Hello friends. Had to drive to the big city yesterday evening. A 45 minute drive at highway speeds until lots of lights with stops and starts. My car decided to start hesitating and finally died and I was lucky to get into a parking lot. After 30 seconds it started fine and I drove another couple of miles and it began to stall at lights again. It finally stalled again one minute from my destination and I had to walk to my meeting. This did not happen the first 30 minutes of highway driving. Seemed fine! Four hours later I went back to my car and it started fine and it made it home fine but I was nervous the whole time. The gas was fine, the oil was fine, the tranny fluid is fine. My mileage is a bit less and the check engine light is on and also the service light. What should be my next logical steps? vvheader

Read the codes first. Ignore the service light, it goes out after 2 minutes anyway. Or clear it using port A-7 and 4,1,5,1.

If your codes indicate a misfire or an O2 sensor, start looking for a cracked vacuum hose.

Klaus

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Praying for Cynthia Amendt, heaven bound

Hello Klaus. I was hoping you would weigh in. I pulled the codes three separate times to be sure and the codes were: 121 - Mass Air Flow sensor signal, 232 - Long Term Fuel Trim - Idling, and 231 - Long Term Fuel Trim - partial load. I am not sure exactly what they mean. The MAF sensor looks like a junk yard replacement part that someone put on the car before I got it. It has those marker numbers that u-pull-it yards use. I am thinking that possibly I may need the oxy sensors also. Just a guess. Perhaps the MAF is the main culprit and I affecting the oxy sensors? Someone else said to test the coil. Also I am not sure I understood how to get the service light off as per your instructions. Thanks for any help!!! -- john

MAF is your #1 culprit, either clean it or replace it. Once the MAF works, start looking for non-metered air entering the intake manifold. Usually from cracked vacuum elbows.

The service light:

Plug the prob into A-7.
Hit the black button 4 times.
After you get a glowing red light, hit the black button again.
Glowing light, hit it 5 times.
Then once more for good measure :)

Klaus
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Praying for Cynthia Amendt, heaven bound

Klaus, I put a brand new MAF in and new plugs and removed the codes. Car did fine for 3 weeks but I am now getting the 2-3-2 code again and the exhaust smells rich again. The check engine light is off and on again like before. I am worried about things getting worse again and I get stalled. What is the culprit? I cleaned the MAF sensor plug. All the hoses seem good. The only thing I suspect has not been changed in a few years on this car is the 2 oxy sensors. Could they be the problem and if so, why? What do you suggest? ~ JG

The 2-3-2 is caused by air getting into the intake manifold. If you have a turbo, the usual culprit is the vacuum line coming from the #1 cyl area. If you have an NA, check the vacuum tree and all of the lines next to the throttle body.

There is a vacuum line from the fuel pressure regulator to the vacuum tree, if it has fuel in it, the FPR is probably leaking a little.

If there is a suspected leak, you can spray TB cleaner on the line and see if the idle changes slightly. Try this on the intake manifold gasket as well.

Klaus
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Praying for Cynthia Amendt, heaven bound

This is not a turbo, but a basic NA. I will look again. Thanks.

If you haven't had the battery disconnected since replacing the MAF, you might want to review this thread concerning resetting the LTFT table. If it isn't reset (clearing the codes won't do it), you might still be getting problems from that even if everything else is just fine now.

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'96 850 and '83 244 DL both at about 200K; gone but not forgotten '81 245 and '64 Amazon

Should I turn the key to ON after disconnecting the battery and then turn it off after RECONNECTING the battery? Kind of confused on that.
JOhn

You definitely would not want to reconnect the battery with the key in the ignition at all ... I think the part about turning the ignition on AFTER disconnecting the battery is just to be sure any residual charge in the system is drained. Probably not necessary if the battery is disconnected for ten minutes as he recommends. But turning the ignition on BRIEFLY with the battery disconnected is guaranteed to drain any charge!

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'96 850 and '83 244 DL both at about 200K; gone but not forgotten '81 245 and '64 Amazon

Hi,


I was reading the Volvo service manual last week.

It said that an air box thermostat was included on non turbo models.

Please check that the air preheating system is not incinerating the AMM.


Goatman

Should be disconnected on all of the 850s. At least, the flap should be closed at all times. The engines will run just fine, even in Fargo ND.

Klaus
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Praying for Cynthia Amendt, heaven bound

Hey, I was wondering about that. I have disconnected that on all my 240s and closed off that port (basically gutted it, stuck a rag in it, AND duct taped it over and threw away the aluminum piping. Thanks Klaus and Goatman. Will do that also.

John

Hi, I would test the coil.