Next problem.

Site Subscriber Joined: 10 Jun 2004 Posts: 2317

40 odd quid from that link. I'm assuming that all the steam/antifeeze the dodgy head dumped through the exhuast would be the cause of the dud lambda (if indeed it is...)

Site Subscriber Joined: 10 Jun 2004 Posts: 2317

Chris H wrote:

. If it is switching but theres a lean reading then you have an air leak into the exhaust system. Somewhere between the head face and CAT.

How do i know what a 'lean' reading is? Just so I know as im gonna go out and have a look now

Site Subscriber Joined: 05 Apr 2004 Posts: 1141

Chris H wrote:

If you check the lambda's voltage you should be able to see if its being ignored or if its buggered. If its constantly at nearly 1V then the sensors working but its being ignored, which then leads us to why?

If the lambdas being ignored it must be that the wires are either broken (check the heater wires for 12V) or that the ECU hasn't kicked in closed loop running. What causes open loop running, either full throttle (look for a dodgy map pipe/sensor or the TPS) or CTS is saying the car hasn't heated up.

if the lambda voltage is stuck on 0.2V and doesn't budge its knackered. If it is switching but theres a lean reading then you have an air leak into the exhaust system. Somewhere between the head face and CAT.

Site Subscriber Joined: 10 Jun 2004 Posts: 2317

Hmm, think i may have found the problem, dodgy wiring leading up to the CTS. Went out earlier to a cold car, would start then die. Wiggled the CTS wiring and it started. Incidently, what should a CTS resistance reading be when cold?

Edit, mine reads 515ish ohms when put in a cup of just boiled water.

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

I really should finish that efi fault finding techy up. Its quite good but very, very long as the few that have seen it will agree!

Site Subscriber Joined: 10 Jun 2004 Posts: 2317

Yes, you should get it up, help people like me Laughing

Looking at your megane reports its old CTS read 600somthing ohms and haynes reckons it needs to be 300-370, so can i assume my CTS reading 500odd is faulty?

Mr Quoter-vator Joined: 16 Feb 2004 Posts: 7405

for 7 odd quid u can rule it out

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

haynes is a bit vague (crap in laymans terms) with any sort of sensor values.

Also its not helped by the fact theres 3 different types of CTS (same body and plug and colour) and theres 2 types of air temp sensor.

I can give you a cold CTS reading if ye want.

Site Subscriber Joined: 10 Jun 2004 Posts: 2317

Chris, Yeah why not. JB, i've stuck the CTS that was in the head i got off you back in, it worked for you, so hopefully no reason it wont for me Smile