My 240 has not started in a couple of months. Based on some of the posts on this site, I am thinking that it may be the crankshaft position sensor (RPM). I also plan to replace the fuel relay and the power stage. I noticed that the wire going into the top of the RPM has the insulation coming off and the wiring is exposed which leads me even more to consider that it is the RPM.

Is there a simple way to remove the old one? Are there any things that I need to remove or can remove first that will make it easier to get to the RPM? Exactly where in the firewall does the other end of this thing connect? Can someone tell me exactly what tools they used to remove this well hidden item? Thanks everyone.

Just wondering if you had checked the fuel and spark before coming to this conclusion. I understand frayed wires but that is really a normal in some of these bricks. A lot of posts talk about the wires being frayed but posing no problem. I have two vehicles that have the blue foil showing and have been that way well over 5 years so far. Not saying the sensor is not your problem just wondering if other things might as well be causing it not to start..
--
Max..1989 244 DL 5 Spd., V15 Phase II Cam Bilstein HD, Turbo Swaybars, Poly Bushings all round, Turbo Wheels, Black leather interior, Electric mirrors, LED dash and gauge lights and now NEW ECODES with the turn signals, 1992 black 244 next project

I have had bad Crank Position sensors with bad wires that would respond to moving the wire around. Apparently that would either connect wires that hadn't been touching or, more likely, separate wires that should not have been. This isn't any kind of solution to the problem, of course, but it might get your car started once or twice so you can move it.
--
Andy in St. Paul - '91 745 227K mi, '91 745 210K, '90 744 194K, all Rex-Regina; '86 745 GLE M46 230K; past 240s

I recommend removing it from the top. I use a 1/4" drive, 10mm wobble socket and a 12" extension. Be extra careful when pulling the sensor from it's mounting bracket. Don't break it. If you do it will cause you a major pain in the a**. You might want to spray it with penetrating oil the day before.
hope this helps
steve

I'm going to 2nd this motion. I can't envision how getting at this from under the car is easier. I've never had one stuck either.

After doing this job myself on several 740's (easy!) and my 240, here's what works best for me on the 240. (I do have long skinny arms!)

Engine cold, hood up. Stand on the passenger side. Lean in and put your right forearm on (and parallel with) the cylinder head. With a wrench* in your left hand, bring your left arm in low and behind the engine. Loosen and remove the bolt holding the sensor in place. Put the bolt somewhere safe (not in your hand). Now remove the old sensor. Hopefully it's not stuck, but again, it seems to be the exception not the rule to have one stuck.

Once the old one is out, seat the new one in its place. Now get the bolt, put it part way in the hole of the sensor, and the rotate the sensor until you can feel the bolt line up with its threaded hole, start threading it, then snug it up with the wrench. Just be careful to not have the bolt in hand when the sensor is not in is place: if you drop it into sensor's hole and into the transmission's bellhousing, life will be bad... very bad.

Plug the sensor's connector in, and you should be good to go.

*I'd reccommend using a 10mm GearWrench brand gear wrench with the flexible head. Nice, fine ratchet, and available $10 individually from Lowe's.... though, probably worth getting the whole assortment. I wish I had a set of these when I did the OD solenoid on the 740.

FYI, a 1/4" Craftsman brand ratchet can just barely go one click between cylinder head and firewall on the 240.

Good luck!
-Ryan
--
--------------------------
Athens, Ohio
1990 245 DL 130k M47, E-codes
1991 745 GL 280k (Girlfriend-mobile)
Buckeye Volvo Club

If the insulation looks frayed, absolutely replace it now, even if it is not the cause of your current no start (though it may well be, yours is overdue for replacement).

My car was a'91 with a 5-sp manual. I put the car on ramps reached around the transmission with a 10 mm wrench, and mine came right out. Others go down from the passenger side with a very long extension with a bit of a wobble on the end. Small hands and thin arms are a big plus for this job.

Some report a lot of difficulty pulling the old sensor out of the hole. Work it out carefully and don't break it off!!!. Don't drop the bolt or anything else in that hole!!

Thanks for the advice. I had thought about the possibilty of trying to access this from below the transmission as you did. It is encouraging to know that you were able to do it this way. How did you get your car up on the ramps mine won't start?

Excellent question. I didn't think it through that far.

When mine failed, the wires were actually shorting to the block. I slid a split plastic wiring harness sleve down the wire to shield it, and the car started and got me home (200 miles) so I was able to drive up on ramps. Try just giggling the wire a little to move it and see if the car will start.

Hey thanks for the suggestion. I moved the wire of the rpm a little as you said and was able to start and restart my car several times. I know that this is not a long term solution and I would not want to run the risk of an engine dying on me in the middle of the freeway, but I now know that this is really one of my overall problems. I will order a new one from FP Groton and face the music of taking off the old one and putting on the new. Thanks again.

"How did you get your car up on the ramps mine won't start?"..........Good question. Jack up the front, sit it on jackstands....high enough for you to crawl under. Just make sure it is solid on the jackstands.
--
84, 242GLTi, 167K, 4+OD, not on the road yet; 89, 245 DL, 340K, M 47, daily driver; 93, 245, auto, 167K; daughters 84, 242 Ti, 193K ; and other toys.