Can anyone help?

My St185 started runing on 3 cylinders yesterday, i could smell something burning and found the lamba sensor insulation melting. Today i replaced the sensor, but it still runs on 3 cylinders and the engine management light is still on. Anyone got any ideas what the problem is, i just got it on the road this Monday.

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Exup

Exup,

Have you checked the error codes to see what the system is flagging up?

That is always a good place to start, failing that have you checked the obvious things such as your spark plugs?

If you need help on checking error codes i think our site http://www.gtfours.co.uk/ has the process under the how to section.

HTH

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Loosey
Loosey@gt4dc.co.uk
Storm Blue JDM ST205
Super White JDM ST205
http://www.gtfours.co.uk

Some people are like a Slinky .. Not really good for anything, but they make you smile when you shove them down the stairs!

I have checked the spark plugs, they are ok, im going to replace the leads next.

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Exup

Have to agree with Loosey here...first thing to do, before replacing things, is diagnose the problem flagged by the engine check light.
It is relatively simply to do - a peice of wire bridging a couple of terminals in the diagnosis box/unit and counting the flashing of the engine check light in the dash.

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Vice Chairman
1990 White UK Celica ST185 - Project DTM
1997 Cream BMW R1200C (as seen in James Bond "Tomorrow Never Dies")
2005 Jaguar X-type 3.0 Sovereign AWD Automatic
Blood Bikes - https://www.freewheelers.org.uk/

I have checked the fault codes that flashed, 22 open or short in water temp, sensor signal (THW) 35 open or short in turbocharging sensor pressure signal (PIM).

Is this enough to stop it working on 4 cylinders?

I have replaced the leads today, no difference in the runing (3 cylinders).

What do i do to get it runing on all 4 cylinders?

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Exup

Sounds like a wiring fault, maybe an earth fault.

From the top of my head, there's a heavy earth from battery to gearbox, another from battery to body, and one from the alternator to body by the o/s suspention turret. Also, there's an ECU earth on the underside of the inlet manifold which comes out of the bottom of the wiring loom which runs across by the injectors.


From the melted lambda sensor, I'd also say theres a possibility of a burned out engine wiring loom. If one cable overloads & melts it tends to melt loads of wires together.

Have you been doing any work on the car recently which could have disturbed the wiring ?

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If at first you don't suck seed, try drier grain.

I will check the earths, engine was replaced 2 years ago, i will look at the earths.

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Exup

I think i have found the problem, one of the the temperature switches on the water outlet pipe has broken along with a sensor wire. There is quite a few sensors on this pipe, unfortunately my Toyota dealer doesn't list it, as his computer only shows a english market st185. One of these sensors is £75 i have orderd one but not to sure if it is the correct one as my car is a JDM.

I hope i haven't damaged the engine.

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Exup

I doubt you have damaged the engine... this picture might help, it's from a 165 but the layout is very similar on the 185...

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Kris
95 ST205 - slept for 10 years, now waking up...
Avensis
http://www.gtfours.co.uk
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Turbocharging - the replacement for displacement

Thanks for the picture, it's the EFI water temp sensor that has broken. The wire to the water temp gauge broke, but i have now repaired that.

Do you now if the St205 system is the same?

Thanks for your help!

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Exup

The 205 is a bit different... not CSI (Cold Start Injector).

"Think" the 205 only runs one sender for temperature...

There is no BVSV on the 205 either

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Kris
95 ST205 - slept for 10 years, now waking up...
Avensis
http://www.gtfours.co.uk
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Turbocharging - the replacement for displacement

You might want to post in the wanted section on here Mate. I, for instance, have loads of 185 bits and bobs and would likely give you a sensor if you needed one!

You have to wonder why the lamda wire melted don't you? I have never seen one melt except from overheating as they carry no current in a single wire 185 type probe. Funny you don't have an error code for the lambda too and none of the faults you have found sound like they would effect only one cylinder!

I was also concerned about melted lambda sensor, I was assuming it was a type with built in heater as some 185's had these AFAIK. Could also be an indication of very high EGT which may have caused engine damage.

If you have the ability to do a compression test it would be worth doing to diagnose melted piston / broken ring/ringland or burnt/broken valve.


Worth doing the easy stuff first before assuming the worst.

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If at first you don't suck seed, try drier grain.

The lamba sensor insulation started melting, i've replaced it with the exact type, i have another one with more wires from a St205. I thought it was going to be a simple repair, but i started looking at the fault codes and a better look around the engine bay and it just doesn't look 2 b a simple problem to resolve.

This car was only put on the road last week with my engine from my old scrapped St185, it was runing fine in that!

I have run the car without number 1 plug in and i appear to be getting a lot of compression being compresed out of that cylinder. I will have to do a proper job, fingers crossed it's not terminal engine damage as i'm unemployed!

I have orderd a replacement part, just hope it's the right part and in future ask on the forum if anyone has the parts i require.

Thanks for your help guys!

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Exup

I have done a compresion check on all 4 cylinders and all 4 clinders are kicking out 153 psi. As this is the case i dont think that the engine is damaged.

So i hope tomorow that the sensor i get from my Toyota dealler might go somewhere to resolving my problem. But their must be more to this than just replacing the efi sensor and soldering the water temperature wire together.

I have checked the earth wires, all ok.

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Exup