Tick-Over At 500 Rpm

[BELOTUS]

Hi everyone,

 

I pretty new here, I'm from Belgium but really wanted the advice from the UK on the issues I'm experiencing with my elise S2 -rover 122hp from 2002.

 

Firstly when I bought it less than a year ago, the engine hadn't been started for a while, and runs rough on idle with misfires. Smells very rich out of the exhaust. It had a general service maintenance with spark plug / 2x coil / oil / air filter / cambelt change. It still seemed to miss a beat though. No loss of water but I haven't driven it.

 

The only fault code was the camshaft sensor, which comes and goes.

 

Now, after having the battery flat, we jump started it and every since it idles at 500 rpm. I have removed the IACV, cleaned it but can't see any parts moving with it connected, with the ignition on, engine off, I can't blow air through it. Maybe only works once started is activated.

 

Any ideas on the low idle and the poor firing? I'm hoping not a HG to change but iff so, I prefer to know it's that.

 

Thanks for your help.

 

Alex

[Steve J]

TPS needs resetting?

Lambda sensor?

Water temp sensor?

Manifold leak?

Old petrol?

[bunny_au]

When you progress the ignition switch from off to run you should hear the IACV buzz/ticking as it resets in preparation for starting. But I don't know if the S2 ecu does this but I know the later EU3 MGTFs do this as well. But I'd guess if you had ethanol fuel it will have absorbed bags of water or be stale. The other is that fuel residue can have caused one of the injectors to become sticky so it might be wise to use some injector cleaner in your new batch of fuel.

[BELOTUS]

Hi Steve,

 

TPS needs resetting? I have done this about 20 times, and it didn't change anything

Lambda sensor? The sensor has been changed as the ECU is telling me that it is too rich, wouldn't adjust the lambda value and I suspected the sensor. Have no effect on either problem.

Water temp sensor? Is giving a good reading on both the dial and the OBD2. the water got to 112 degrees on the motorway in stop-start  traffic at around 40km/h

Manifold leak? I haven't checked this one, and I'm guessing it is the older gasket too.

Old petrol? more than likely was, but I refilled when the tank was near to empty. It is probably worth emptying the tank once and starting off new.

 

Alex

Hello Bunny_au,

 

I do here a buzz, although being alone, I'm not sure if I here the fuel pump priming or the parts buzzing...

How long does it buzzz and reset itself? Like, do I have the time to switch onthe ignition and run to the IACV?

 

The injectors will have to be cleaned, I agree with you fully. I have an ultrasound bath, so I'll stick them in there.

 

I'll keep you posted.

 

Thanks

[Thomas Harborne]

Hi Steve,

 

TPS needs resetting? I have done this about 20 times, and it didn't change anything

Lambda sensor? The sensor has been changed as the ECU is telling me that it is too rich, wouldn't adjust the lambda value and I suspected the sensor. Have no effect on either problem.

Water temp sensor? Is giving a good reading on both the dial and the OBD2. the water got to 112 degrees on the motorway in stop-start traffic at around 40km/h

Manifold leak? I haven't checked this one, and I'm guessing it is the older gasket too.

Old petrol? more than likely was, but I refilled when the tank was near to empty. It is probably worth emptying the tank once and starting off new.

 

Alex

 

Hello Bunny_au,

 

I do here a buzz, although being alone, I'm not sure if I here the fuel pump priming or the parts buzzing...

How long does it buzzz and reset itself? Like, do I have the time to switch onthe ignition and run to the IACV?

 

The injectors will have to be cleaned, I agree with you fully. I have an ultrasound bath, so I'll stick them in there.

 

I'll keep you posted.

 

Thanks

Sounds silly, but check the battery terminals are tight if you haven't checked already. When i bought my s2 2001 last month it started, but didnt run very well, sometimes it wouldnt start at all. And the revs get bouncing up and down. Checked battery and the + lug had been overtightened and split. New lug on both cables and she fired up like a dream.

[BELOTUS]

Hi Thomas,

 

Thanks for your input. I checked the whole battery fixations and all seems to have good connectivity.

 

I also got my mate to turn on the ignition whilst I listen to the IACV, but nothing, no sounds, no vibration.... How can jump starting do this?

Just to be sure, is there any possibility that the ECU has bugged during the jump start and now needs a reflash?

 

Alex

[Alex B]

Hi Thomas,

 

Thanks for your input. I checked the whole battery fixations and all seems to have good connectivity.

 

I also got my mate to turn on the ignition whilst I listen to the IACV, but nothing, no sounds, no vibration.... How can jump starting do this?

Just to be sure, is there any possibility that the ECU has bugged during the jump start and now needs a reflash?

 

Alex

Have you tried a TPS reset?

[BELOTUS]

Yep. Tried it so many times and after no change, I did it waiting longer after powering down, I also tried it whilst disabling the immobilizer on the key as I coudn't hear the fuel pump working.

 

One stud broke on the exhaust manifold when we changed the lambda sensor so I have to remove the rear clam again. I had also purchased a PRRT thinking this was to be done. I'll make the most of the easy access to flush the fuel system completely and check the inlet manifold for a leak..

 

BTW, is it normal that the inlet manifold has faded on the right hand side towards the distri-belt? It is a sign of overheating?

 

Alex

[BELOTUS]

Hi to all,

 

It has been a while and I have just found some time to move on with this thread.

 

The IACV was blocked, I purchased a second hand inlet manifold with all sensors on it to keep as spares.   The replacement IACV works fine now, so idle is stable.

However, the exhaust gases smell  really rich. and the engine still misfires irregularly but all the time.

I changed the fuel completely.

 

Took off the inlet manifold to find the gasket melted...

This doesn't sound good.. has anyone else had this, and does it mean that the bottom end could have suffered too?

 

 

[russelld]

A compression test would be a good place to start.

[BELOTUS]

Hi Russelld,

 

I did this when I purchased the car. All was in the green and identical across all cylinders.

There doesn't seem to be any water loss, oil/gas odours in the water, but I do find that there is quite some smoke (or steam) coming from the exhaust on start-up for 10 min (idling).

 

I have an innovate LC-1 lying around, I could check the rickness but that won't set me forward. New spark plugs 1 & 4 looked sooty compared to the 2 inner ones, altough all brand new.

 

I swapped the inlet manifold with the 2ndhand unit and a new gasket : same.

 

Alex

[BELOTUS]

Hello,

 

After all this time, I decided to change the engine for a second hand unit, as I was afraid of the  HG  being gone with the burnt inlet seal.

 

Did the replacement, installed the PRRT which works fine, changed pretty much everything, went to start it up and it does the exact same thing : missing a fire here and there, & slight open throttle and it feels like a massaging chair.

 

I saw the 80 amp fuse has gone and I know that the alternator isn't provided any power so I'll have to check the regulator. It's running on 12V, now.

 

The only elements I haven't changed are :

- the FPR

- the Throttle body but did the initialiszation

- ECU reflash (how can I check that?)

 

It's driving me crazy, please help!

 

Alex

[BELOTUS]

Anybody?

[DeanB]

I have no idea sorry.

[BELOTUS]

Thanks Dean anyhow.

I'll put the computer back onto it, because I recall the ignition timing varying on tickover (stable at 10 degrees then moves a bit).

 

Alex