Cars a bit stuttery. Any ideas?

[Dundeesfinest]

Afternoon all. Another quick question re an issue im having without the S2 Elise. For about a week now the car has been running a bit stuttery. It happens when u accelerate. The past few times ive ran the car quite low on the red and my initial thought is ive maybe dragged up much from the bottom of the tank. Ive ran redex through it as well as changed the fuel filter but its still the same To top it off the engine management light came on for a few days but is now off again. Any ideas as to what to try next? Other than this the car runs fine, no loss of power and no stuttering other than when accelerating up through gears.

[steviej]

Plug, lead, or dampness in the plug holes maybe ?

[r055]

i had similar when i had new leads and coil pack fitted. The new leads were slightly longer than the old ones so they were a bit slack running under the plenum area which meant they were closer to one of the sensors than normal, causing electrical interference.

Give all your leads a good check for condition and routing

R

[BiggestNizzy]

My money would he on damp plug holes

[Dundeesfinest]

Thanks for all the suggestions. Will wait till tomorrow till this rain has dried up and check what's been mentioned. Just thought it odd that after running car for about 45/50 miles on the red (twice in a row ) it starts to stutter.

[robin]

Is it VVC or K16? I'm assuming S2 as you say "without the S2" but reckon you meant "with the S2"?

With the S2 elise it's unlikely to be the plug leads/plug bores as it has plug-top coil packs with all the HT gubbins buried underneath a rain cover that actually works.

It could be any number of things. First port of call would be to get the codes read out of the ECU and check the live data to see if any sensors are reporting bollocks values (e.g. failed O2 sensor, TPS, coolant temp sensor, etc.). This should be pretty cheap and any respectable garage should have an OBD2 data reader by now so you can get it done anywhere you trust. Post up the findings if it's not obvious from the results.

If the OBD2 shows nothing, pop the spark plugs out and look for variable deposits - anything shiny is evidence of water ingress into the chamber, either failed inlet manifold gasket or failed cylinder head (unlikely).

Cheers,
Robin

[Dundeesfinest]

Ok well firstly apologies for the delay in updating this thread. A week in Liverpool was followed by a week in Glasgow with work so I am justhome and able to update now. Where do I begin.......

ok well I called the AA out on Easter sunday as the stuttering was getting worse. The came back to me with the computer was reporting a mis-fire in cylinder 4. He said it could be coil pack or plugs (both of which were replaced by Roadboy in Jan so should e totally fine) He didnt have a coil pack to put on but checked the plugs and leads etc and said all was in order there. When I said both coil packs had been done in Jan he also thought it would be odd to be that so soon. I advised him that I had run the car for aout 40/50 miles on the red on two occassions over the previous 2/3 weeks and he then said i might of blocked the injectors? He advised running and engine flush through which I have since done but the car is still stuttering away. Runs fine on the motorway once up to 70/80mph but when you first start it up or if your running about in town etween 20-40mph its stuttering like made. Somethings not getting through cleanly somewhere but Ive no idea what. The engine management light also comes on and goes off again at regular intervils. Im at a total loss as to what it an be. Only person I trust working on the car is Dan (roadboy) but he is a fair distance to go (plus a week or so if im lucky without a car) if this is something simple that im just not getting. You need to forgive me, as much as I love my lotus I am not car/mechanic minded at all. In answer to robins Q the car is a type 23 S2 53 plate so Im thinking its a Rover engine.

Any further suggestions would be greatly appreciated.

Cheers

Derek

[Rich H]

If the Management light keeps coming on you should be able to get a read of it and it'll tell you what the ECU thinks it is.

Are the plugs looking OK? None of them a funny colour?

[Dundeesfinest]

If the Management light keeps coming on you should be able to get a read of it and it'll tell you what the ECU thinks it is.

Are the plugs looking OK? None of them a funny colour?

All the AA said was it was a mis-fire in cylinder 4.........he initially said coil pack and or plugs but when I said both had been replaced in late Jan 2011 he didnt seem to think either would cause problems so soon. He did then check the plugs and say that they were all fine.

[roadboy]

Derek,

I might be up your way in the next week or so if I get a tow car sorted out.

I'll give you a call if I am and I'll drop in and have a look.

Cheers

Dan

[robin]

Is is losing any coolant?

Cheers,
Robin

[r10crw]

Can the rover ecu determine if it has a misfire on a particular cylinder?
Either way I would still be looking at lambda with the above symptons. I had the exact same symptoms on a VX220 couple weeks back, EML came on just twice but thankfully stored it in the ecu, replaced it and the world was full of happy bunnys again.
Craig.

[roadboy]

Its a Lotus K4 ECU on the S2 Craig and yes it can determine misfires on individual cylinders.

Dan

[Dundeesfinest]

Derek,

I might be up your way in the next week or so if I get a tow car sorted out.

I'll give you a call if I am and I'll drop in and have a look.

Cheers

Dan

Cheers Dan, even if your remotely local I will happily drive to you so you can give it a quick roadtest to see what you think. No sign of any leaks Robin. It does seem to be more stuttery first drive of the day. Management light is currently off again. Might try a stronger flush?

Cheers again guys for the replies.

[robin]

If it's a warming up thing then temperature sensors and lambda sensors are both likely candidates. A proper OBDII reader will show live data from all the sensors to help eliminate anything broken. I'm sure Dan has one, as will most any competent garage of any type these days.

Cheers,
Robin