TS engine running rich

[GTVeloce]

Finally replaced the coolant temp sender to the ECU...and it made no difference. However, I did notice the wiring to the AFM is feeling a little hard so next step is to check resistance between the connector and the ECU plug and then see what readings I get when it is running. I'm tempted to get a pot and put it in line with the signal wires to the ECU for the CTS and AFM and see if I can 'fix' the problem by changing the reading the ECU sees. At least it would tell me if I'm on the right path.

It's frustrating because I just want to finish this and move onto the next thing to work on, replacing the clutch!

[Citroënbender]

Has this got one of the old school Bosch airflow meters? There's a fairly interesting article on the net by a bloke going over one from a BMW bike (I think), he discusses the precision they were made with. Also he shows his careful relocation of the resistive tracks and testing setup. If nothing else it gives appreciation of how a hamfisted approach to tinkering with one, can really mess things up.

http://www.k100-forum.com/t11055-bosch-air-flow-meter-restoration-summary

[Henry Goodman]

Out of interest what spark plugs and heat range are you running? Would it be worth considering a warmer plug?

Henry.

[GTVeloce]

Have already tried the warmer plugs but no difference. I have traditionally used Bosch FR5DC plugs and they run well but Bosch actually recommends the FR6DC so I have a full set of those that are fairly new. Didn't seem to make any difference and inspecting them they appear to be about correct.

That said, If I was buying another set I'd go the FR5DC as I never had a problem with them even on cold mornings.

I tested the wires going to the AFM today. Given the wire length (both from sensor to ECU and for testing) the readings seemed ok. I was getting 0.3, 0.4 or 0.5 ohms on every wire. Someone correct me if I'm wrong but I would think that should be fine and unlikely to cause significant problems. Next test will be voltage at the plug while the engine is running to see if load makes a difference.

After that, I am starting to get stumped. I would like to try the same thing with the CTS but not sure I can get access to that while having the engine running.

There is a small leak in the exhaust near where the O2 sensor is but again, I believe that shouldn't affect anything given I am running open loop at the moment. I disconnected the O2 sensor to double check and it made no difference as expected.

[Storm_X]

Personally I would try mixing some e85 into your tank (if application is compatible) and see if it runs any better.