|
|
|
I got myself into a pickle. I'm working on my 89 780 with a 4 cyl turbo motor. I had the motor completely out for some work, and on reinstalling the motor, I cannot seem to locate the wire harness for the crankshaft position sensor. The sensor itself is on the passenger side near the oil pan level, not on the top of the bell housing like the newer ignition system.
From the pictures I took (to try and avoid situations like this), the sensor plug is mounted to the rear passenger corner of the valve cover. The plug is 4 pin with three wires.
I have no loose wire harnesses and for the life of me I cannot find where the sensor plugs into.
Coincidentally, the engine will not even crank. I'm not sure if it's related, and I'm still investigating the no crank problem.
If you have a similar set up on your vehicle, I would appreciate pictures or a description of what the sensor plugs into and color of the wires. Many thanks!
--
94 940 owned 20+ yrs, 330k+ miles; 93 940; 89 780; 05 XC90 for the wife; 07 S60 for the daughter. Sold 88 760 and 92 745T.
|
|
-
|
|
|
In the 740s, the turbos were still LH 2.2 in 1989, while the NA engines became LH 2.4. Odds are that Art's suspicions are right and your 780 B230FT doesn't have a CPS. Something electrical on the passenger side above the oil pan strikes me as possibly being the O2 sensor on the exhaust downpipe.
--
Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now
|
|
-
|
|
I know it is a real tiny and poor illustration, but the sensor for the Monotester screws into a threaded hole in the block in front of the flywheel/flexplate and its electrical cable is two conductor plus shield leading to a 4-contact socket attached by one of the cam cover fasteners. With your experience, Dave, you just need to visualize it to remember it.
--
Art Benstein near Baltimore
How do you get a person to read a book on reverse psychology?
By telling them not to read it.
|
|
-
|
|
|
Art, that sensor in the bell housing isn't ringing any bells other than the Monotester name I've probably seen in an old manual. Reading elsewhere on the UK Club site it seems 1984 may have been the last model year that the sensor was fitted on the 240s and earliest 740 years with the connector living on a bracket up above on the firewall. 1984 was the end of the K-Jet years, so that kind of suprises me we're talking about an '89 780 LH 2.2 here that has one. The first 240 I had intimate relations with was our '85 240 LH 2.2 B230F, so I don't have your 240 K-Jet experience. I don't recall anything magical about that area of the bell housing or a connector that I didn't know what it was for. Previously I was K-Jet on my '74 140 B20F so it appears I may have skipped over the Monotester years? Mind you, as long as I could figure out how to hook up a dwell-tach and adjust the valves I was good to go for most of the advanced maintenance I needed to do way back then. I'm wondering if the OP's 780 possibly has an older engine transplant. Also, the low production 780s did not come off the normal production lines, so there's another possibility.
--
Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now
|
|
-
|
|
|
"Art, that sensor in the bell housing isn't ringing any bells..."
It isn't in the bell housing, it is in the block casting. Perhaps that's why no bells are ringing.
Here's an old pic marked up to show where it is, even if the shape of it isn't that clear.
"1984 was the end of the K-Jet years, so that kind of suprises me we're talking about an '89 780 LH 2.2 here that has one."
This sensor provides the crank timing for spark. Fuel, whether carbs, k-jet, or LH has nothing to do with it. I'd guess the only place you'd have found a "Monotester" to connect to it in those days would have been a Volvo dealership service department. It would have helped with the ignition timing and dwell settings you and I use a timing light and tach/dwell meter to perform.
Here's another memory jogger.
The connector has a dummy plug in it to keep it clean. Cars that have survived to this era may have lost this decor.
--
Art Benstein near Baltimore
In 1980, the Winchester drive was born; based on a model from 1973. IBM introduced the 3340 "Winchester" disk system, the first to use a sealed head/disk assembly (HDA). Almost all modern disk drives now use this technology, and the term "Winchester" became a common description for all hard disks, though generally falling out of use. Project head designer/ lead designer Kenneth Haughton named it after the Winchester 30-30 rifle (initially called the "30-30" because of its two 30 MB spindles).
|
|
-
|
|
I am pleased report that my '80 242 retains both the monotester receptacle and it's dummy plug. Now if I only had a monotester. Oh, well...
