1.3 Motronic Up-Grade & 2.7i How To

[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]

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.

[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.

[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]

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]

I guess what I meant to say is that it doesn't say anything about having to rewire and as detailed as it is I'm sure it would say if needed...

[hurttech]

I'm going from an '85 E and using an '89 i top end and engine harness, where would the tachometer get it's signal from?

[hotballs]

There is a 3 wire plug on the interior of your car that used to connect to the eta harness right next to the DME. It has black/yellow/green wires. I believe the black wire is for the tach.

[hurttech]

There is a 3 wire plug on the interior of your car that used to connect to the eta harness right next to the DME. It has black/yellow/green wires. I believe the black wire is for the tach.

I tried connecting the engine speed output from the 1.3 dme to the black wire on that connector and got nothing. Is there another wire that needs to be connected in order for the tach to read the signal?

[acolella76]

sorry if i'm beating a dead horse, but does anyone have a DIY for just replacing the sensors and electrical nonsense from an 85? I'm going to use my E head, I cams and springs, and headers, and swap everything else over i need to run the 173 ecu. I just don't really know anything when it comes to the electrical part.

Also, would it be fine to just cut the sensors and leave them in the bellhousing so i don't have 2 holes?

[call me jack]

Dual exhaust.

Can some body clairify why they mean when when they say "Dual exhaust"

I have a feeling they're refering to the manifold, so with that said, i could just use a header, right?

[acolella76]

Can some body clairify why they mean when when they say "Dual exhaust"

I have a feeling they're refering to the manifold, so with that said, i could just use a header, right?

The 318's and 325e's headers come together just before the cat converter, and from then on the exhaust is 1 pipe, but on the 325i the exhaust is 2 pipes the whole way.

[call me jack]

thanks alex. another question though

how much should we be looking to spend on this conversion? and any tips on where we might be able to find the parts, other than craigs list?

[lateracer]

The for sale sections here and on some of the other forums will have most of what you're looking for.

Prices vary depending on how much you find grouped together really. I scored an intake with fuel pressure regulator and throttle body for about $100, head for $150 shipped, harness for $60 and so on. In the end, I think the total cost for an i head upgrade would have been around $500 once I included things like gaskets, timing belt and other things. I say "would have been" b/c while I was piecing the last few things together, I found an i motor (b25) for $200 on CL.

If you're looking to upgrade a seta with a motronic 1.3 system in place, I think you can get away a lot cheaper than I did. Otherwise, just buying a used i motor/harness/DME is likely a better choice. Being able to rebuild the motor from top to bottom the way you want it and get to other maintenance things like the oil pan gasket, rear main seal and hard to reach hoses will result in something you can just drop in and forget about for a while when you make the swap...and after a job like this, chances are you'll want to drive instead of turning wrenches for a while.

[acolella76]

lucky for me, the previous owner totally rebuild this slow ass 325e engine lol


so, where is the connector i'm supposed so splice/change to the round c101 plug? I'm normally not this much of a noob, i swear