TF 135 2004 running rich and stalling when could

Hi all,

our TF 135 is playing up after a cold start (mornings) it starts perfectly then after 30 odd seconds the revs drop to arround 900 and it smells rich from the exhaust and starts to chug a bit. It drives fine but stopping at a junction and it wants to stall. Sometimes it does stall and it's quite difficult to get it to start again.

Once it's up to temperature, it is perfectly fine.

I have a T4 and nothing is coming up as being out of spec. I've readjusted the IACV, no change, new lambda, no change.

Any ideas what's going on ?

Pete.

Hi . There are two switches ( thermistors) that control different areas on the TF but you will need the engine access panel off to reach them . One controls the temperature gauge and the other sends information to the engine ECU to control the fueling and engine fans . I would be looking at the the wiring and the switch. I think the one that sends info regarding the fueling is brown in colour and they tend to give the wrong info regards fuel enrichment if the terminals are loose or the wiring broken or if the switch is goosed . I believe there is some information on the forum in the 'How to ' section .
John .

Hi. Thanks for the reply, I have checked this water temp sendor on T4, and it's giving correct values.

There are two switches, I believe one is blue in colour and the other is brown .

T4 is showing that both of these sensors are giving out the same values.

Have you checked the readings from the thermistor when the engine is warm ? Other things to check are basic really, like the air filter and it's intake tube blocked , plugs are often ignored and the coil packs and leads . You say you have checked the O2 sensor but I'm pretty certain the TF has two , one upstream and one down . I have heard of voltage leaking from the heating side of the sensors which if so causes the ecu problems . A healthy O2 should give a voltage if my memory serves me between 0.8 - 1.2 volts and this switches very quickly about two three times a second . It's not possible for a healthy Lambda to produce a voltage above say 1.5 volts . If you see voltages like that then there are issues within the sensor ,ie leaking from the heating side .

Thanks for getting back.
I changed the lambda. Didn't change the second one because T4 is showing correct readings. I got the T4 after changing the first lambda.
All readings on T4 are spot on. From cold start right up to the fans coming on.
I'm in France and use E10 petrol.
I also have a ZR 120 that is showing similar signs.
I'm wondering if I might have an injector problem. I heard that ethanol attacks plastic injectors.
Plugs, leads and coil packs are new.

Well if you find out it is E10 that's causing the fault it doesn't bode well for us in the UK as I believe that E10 will be with us in the new year . There was a post on the Tbar recently where somebody spoke to an Ex Rover engineer who said that all vehicles built by MG Rover from 1996 were all E10 compliant . :yesnod: :yesnod: Keep us informed as to what you find .

Regards John

Ps Where did you manage to get a T4 from ?

I got the T4 from my local ex MG Rover garage. They had 2, this one didn't work. I had to sent it to the UK to be fixed by a genius on the rover 75 forum.