it booked in with Craig in Edinburgh soon tho I gather he has a bit of a lead time just now.

Thanks for the help!

Rich

[robin]

That is the most sensible route - you give them the car, they give it back working

[DDtB]

Let me know if you need a hand with getting it there Rich. I generally drive to Craig's every other Friday anyway ...


Sent from my iPhone 6 using Tapatalk