And, on the subject of artifacts, it also still has external voltage regulator. How many can say that? Not that it's in service, though. It would probably still function if properly connected but was undoubtedly just left in place after being superseded at the time of an alternator replacement.
--
'79 242, '84 DL 2 door, '80 DL 2 door, '89 DL Wagon, '15 XC70 T6 AWD
|
|
-
|
|
|
Ah, now I see. I've definitely never run into one of those Monotestor ports. I'd almost certainly have remembered that tab on the valve cover nut as well as a mystery connector. Either that or I've had an unkown TIA in the Volvo Cortex portion of my brain.
Where the sensor is down behind the trans cooler lines is a bit out of sight, so if someone had hacked off the wire at the sensor that might not get noticed, but if I'd seen a cut wire I'd have investigated what it was for. I'm now vaguely recalling a square headed plug in the block back below the drain cock that I used to wonder about. I remember thinking it was some kind of extra drain plug or a freeze plug. I'm thinking my engines may have had a factory plug there.
I'm starting to wonder if it was market dependent whether or not there was a Monotester port.
For example, if dealer service in a country such as Canada, which was a sub-market and separate from Volvo North America with its own head office, plant and parts chain, then they may have saved a couple of bucks by not including the port and not needing to equip all the dealers with Monotestors which I'm sure were grossly expensive for what they were. We had dozens of small Volvo dealers scattered across the country until Volvo Canada did a major consolidation starting back in the late 1980s and closed all the smaller dealers. That's where many of our best indie shops came from as they had factory training plus old stock on parts shelves. Vancouver alone still has five Volvo dealers. There wasn't much extra it could tell an average mechanic, mostly just a convenience port.
Another possibility is it had something to do with the assembly plant whether you got one. Depending on the years and demand for a certain model or trim level, plus the availability of production parts, cars in Canada normally came out of the Halifax assembly plant with the engines shipped over in crates more or less ready to drop in with all the needed harnesses included. Cars destined for the US market often came from Sweden except only certain models and trims levels in certain years where Halifax had the needed production capacity. That sensor and port are a bit exposed for shipping and handling. Mine have all been Halifax cars right back to my '66 122S badged as the Sport Canadian model. Canadian models got what was called the winter package as standard. There were only a couple of years where both 240 and 740s came out of Halifax during what were called the production changeover years. For example, we might go through a period in the early '80s when all 240 DL wagons (which were in high demand) plus all the new 740s came from Sweden. Models like 780s (the OPs car) and the 262C Bertone Coupes always came from Sweden.
Those are my best guesses. Next time I'm in my Volvo indie yard I'll ask what they know about that sensor. In the meantime I'm sure they'll be a variety of comments here about people who have or not had that port.
And yes Art, I realize it has nothing to do with K-Jet/LH-Jet or the EZ ignition systems. It was just mention of 1984 on the UK Club site that made me wonder as introduction of the B230F with LH-Jet was about the only thing special about that year. I'll see if I can come up with some Volvo trivia to test you. Enough of these questions and we can make a Volvo Dementia Test for other old-timers to use.
--
Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now
|
|
-
|
|
|
Sounds to me like the connector for the magnetic timing sensor used on the early 80's 240 series (and I imagine 7 series too) for the Monotester, a proprietary instrument to set dwell angle and ignition timing. You sure your engine's ignition system takes its reference from the crank and not the distributor?
--
Art Benstein near Baltimore
"...some rust, yea they do that. " -Amazonphil
|
|
-
|
|
|
Thank you, Art. Late last night I read about the magnetic timing sensor and that it is a proprietary system. You are correct that I have a hall sensor inside the distributor. This is the first time I have spent intimate time with the older ignition system, so I am learning.
--
94 940 owned 20+ yrs, 330k+ miles; 93 940; 89 780; 05 XC90 for the wife; 07 S60 for the daughter. Sold 88 760 and 92 745T.
|
|
|
|
|
