Warm Idle Problem

[ashje]

Ok so my car runs fine when cold and getting up to temperature just when the needle starts to hit the centre it will occasionally hunt and sometimes die and it also sounds as if its misfiring on low throttle.

Now i have checked just about everything, but one thing i am unsure about is the IAT, i am using the standard m50 one as i have done a m50 manifold swap. The plug which goes onto this where is it suppose to come from? There was one connected on the MAF bit of the loom and another two on the main bit of the loom, one being much longer( assumed this to be gearbox related for reverse light)

I actually used the shorter one on the main bit of the loom for the IAT and stupidly cut off the one on the MAF bit of the loom. Can anyone tell me if i have used the correct one and if i have will the m50 IAT cause the issues i have and will it be worthwhile putting an m52 one in.

My crankcase vent is currently going to atmosphere, will this cause any issues? ( There's no hole in the intake boot going to atmosphere too!)

Thanks
Ash

[ashje]

Two grey wires are going to the IAT, i've tried an m52 IAT in the intake elbow with no luck.

[DanThe]

The one you cut off the maf section of wiring is not needed, so dont stress about it
The reverse switch wire is Blue/Yellow, and Green/White, cut it out
Air sensor is the only other long 2 pin plug left, M50 or M52 it wont affect the running

Have you changed the black 4 pin coolant temp sensor?

[ashje]

I changed it earlier and at the same time i pulled the plugs, all 6 were full of soot. After i cleaned the plugs and plugged a different(although not new) 4 pin coolant sensor in it now misfires more often and at lower engine temperatures.

Maybe time for a brand new sensor?

[DanThe]

Have you fitted new plugs since you have had the engine? Very unlikely that 2 sensors in a row are bad, TBH ive never had to change a bad 4 pin black sensor as found on the M52

[ashje]

Yes i have put 6 new Bosch plugs in when i first started having the problem, they made no difference.

One other thing haven't done is swap out the o2 sensors, so i'll get on that tomorrow.

If it's not that i'll wire in the Diagnostic port and see what that brings up (it came detached from the loom)

[ashje]

Actually come to think of it, the round plug which sits next to the c101 is a diagnostic port isn't it? How does it differ from the square OBD plug in what it can be used for?

[DanThe]

It is yes, you just need an adaptor to change from the square plug

[ashje]

Excellent, hopefully this will all be sorted soon .

Thanks

[ashje]

So a diagnostic test has revealed a few things, faulty lambda's and cam sensor.

With regards to the lambda's, i have wired both into the one wire on the c101 plug, is this correct?

Another off topic question, my EWS works but very weirdly, if the key is in the ring it will work, if i then remove it the car will still start. But if i leave the key out of the ring, disconnect and reconnect the batt the car won't start :/