I've owned my Volvo 850 2.5 10V 1995 Estate for 18 months now, 212,000 Miles on the clock (203000 when I bought it) It's got the dreaded RMS oil leak which I was about to do myself (when brave enough) but now I have a more immediate problem, it won't start.....

I've had intermittent starting since I got it, the engine will sometimes start then die after about 3 seconds, even though it sounded right (no misfires or tapping etc) it was clearly an engine management shutdown, so I looked it up on sites such as Volvospeed and took the advice.

I cleaned the Flame-trap and Throttle body and changed the Oil to GTX HM and filters etc. it "seemed" to help, but got sporadic episodes, where it would take 2-5 attempts to start and continue running, there was no apparent reason, as it happened when the engine was hot or cold and sometimes didn't happen at all for weeks...

BUT.. three days ago it took about 20 tries to start up when cold, then was OK for the rest of the day, the day after, it refused to run for more than 3 seconds and has refused since.

I have spent time and money in the last couple of days, I checked the Spark Plugs (like new with no oily/bad deposits) and cleaned them... The distrubutor cap was well coked and pitted so cleaned that but it still looked bad, so I replaced it, to no avail. I cleaned the Flame-trap yet again, but it still refuses to play ball.

My local mechanic (too busy to look at my car for 2 weeks) advised it's probably the Crank Position Sensor, so I bought one from a Genuine Volvo Dealership for £40+vat, but it didn't make any difference. I also checked all the visible wiring and connectors to sensors and fuses thereof and the main relay etc.

I obviously needed to get the OBD2 fault codes (I have the connector on the centre console) but I didn't have theOBD2 reader and wasn't going to waste £25 or more getting it done at a local garage. (I could buy one for £39) So I made my own reader... with some great help from the internet, and am now the proud owner of a reader and these 2 codes.

121 and 122 Which apparently mean

1-2-1 Manifold Absolute Pressure (MAP) signal absent or faulty
1-2-2 Air Temperature sensor signal absent or faulty

Where are these sensors, and are these codes relevant to the problems I am having?

I hope someone can help, I'm tearing my hair out and having to drive a hired car "yeachh spit. spit" compared to a Volvo 850, it's a tin can.

Please help me before I go bald

Thank you in advance!

David