1.3 Motronic Up-Grade & 2.7i How To

[lateracer]

After reading the first post it is plug and play!

Where on the first post (or any of them) does it say 1.0 to 1.3 is plug and play?

[Imagine_M]

After reading the first post it is plug and play!

Oh and for the guy wanting to weld the combustion chamber.... dont do it just get matching pistons if anything... why destroy a head...

[lateracer]

I've got a 06/86 e (Motronic 1.0 system) that I'm doing a 1.3 upgrade on. I'm ready to swap out the harness and the 1.3 harness fits right on to my stock c101 connector. I know when people had the older square connector some wire splicing needed to be done, but I'm not sure about this.

Do I need to move some wires around or can I just plug the 1.3 harness into the 1.0 connector and go?

I took a photo and there are clearly some pins on the 1.3 side that won't be connected to anything on the 1.0 side.



I think the answer to my question is "Yes" but I'm not sure if I've read about systems getting fried from just plugging and playing. Wanted to be sure before I reconnect the battery.

[EtaSport]

Yea, your high altitude will make it feel even more sluggish. However it may be negligible. My suggestion is to mill the head as much as permissible then correct for cam timing with an adjustable cam gear. It is a relatively smooth running combination from the ones I've seen.

[dougs87325is]

Thanks for the reply. What about heli arc welding the combustion chamber, filling it in, then milling it?,clear the area around the valves? Oh well, I went outside and started pulling the eta block. I'm moving is the problem, will be driving this across country once the swap is done, just wanted to make sure it will run okay, Im already at high alttitude, just want to make the trip with no problem, driveability etc...Thanks again!!

Doug

[EtaSport]

That question has been documented all over the Internet and forums, you just need to search. Yes you can put an I head on an e block, yes it will run okay, yes you will have stupid low compression which is okay I guess if you plan to turbo, and yes you will have an unmatched piston/combustion chamber design.

[dougs87325is]

One more time, haven't seen a direct answer to this really. My 87 325is car and head swapped on a 2.7 eta block will run okay? I have the chance and parts to do this and want to turbo later on, drive for a year N/A, would it be okay, computer etc...

[Paukert11]

what did you do for the starter. I am a little lost on that part lol

[mph10909]

Hey I'm new here. I just finished up the swap and when I went to turn the key nothing happened. Any clue what I may have done wrong everything is hooked up right. Im lost thank you.

[lateracer]

e harness is trash period. :)

The e harness runs flywheel sensors and the i harness runs front crank sensor, no way to rig it....

Hah! Alright, trash it is.

So I'll need the CPS and timing wheel for the front. Other than that, are there any other sensors that need to be swapped out?

[kenika65]

e harness is trash period. :)

The e harness runs flywheel sensors and the i harness runs front crank sensor, no way to rig it....

[lateracer]

Does anybody have the details of converting a 87 325e round plug into a 88 325i wiring harness? This is the only part holding up my 2.7i upgrade

It should plug right in and work, but you are going to want to run the 88 harness for best results

Are the specific differences between these two harnesses really big, or is it worthwhile to modify the e harness if an i harness is difficult to source?

[kenika65]

^It turns it in to a whole new monster ;)

[E30QC]

yeah, i thought this was the 2.5 head on a 2.7 block..
anyways, so what does the chip do? i know it raises the rev. limiter, but apart from that it won't play too greatly with advance and so on..

[e30pwr]

taft - that is my plan of action, lol