Hi Uncle The Rod,

Two tablespoons of water? Very unlikely. The ethanol in Summer fuel mixture may suck up that water. Most (or all?) alcohols are anhydrous and absorb water brake fluid of the ethanol in your Summertime fuel mix. You can buy fuel additives that perform this water-absorbing duty so any water in the fuel passes out through engine combustion.

I imagine you smell the exhaust when your 940 is fully heated up (engine and exhaust) and no steam appears at the tail pipe. The exhaust should be clear, pretty hot, is dry, and have a somewhat sweet smell.

http://www.brickboard.com/FAQ/700-900/EngineOBDCodes.htm

So, you checked for codes in socket 2, the Bosch LH-Jetronic system. Did you repeat the process to verify you've encountered all fault codes? You should also test the Bosch EZK ignition system using socket six and the same procedure. A fault in one may mean a fault in another.

The Lambda trim is a fine tuning of fuel to air ratio as you drive your 900 series. The trim control engages at the late part of the warm-up cycle.

In the 700/900 FAQ (http://www.brickboard.com/FAQ/700-900/), you may find information on how to test the 02 sensor. Please use the brickboard search function to search for threads containing a RWD Volvo oxygen sensor test (with voltmeter).

Oxygen Sensor Replacement List
http://www.brickboard.com/FAQ/700-900/EngineSensorOxygenReplacements.htm

I'll guess the fuel trim fails on the lean side from your description. I'm not sure. You could take your 1992 940 to an auto emissions station or someplace with an accurate exhaust gas analyzer. If HC (hydrocarbons) is low and NoX (nitrogen oxides) are high, you have a lean running condition. Depending on how lean, you may want to diagnose and remedy the cause so your catalytic converter does not suffer. The catalytic converter on any so-equipped automobile suffers and can prematurely fail if the exhaust gases are too rich or too lean.

Also, a lean running condition cause valve knock (precognition). The ignition system knock sensor, if it works, can pick up the pre-ignition valve knock and adjust timing. If you do not have valve knock under hard acceleration, the fault causing the condition, if lean, may not be so bad, yet must be corrected.

If your 02 sensor appears fine, other causes can include:
- Air intake leaks after the MAF/AMM sensors.
- ECU temp sensor may be faulty. (I think as these fail, the fuel mixture goes rich. Research to verify.
- Clogged main fuel filter.
- Poor fuel delivery from the priming in-tank fuel pump to the main fuel pump.
- Ignition timing is off. (I forget of advanced or retarded timing causes lean combustion.)
- Valve timing is off. Perhaps the timing belt is loose and skipped a tooth?
- Spark plugs are too hot.
- If you have an exhaust leak high up on any of the cylinder head to exhaust manifold gasket or the exhaust manifold to head pipe gasket, that appears to the Bosch LH-jet as lean-causing exhaust gas condition. If you have an exhaust leak at the union between the head pipe output to the catalytic converter input, this appears to the LH-Jet at the 02 sensor as a condition to go rich as the extra oxygen sucked into this exhaust leak between exhaust pulses.


The measure is between the AMM/MAF air mass measured versus what the exhaust gasses contain. So, something is wonky that the Bosch LH Jet sets a code 1-1-3.

Others will have better ideas.

Questions and comments?

cheers,

Buttermilk.