Friend bought a car, confused on motor.

[e30strokr]

Vin on door states it is in fact an 89 325i everything else does in fact point to magic

just swap an "I" cluster and see what happens...


but honestly if the car runs out of breath at 4500 it has to be an E motor...

[TobyB]

the "e" coding plug which would limit the revs to 5k.

err, rev limiter's in the ecu, not the dash....

...and by 1989, an e ecu won't plug into an i harness. I don't think.

t
wasting time on the internet.

[McGyver]

err, rev limiter's in the ecu, not the dash....

...and by 1989, an e ecu won't plug into an i harness. I don't think.

t
wasting time on the internet.

I'm pretty sure you're correct on both parts, but the coding plug in the cluster could show some funky stuff.

OP, since it's obvious someone has been messing around with stuff in that car, the ONLY way to know whats going on is by reading the part numbers off of the head and ECU.

Side note, an early cluter from an eta with 5 red SI lights should not be compatible with a late car that came with a 3 red SI light cluster. Something about the alternator not getting the correct signal to allow charging...

[kid325e]

Not sure if it's been said but I would unplug the ECU and verify if the ECU is a two row (Motronic 1.1/325e) or three row (Motronic 1.3/325i).

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[Cephas]

Ask the previous owner for details?

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[Jean]

It should not require 3 pages to figure out what car/engine you have OP. :)

Pull the DME and report back, and get some numbers off the head.

[Chaseb124]

It should not require 3 pages to figure out what car/engine you have OP. :)

Pull the DME and report back, and get some numbers off the head.

I plan to, like I said though it’s not my car just attempting to help a friend out, I know what my car is haha, but he is in Canada right now so once he is back I will find all the numbers I can and report back!

[nando]

You have an M20B25. The tach means nothing - the eta tach has the same sweep, but the numbers are different. so ~4500 is basically the same as ~6500. They must have swapped in the eta tach at some point.

If you had an eta coding plug and an M20B25 the tach would go all the way around because 7000rpm would be at like 7 o'clock.

[Chaseb124]

ECU is a 173, and the head is stamped 885, sounds like an I to me!

[ForcedFirebird]

CPS or AFM will cause a faux rev limiter. It's common for diy guys to run the CPS wire behind the water pump and not use the plastic protector, pump pulley rubs through the wire. ...or the AFM has a dead spot on the wiper track.

[flyboyx]

CPS or AFM will cause a faux rev limiter. It's common for diy guys to run the CPS wire behind the water pump and not use the plastic protector, pump pulley rubs through the wire. ...or the AFM has a dead spot on the wiper track.

I’ve purchased lots of non running e30s over the years because of the wp pulley rubbing a hole in the cps sheathing. Usually it runs with a bad miss or won’t run at all in my experience. I’ve seen the “dead spot” afm issue before too except when the rpm reaches the dead spot, the engine will start missing and running erratic in my experience. Both of those are definitely something I would look into.

I would replace the tach with an “I” version, run the car and see what you really have.

[e30strokr]

err, rev limiter's in the ecu, not the dash....

...and by 1989, an e ecu won't plug into an i harness. I don't think.

t
wasting time on the internet.

1988 SETA will...

[ForcedFirebird]

I’ve purchased lots of non running e30s over the years because of the wp pulley rubbing a hole in the cps sheathing. Usually it runs with a bad miss or won’t run at all in my experience.

I've had them finish long endurance races with a bad CPS and it sounded like a popcorn machine every time it went down the straight. Had them not start at all, 4000rpm "limiter", 4500rpm "limiter", misfires, even some seemed to run fine, but were down on power.

Also many many times have had the wiper track worn on AFM's. Move it over a bit and the car runs like new.

[MrBurgundy]

Once I had a CPS on an I car that an almost broken wire, which caused a limiter effect around 4k RPM, like forced said above.

It ran totally fine until unless you were in that part of the r3v range.