11 replies to this topic

[un1eash]

Just when I thought id fixed my running issues the car still has a misfire problem. I pulled the plugs and there all half white and black indicating some kind of ignition or fueling issue.

If you hold the revs around 2k rpm the exhaust pops away which isn't right on a standard 111s.

I tried replacing one coil with a cambaire part but that made no difference so I don't think its a coil issue. I'm going to try some injector cleaner but other then that I don't know what to do anymore.

It's had new plugs less then 500 miles ago and new ht leads. The other thing I need to check is the compression, the headgasket was done before I bought the car.

[jimbo07g41]

The s2 111s tends to go through TPS sensors also and this can cause mis fires.  I have had replace mine twice but this did show up with a MIL.

[un1eash]

I do get a mil light every now and then and the codes say misfire on all 4 cylinders. This also makes me think its something other then plugs or coils as its happening on all cylinders.

[jimbo07g41]

If it was a coil you would only get it on two cylinders.  If you have put on new leads, I would suspect the TPS.

If it was mechanical, it would be rare that you get a misfire on all four pots.  More likely electrical.

On the 111s I would be looking at TPS and Battery.

Edited by jimbo07g41, 06 March 2013 - 07:57 PM.

[un1eash]

Checked the tps using my Bluetooth obd2 reader and it shows a nice linear 0-100%.

My long and short fuel trims don't seem right though, one of them is around 30%

[jimbo07g41]

Hmmm,  you thinking one of the o2 sensors is on the way out?  Might explain it running so rich.

[un1eash]

Will have to do some more tests and see what fuel trim and o2 voltages I'm getting as they seem outside of normal spec.

[un1eash]

I've been advised to check the earth straps. Just had a look for them and I can't see them anywhere. Where are they? There's meant to be a mount on the chassis somewhere that connects to the ecu plate and the gearbox.

[Martin R]

Its virtually directly below the L/H gearbox main mount. on the chassis inside the engine bay. Approx 9 inch below the top of the mount. You should just see the braided earth strap coming off the gearbox and onto the mounting point. There should also be a few other wires connected to it.

[un1eash]

Thanks, is it accessible from the top? Car is in the gargae with limited space on that side to look for it.

[Martin R]

un1eash, on 07 March 2013 - 07:27 PM, said:

Thanks, is it accessible from the top? Car is in the gargae with limited space on that side to look for it.

It will be a lot easier from underneath on ramps with the 2 rear undertrays removed. I would undo the bolt remove all the connections, clean the chassis and all the lugs. Bolt it back together and cover in vasaline. Also check the connection onto the gearbox and clean it up.

[un1eash]

Thanks again,theres something to do this weekend if it stops raining.