1.3 Motronic Up-Grade & 2.7i How To

[jeffnhiscars]

I now have ever conceivable part to do my swap and my last question (I hope) is regarding the exhaust manifold. I have a b25 dual pipe cat and cat back and I'm fairly comfortable that it will bolt up to my ETA exhaust manifold.

Since I'm un der the impression that the ETA manifold is a little smaller inside will that restriction be enough of an issue to justify grabbing a b25 or could it actually be better to keep the ETA manifold as the back pressure could help ?

...or does it really not matter

[Untouched]

Rough running

Hi all.

Recently converted my 86' 325 to a 2.7i with parts from an 89' 325i. I am having an issue with the throttle cutting out around above 2500 RPM (hard to tell as I don't have the tach hooked up). The car idles fine, but starts cutting with more then 1/4 throttle applied. If I keep the throttle open, it will rev up for a second, cut off, rev up, cut off, etc. Any idea what could be causing this? It does this at all temperatures and with/without o2 sensor or throttle position sensor plugged in.

The car ran well before the conversion; so I should be able to rule out old parts still on the car (fuel pump, filter) and focus on the new parts.

[e30onBBSs]

The bolt patterns are the same but the port sizes/shapes are way different

thanks modernist (2.7i expert)

[modernist]

The bolt patterns are the same but the port sizes/shapes are way different

[e30onBBSs]

Checked realoem and the intake manifold gaskets are different from b27 to b25. If I want to use b27 manifold + b25 throttle body I would use the b27 intake manifold gaskets to attach to the 885 head? The b27 manifold bolts up to the 885 head right?

[modernist]

The separate injector harness started in 5/88. The complete harness from any Motronic 1.1 or 1.3 M20 will work.

[jeffnhiscars]

This has probably been explained but I'm not about to read 28 pgs again.

Will an IX harness work for this and how many cars actually have a 1 piece harness vs a separate injector harness ? Realoem shows harnes PNs changing every 6 months

Does it even matter as long as you get the whole thing ?

[modernist]

Just so y'all know, there's no reason to cut the hole in your firewall bigger. Just remove the big plastic sheath from the ECU plug, it'll fit through fine then. I have mine ziptied to the ECU, if you wanna be meticulous put the sheath back on once it's through the hole. No muss, no fuss, no potential for additional rust problems down the road.



There are a few screws and a rubber gasket holding the plug in the sheath -- once those are undone you can gently slide the sheath down the harness. Split it with a sharp knife and pry it open enough to slip the harness out. I did mine without breaking it.

[whitebulat22]

Turns out I was just fine with the tach connected and the main & o2 relays not in the wrong place. Ill have to edit once my parts arrive how it runs when warm. Idled not bad, didn't like load at all. It's being challenged with wrong displacement 2.7, m30 afm, m50 injectors, and an eta exhaust broken at the downpipe. I'll see just how adaptive these computers are.

Edit: Car does not like m30 afm, needs to be kept alive for a bit and randomly loses all power sometimes. Put a m20 afm in, I don't know if it's even misfired once in 150 miles. M50 injectors and 2.5 bar fpr.

The new product doesn't have the same 1200 rpm grunt anymore, but anywhere above the power is equal or greater. Very satisfying when I get above 5000 and it just keeps climbing faster. Smoothest noise I've ever heard coming out of my tailpipe, it instantly started up and felt perfectly refined. Would do again

[StereoInstaller1]

I'd be happy to help, but I'm 1200 miles from my desktop PC, I can't do the ETM gracefully from my phone, sorry

[whitebulat22]

I have a question on the c103 from my 86 splicing into an I harness. I found it's the white glovebox connector, 3 wires: black to tach, green/red to obc main relay which can be ignored, and yellow/white to econometer. I'm having trouble finding which black wire is ecu pin 6 and which whit/black is pin 32 to match with the respective c103 wires. Am I stuck guessing until I hit the right one? Also out of curiosity which is the one that tells the ecu when it's time to wake up? Thanks!

[binnavert]

Parts for e2i swap

If anyone in SWFL area,I am parting out 1990 325i.Front end damage.I wanted manual swap, motor and rest of Briliant Rot/tan sport interior (seats rough) sedan avail.Willing to swap/ sell parts VERY reasonably. Need to remove from current location PRONTO. U pull I pull ,whatever. Shipping CONSIDERED on part by part basis.Not looking to make a fast buck,trying to get what I need in return. style 5's?? :D Otherwise she has a date with scrapper REAL SOON!!

[jaxone]

Numbers ?

Hey guys.

I am in process of swapping my engine with a 2.7 eta with 2.5i head.
Engine is done and should run fine ....

In the meantime I also got cheap an 325i with sport 288 cams ...

I am a bit in doubt on what should I install.
Should I put the 2.7 with the 2.5head or the 325i with the cams ?

Has anyone dynoed the 2.7 conversion ?
The 325i with the cams pulls 194hp. but never dynoed a 2.7 with 2.5 head.

Thanks in advance.

[deeze30]

I've read thru alot of this thread and some others and think I have enough info for what I'm about to do but would like you guys that have done this confirm I'm doing it right.

I have an 87 325is with exploded pistons and completely ruined bottom end. Today I bought a running 88 325 from a friend of mine for $650. Based on everything I've read, all 88 325 cars have the super eta engine. My plan is simply to take the lower end out of the 88 super eta and put it in the 87 325is and then put the head, intake and all of the other parts from the 87 325is back on and that will complete the simple conversion for me. Obviously the head will go to the machine shop first for pressure testing, etc.

So engine wise, everything on this 87 325is will be from the 325is except the bottom end which will be from the super eta.

Extra bonus, the 88 super eta is a manual and the 87 is auto so I will be swapping the manual over to the is as well.

It sounds about right. I'm doing the conversion also except i'm using an eta block

[dudem3]

Except for the pistons, which is why I'm a noob at this.