Running Rich?

[Eldavo]

Took my car to the auto electricians this afternoon to drop it off as they are going to code some new key fobs to my alarm tomorrow. My friend followed me to give me a lift home and had his window open, he remarked that there was a strong smell of petrol coming from the exhaust as I pulled away at each junction and this tallies with my own suspicions too.

Once or twice, after some slow progress when I get the chance to then open her up i've got a pop from the exhaust and I can only assume it is unburnt fuel that has loaded up and burnt off with the exhaust gases, again this makes me think it may be running rich.

Emissions were ok at the MOT, is this due to lack of use of should I crack the multimeter out and start testing sensors? Any ideas gratefully received, thanks.

 

[robwright]

Unusual for a NA to pop a fart like that. I would start with the air flow meter mate. Due to it's "barn door" mechanical nature it can quite often be the culprit.

 

[Alexw]

its one of those problems that could be many things, off hand I think
FPR can cause it, you test that I beleive by popping off the vacuum line to it while running and see if fuel comes out? Or is that on a turbo?
DME Engine temp sensor - easy to check with clarkes guide and a multimeter,
then theres sticking injectors, the AFM.
All I can remember at this hour.
Could be due to lack of use, mine can get cranky when left for a while....
I'm yet to see a regular culprit for this problem, has anyone else?

 

[Northern924]

There's not really anything you can adjust on the '44 as its all controlled by the ECU, I seem to remember you saying you'd just done a servie fo the usual stuff when I last saw you.
Check the air flow meter head, they do start to leak and as such draw more air and as a result more fuel.
But if you haven't used the car much it is going to smell a bit, the Mrs was behind me coming back from the garage the other day and said it stank, but then she always says that.
If you can run it as your daily for a week do, and see what its like after that.

 

[alwigley]

DME temp sensor could easily be kidding the DME into thinking it is colder than actual temperature, and therefore running rich as a result - this sensor is pretty key to the whole DME system, and although it is supposed to be easy to test with a multimeter, they can fail slowly/intermittently and be tricky to diagnose - £15 part that is easy to replace......... spent weeks trying to figure out faults on mine including running rich, all down to this sensor.

Agree with the other that the AFM could also be the culprit, although sounds more like a mechanical (ie dirt clogging the AFM) problem than an actual fault with the AFM itself.

Happy hunting []

 

[robwright]

Yes agree after th AFM I would be looking at the DME coolant switch and sender. In other words the temp sensor on the block with the blue top. This can be quite problematic. So much to say I shall change mine this autumn before I do my coolant change or winter. The resistance can read OK but it is possible there could be crud etc on the outside of the sensor surface. A nice cheap one if that's what it is.