Chim 4.0 Running VERY Rich

[rosshand]

Help!
My Chim has been running rich for a while now i belive,
the symptom is that pure carbon is being splattered out of the exhaust. we have changed plugs, oil+filter
It has got worse recently, and is now leaving marks aroung the rear lights and number plate after a good run on the motorway.

Please help!

[GreenV8S]

rosshand said:

Help!
My Chim has been running rich for a while now i belive,
the symptom is that pure carbon is being splattered out of the exhaust. we have changed plugs, oil+filter
It has got worse recently, and is now leaving marks aroung the rear lights and number plate after a good run on the motorway.

Please help!

I'd say there is something wrong, if I had to guess then the coolant temp sender would be the first thing to check, but unless you guess lucky you will need an expert to go through it systematically.

[rosshand]

Thanks for the reply, what are all the options of wrongness?
Engine seems to be keeping its self cool ok.

[Colin L]

Check out the air flow meter, all the wires are correctly connected. If its not connected the car will run, but run very rich.

Colin L

[rosshand]

Thanks Colin I will give that a go
Is there anyway of testing to see if the airflow meter is actually working?

[mdotrutherford]

rosshand said:

Thanks for the reply, what are all the options of wrongness?
Engine seems to be keeping its self cool ok.

Thats not related to temp gauge, its a separate sensor to the ECU so it schedules the
correct fuel delivery. ie if sensor fails ecu thinks it is in cold start mode
and will not know any different.

[tinker-27]

check the vac pipe that goes from the back of the plenum (next to the stepper motor) to the fuel pressure regulator if this has a leak it will raise the fuel presure and go rich ,the tube tends to perish

[jsr]

rosshand said:

Help!
My Chim has been running rich for a while now i belive,
the symptom is that pure carbon is being splattered out of the exhaust. we have changed plugs, oil+filter
It has got worse recently, and is now leaving marks aroung the rear lights and number plate after a good run on the motorway.

Please help!

Possibly lambda sensor failure? Might be worth checking the ECU for any fault codes, if you can get access to a code reader.

My 400 was running very rich last year when both sensors failed. MPG went down to about 13mpg. Suspected lambda sensors so ordered a pair. Before they arrived, i bought a fault code reader which confirm they had failed. Everything is fine now.

Would suggest getting codes checked first though, as the sensors are expensive.

[Tobs]

I had a similar problem and found that my afm was full of water! Dried it out and all was OK. I eventually replaced it with another from e-bay. Check the voltages from the AFM or swap it out with a known good one if you can.

[-JUT-]

mdotrutherford said:

rosshand said:

Thanks for the reply, what are all the options of wrongness?
Engine seems to be keeping its self cool ok.

Thats not related to temp gauge, its a separate sensor to the ECU so it schedules the
correct fuel delivery. ie if sensor fails ecu thinks it is in cold start mode
and will not know any different.

Had a badly corroded one of these on mine that affected how rich the car ran. Not an expensive part and also pretty quick and easy to change. As said above, the sensor only affects fuelling not engine temp, so a defective sensor won't manifest itself in hot running, it'll just cause your engine to go into cold-start mode as a safety measure and overfuel.

[rosshand]

-JUT- said:

mdotrutherford said:

rosshand said:

Thanks for the reply, what are all the options of wrongness?
Engine seems to be keeping its self cool ok.

Thats not related to temp gauge, its a separate sensor to the ECU so it schedules the
correct fuel delivery. ie if sensor fails ecu thinks it is in cold start mode
and will not know any different.

Had a badly corroded one of these on mine that affected how rich the car ran. Not an expensive part and also pretty quick and easy to change. As said above, the sensor only affects fuelling not engine temp, so a defective sensor won't manifest itself in hot running, it'll just cause your engine to go into cold-start mode as a safety measure and overfuel.

Thanks!
Will definatly try removing the sensor, is that the sensor in the side of the exhaust downpipes?

[mdotrutherford]

No mate think your looking at the lambda or O2 sensors there, theres one each side.
IIRC the ECU temp sensor is 12'o'clock next to the analogue temp gauge sender from
previous Rover models, sorry dont have my Bible to hand to confirm.
Do a search of Chim/Griff forums for more info/location.
Hope this helps
Ian

[nicktowe]

I had the same problem, and it turned out that the airflow meter multiplug had come off

[-JUT-]

rosshand said:

-JUT- said:

mdotrutherford said:

rosshand said:

Thanks for the reply, what are all the options of wrongness?
Engine seems to be keeping its self cool ok.

Thats not related to temp gauge, its a separate sensor to the ECU so it schedules the
correct fuel delivery. ie if sensor fails ecu thinks it is in cold start mode
and will not know any different.

Had a badly corroded one of these on mine that affected how rich the car ran. Not an expensive part and also pretty quick and easy to change. As said above, the sensor only affects fuelling not engine temp, so a defective sensor won't manifest itself in hot running, it'll just cause your engine to go into cold-start mode as a safety measure and overfuel.

Thanks!
Will definatly try removing the sensor, is that the sensor in the side of the exhaust downpipes?

As said above those are the lambda sensors and are around a ton each, don't want to change those unless you have to!

Difficult to describe exact location of the temp sensor, but I'll try.

Open the bonnet, stand on the passenger side of the car, and look down on the engine from above. The temp sensor is near the centre of the engine, and roughly speaking, if it were located on the driver's side, it'd be near enough under the ignition coil - so look around this sort of area, but on the passenger side, if you get my drift... the sensor has a plastic spring-clip plug on it, and once this is off, it unscrews with a socket (19mm if memory serves me) and lifts out vertically. You might lose a bit of coolant as it comes out, but not very much when I changed mine.

[GreenV8S]

If you wait long enough, you'll end up with a fairly comprehensive list of all the things that could go wrong with your engine management system and all the things you might need to replace to fix it. However, you'll be no closer to knowing what's wrong. Unless you are able to diagnose the problem I'd question whether you should be trying to solve it. You are in danger of replacing a lot of parts in order to locate it by trial and error, you stand a chance of breaking something else along the way and you could waste a lot of time and money. Unless you already know what you're doing, or understand the basic principles of your engine management system and don't mind learning as you go (and all the risks that entails), my advice is to get it fixed by an expert.

[spend]

Or you could buy a LandRover as a second car, that way you have lots of bits to try swapping

Dave

Sounds silly but it might be cheeper than buying all the possible bits that talk to your ECU...