Excellent news,

The problem was the oxygen sensor. At idle with a warm engine it would stay at 0.2volt maximum, sometime it would stick a while at 0.08volt. That is measured on the green wire/sensor connection. I left the wires connected to the ECU, only slided the rubber cover to hookup the voltmeter. The digital voltmeter has an input impedance of 10 MegaOhm.

Last friday I took the sensor out for cleaning. I blew compressed air, soaked in lacquer thinner and more compressed air.

After this medecine I took the car for a ride. I did not show any improvement

Saturday morning my younger son was getting married. I was to take him to the ceremonial with the beautifull 1991 (75k km). With my wife we decided it was not the time to get stranded on the way to Montreal. So we took the 1982DL, it is classified as antique car this year. After all we had a good laugh about this; is it not popular to use an antique car at weddings?

This morning I changed the fuel pressure regulator and took a ride(no change). Then I did put on a used oxygen sensor (13034) and I saw right away how it should alternate every one or two seconds. This one goes from 0.06 - 0.08 volts to 0.71 - 0.75 volts. I dont know if it should be closer to 0.2 to 0.5 volts as mentioned but the engine runs much better.

I will buy a new sensor when I get a good price.

I thank all the peoples that took the time to show me the right direction. If I can I will share my experience also.

Looking at your test of the O2 sensor, it is putting out voltage, just not what is normal. That may not be a fault of the sensor but a symptom and the sensor is working and is reacting to some other problem. The sensor not reacting within a narrow range out of normal is probably what set the two codes not the cause.

I cannot find my book on injection, so at this time I am unable tell you if low O2 sensor output is reaction to a lean or rich mixture.

Lean mixture: Air leaks. Ends of hoses; intake gasket; injector seals; bottom of tube or in between the folds of the AMM to throttle body hose; charcoal cannister and hoses; clogged fuel filter; bad FPR; stuck backcheck valve in the fuel line. Probably a few more that I've forgot.

Rich mixture: Bad ECU temp sensor; bad FRR; leaking injectors; leaking cold start injector andf a few more I've forgot.

Also, remove, clean and replace the ECU grounds on the intake manifold, and negative battery to block connection. A poor connection there can fool the ECU into thinking something is wrong when there is nothing.

Duane

"I did read somewhere that it should alternate between 0.2 and 0.5 volt every 3 seconds.
Is it what the voltage should be?"

I'd say that a good sensor on a warm engine should cycle between 0.2 and 0.7 volts, and be almost faster than you can read on the meter. Ideally most of the time above the 2s and below the 7s, maybe a stray 0.8V now and then.

I don't know of anyone who ever found a bad/marginal AMM from those resistance checks.

The only AMM meter test I know is to peel the harness plug boot back so you can probe the output wire (pin 3, white/red wire) for at least 1.2V to 1/3V with key on. With AMM detached from ducting for access, fanning air in with your hand will raise the test voltage noticeably (no spec that I know of).
TIP: Make an AMM test plug from a junk yard harness section so you can jumper +12V to pin 5 (orange), ground pin 1 (black) and then test pin 3 (W/R).

I have one LH2.2 AMM that tests 1.2V. It starts OK then stalls right out. I may try CRC's new spray can "AMM Cleaner" on it just to see if it responds to snake oil.
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Bruce Young
'93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

Check your fuel pressure regulator.... also, did you swap AMM's or just do comparative tests on the three? AMM's for later 240's are incredible black boxes... and I know of no definitive test.

-Ryan
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Athens, Ohio
1990 245 DL 133k M47, Cibié E-codes
1991 745 GL 290k (Girlfriend-mobile)
Buckeye Volvo Club

Not sure about your codes, but the O2 sensor should be cycling to a much higher voltage, like 0.5. And yes, a digital voltmeter is the right tool for the job, although you need to confirm it has several megohms of input impedance.

Read up on O2 sensors in the 700/900 FAQ section - http://www.brickboard.com/FAQ/700-900/EngineSensors.htm#OxygenSensorLifeandDiagnostics
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Thank goodness we don't get all the government we pay for. -- Will Rogers