Looks like the problem was a crankshaft sensor... AND the fuel pump.

Thanks for the help.

Thanks Bill!!!

Would appreciate some help finding a fuel return line (about 3' long, the one that connects to the filter). Used would be preferable to paying $270.00 new. Any suggestions? TIA, Dave

Hi Bill, & everyone...

Well, replaced the O2 sensor...

No joy. Same behavior as before.

About ready to part it out of it's misery.

bump

This sounds exactly like the problem I have...

"[Diagnosis 6:] Oxygen Sensor malfunction. If the engine bogs and will not rev, with a very slight hint of backfire/misfire, while accelerating from a dead stop; or cracks, once in a while, like it is backfiring through the intake, then check the ...

Hi Jerry,

Tested both sensors, both appear to be operating normally. Vacuum line to pressure sensor seems OK.

It did not throw a 1-2-1 code when I checked the OBD with the pressure sensor connector disconnected. Car died when I pulled the vacuum line to the pressure sensor.

One other note: If I ...

Sorry, forgot to mention that (unless I missed one, but I took care to be thorough) all vacuum hoses were attached, and appeared to be servicable.

Also, not wanting to get ahead of you, but is this the sensor in question?

http://www.volvoclub.org.uk/faq/EngineSensors.html ...

Hi Jerry,

Thanks, at least now I know a bit more about this wagon.

On the brace to the spring tower there is a doo-dad which has a white semi-opaque hard plastic vacuum line going into it and also a 4 wire flat electrical connector (upper right corner of the picture I took, unit has a gray metal ...

Thanks, I'm really glad I found this site, and many thanks for offering to help! (I hope) you're gonna love this...


My engine appears not to have a MAF(!).

http://i29.photobucket.com/albums/c264/dnarby/1991%20Volvo%20740/Volvoenginepix003.jpg


It does have an Air Charge Temperature Sensor ...