Hi guys, I am new to this forum, introduced to it by Dale..thanks! Anyways, I have a bit of a mess on my hands and was wondering if anyone here has any suggestions, I will just copy the questions I asked recently from an email..
I bought a 1985 760t with a supposed "newer" b230ft and m47 tranny in it. My car is a 1990 740t, automatic. Yesterday I took both engines and tranny's out, and put the one from the 85 into the 90 (tranny and all) I got it all in and everything, but noticed that the dist. has a connection on it on the engine out of the parts car, where the engine that I removed (with the automatic) does not have this clip. I believe it to be the hall sensor, from looking at faq at brickboards, and everyone there says that I have to pull the engine back out and install a crank sensor in the bellhousing, as well as get a new flywheel. I am wondering/hoping that I can perhaps take the engine harness and ecu from the 1985 donor car and put them into the 1990, hoping 2 things. One, that I can remove just the engine wiring harness, and that is not all connected to the rest of the car's main wiring system..is this possible.
Secondly, I was wondering if the other portions of the car's wiring system for the 1990 will plug into the 1985 ecu?

Ok, so thats the deal..secondly, do any of you have any suggestions on where I can get the correct flywheel I need? I don't really want to pay $400 for a flywheel since i'm pretty much out of money..Anyways, sorry for the long post, and thanks for any help!

Sorry Gus for not answering that email...

Lotsa guys here will help you out.

Welcome...by the way...

I honestly don't know what problems you'd have if you used the old Dist, ECU, Harness in the new car?

Perhaps some of the instruments would be different? I'm not clear on it, but it sounds like a good idea none the less

Oh, and welcome!!!

- R

Whew! Thanks for the vote of confidence! That's the first "it's possible" attitude I have seen since I started asking questions about this sunday night! I pulled the engine harness out of the old car and am working on getting the ecu and its associated mess of wires out of the car now..any other advice/input/encouragement is welcome..
Thanks guys,

Your 90 has LH2.4, the 85 would be LH2.2
You are probably missing the Crank position sensor from the flywhee;/back of the block.

The sensor/bracket is 30 bucks from FCP groton, and you can pick up a flywheel for around 50 bucks. I picked up a flywheel from Ed Schram Motors in Surrey BC for 50 bucks plus 10 shipping on the bus.

Might be easier to go that route rather than swapping entire wiring harnesses.

Those ECU's won't match up at all I don't think. You'd need to swap all the wiring for everything, or be real good at cutting and splicing

Jordan

yup, 2.2 and 2.4 ecu's have different numbers of pins, so i wouldn't want to mess with the wiring. Pretty sure, like Jordan said, you'll have to change the flywheel and add the sensor. Otherwise, *maybe* swap distributors (I think they're the same though) and make sure you don't swap amms or any other electrical bits.

check pick your part for any manual transmission'd 1990-1992 740 or 1989 and up 240 for the flywheel and sensor.

Are the crank position sensors different from an automatic to the m47? I am brainstorming with a friend and wondering if it might be possible to drill my own locating holes for the cps in my current manual flywheel..I have access to a cnc mill, so I can get some pretty accurate holes. Also, is the ecu different from an auto to manual car? These probably seem like foolish questions, but I'm just trying to avoid buying more stuff..I have pretty much broken the bank until the stuff I am selling that I don't need from the 740 parts car starts to actually sell..

Ok perhaps I will try to just swap the flywheel..it does seem to be a much easier option...I have read that there are two different hole patterns, or two different number of holes that I may be looking at? What is the correct flywheel I am looking at, just one from a 90+ turbo manual 700 series car? Do I have to specify m46 or m47? I just don't want to make a mistake, and thanks for the help! Once I get this beast running maybe I'll take a ride out to calgary with my buddy who was born there and go to a meet! seeya guys..

The sensor itself is the same between manual and auto cars.

Hopfully your block (the new one) has the holes i nteh back for this sensor.

You want the flywheel that is 60-2 holes. I'd say it would be quicker/easier to find a flywheel instead of drilling all the holes.

Jordan

Funny...I was just talking to a machinist tonight about this. We have a 2.4 flywheel and were wondering how difficult it would be to drill a 2.2 or even a flat flywheel. A CNC machine is the ticket but, of course, it needs to be drawn up first...

There are essentially 60 holes...58 are holes and two are not. Simply put, the holes are 6 degrees apart. I'm guessing the position of the missing holes is critical...

just out of curiosity, if you had a 2.4 flywheel, wouldnt the holes already be drilled? I was following everything until that..anyways, good to know that the sensors are the same, since I already have one of those..now I just need ot find that flywheel..if anyone has one I will buy it! As for the holes in the block to mount the sensor, if my block doesn't have them, I shouldn't have a problem drilling and tapping it right? Anyways, thanks again, this has been a huge help.

Another question, maybe dumb, but here it is. This rpm sensor is the same for the auto and manual, and on the manual it is reading holes that are drilled on the friction surface, outside of where the clutch grabs, or if we considered a tire a flywheel, just for clarity sake, the holes in the manual flywheel would be drilled in the sidewalls of the tire, where the flex plates for automatics that I have looked at on ebay and such seem like the sensor gets data from gaps which are in the tread surface or wear surface of a tire..is this sensor really abot to read in two axes? Or is the bracket for an auto different from the bracket for the manual? Thanks again,

What Dale's saying is that we have a 2.4 flywheel to use as a pattern to determine the exact position of the missing holes, the position of the REAL holes, etc. We could then use that to copy the pattern onto 2.2 flywheels (which don't have the holes but are otherwise similar) or flat flywheels (that came on earlier cars, are much ligher and sportier, and have more clutch options available).

Both RPM sensors read from the same place, the tread. The holes are drilled radially from the flywheel (not "holes" really, just 1/2" or so deep) and they're formed by a punched ring of steel on the flexplate, but again the holes are arranged radially (the axis is not parallel to the crankshaft).

Has anyone mentioned yet that the 2.4 electronics are FAR superior to the 2.2 system? Has anyone asked why you pulled the '90 motor out in the first place?

I pulled the 90 motor and tranny out because the engine had a heavy knock to it, and and the tranny was ruined, and an automatic. I got a hold of a parts car with an m47 and great running b230ft, and obviously wasn't aware of the differences in electronics. No biggie though, since I haven't hooked anything up besides the tranny and engine mounts, I cann pull it back out pretty quick and put the new flywheel on..I just have to find one! I understand about the flywheel I think now also..thanks for the explanation!

Have you determined what year the block is that came out of the '85?