So, I recently purchased a 1991 740 Turbo with 165k. The car needs a little TLC but for the most part has a lot of life left in it. A strange thing I am noticing, is that I can always start the car up. Sometimes there is a screeching noise, sometimes not. When there is a screeching, and even a few times when there was not, it seems that I do not have any power to certain units in the car such as I cannot put the shifter in gear (auto), the a/c does not work, headlights do not work in third position. The car is running, I can use the accelerator to rev the engine, but cannot shift the car into gear.

Sometimes I'll just turn the car off and restard it and everything works perfectly. The screeching noise makes me believe it's not a fuse or anything, perhaps alternator? Also, the car has stalled once or twice while driving within a few minutes of having started it up.

Any suggestions, insight would be much appreciated.

Thanks,
Bill

 

Check your belts, battery and starter...not nessessarily in that order though

 

Either Alt. or maybe even the electrical part of the igntion switch.

 

i was thinking alternator... because of the screeching noise.... when i start the car, it sometimes will let me put on the headlights, shift into gear, etc., sometimes not... next time i hear the screeching, i'll open the hood and give you a better description...

 

One more thing to check.
Mark the Crank pulley from inner edge to outer edge.
Then start it up and listen for the noise. If you hear it let it run for a second then turn it off and see if the marks still line up.
The pulley might be bad and spinning.

 

Today, it happened again. I started the car, the engine seemed to be running fine, except none of of the electric accesories worked.. trans shifter, windows, a/c, etc. I opened the hood. The alternator belts seemed to be spinning fine, by the time I got back to the driver's seat, the car had stalled. I restarted, and everything was fully functional. Oh, there was no screeching noise either.

I'll try marking the crank pulley tech

 

The car is stalling while driving now

 

Any codes on the system?

 

what do you mean by codes tech?

 

did a little research and i'm assuming you mean the codes listed at this page:

http://www.troublecodes.net/Volvo/

the car's at the mechanic being diagnosed. haven't heard anything back from him, but maybe i'll take a trip there and check the codes. is it easy to do? i'm not extremely mechanically knowledgeble

 

Yes it is easy read through the Page you linked and learn how to pull them.

 

okay... got the car back from the mechanic... who couldn't figure out was wrong (the check engine light only goes on after it stalls the first time, and i guess he couldnt get it to stall). I used some ATP fuel treatment to make sure there was no water in the tank, but it stalled out on me twice last night. The dealer mentioned when i bought it that it may need an O2 sensor. Could that cause the car to stall? Or was he simply making up a reason for the check engine light to be on?

 

The O2 sensor won't really make is stall.

If you can get it to stall again read codes after it stalls before trying to start it again.

If it stalls try to leave it and coast into a parking lot and pull codes.

 

thats what i'm going to do. the check engine seems to be on when you start the car now. so i'll try to check the codes tomorrow. I just drove it home about 45 miles and it worked perfectly, but the check engine light was on. does anyone have a picture of where the diagnostic unit is located?

 

On your car it should be on the left side strut tower.

 

Alright, I was able to check the codes while the check engine light was on. Here are the results:

Selector cable in socket #2: 2-3-1
Selector cable in socket #6: 1-4-4

Any suggestions? The check engine light seems to be on at all times now.

 

2-3-1 = Lambdfa adjustment. wtf does that even mean? 1-4-4 = Fuel system load signal(missing or defective). I get this code when ever my lead foot gets to heavy on the gas.

 

yeah, i'm not quite too sure what lambfda adjustments are, either. But the fuel system load signal missing or defective makes sense because it mentions the car will stall, which it's doing.

 

There are a couple posts on turbobricks that call it out as a vaccumn leak or bad vaccumn seal somewheres or even a bad FPR. Hears a good one to check out

 

144 is a communication problem between the engine control module and Ignition control module.
231 is a vaccum leak. But alot of times on the 4 cylinder it comes up when no leaks are found.