Hey guys! 

First of all i'm sorry that i'm posting this in a Skoda forum, but i own a vw polo 9n (basically the same car as a Skoda Fabia haha) but the polo forums are completely inactive, so i'm posting here. 

 

So the story is that i own a vw polo 9n 1.2 3 cylinder azq engine. Well the engine has completely died and i wanted a little more power out of the car so i decided to swap in a 1.4 16v bky engine from a newer 9n3 polo. Before you start with the (it's not worth it just buy an another car talk, this car has a very deep sentimental value to me and i bought a donor 1.4 9n3 polo that was crashed in the rear for 90euros)

Well my mechanic did all the work as for swapping the engine and all of the wiring loom and today we tried to start it up. well the ignition was fine, the fuel pump came on when opening the door as expected but the real problem that there is no spark whatsoever. we didn't change the interior loom and when comparing the fuseboxes we noticed that there was an extra fuse in the 9n3 that is missing from the 9n. it's fuse 45 and it's supposed to be the engine control fuse. Well i took out the dash from the 9n3 to probe around in the wiring and i found out while doing a continuity test from fuse 45 to the bulkhead connector there are two wires going in to a brown connector from the fuse to the bulkhead connector. i did an continuity test on those at it seems the wires are going straigt from the fuse box to the bulkhead connector bypassing the ccm. the two prongs on the bulkhead are connected when the fuse is placed in and dissconnected when the fuse is pulled out. Well tommorow i'm gonna try to connect those two wires together from the engine side, but i'm worried about the ccm, i'm thinking there wires must be somehow powered,  Any ideas will it even work? i appreciate the answers. 

 

Oh and i'm from Lithuania so excuse my poor English skills haha

Fuse 45 is fed directly from the ignition switch so does not need to go through any modules. 

You need to get that power wire to pin 4 of the engine ECU, I think.

What year was each car built?

How much of the wiring in the engine bay has been moved from the 9n3 to the 9n? I think it may be necessary to move the wiring loom that goes between engine ECU and bulkhead connectors, if you didn't already?

Thanks for the answer! The 9n is built in 2003 and the 9n3 is from 2006. We put the entire 9n3 engine bay loom from the 9n3. On the bulkhead connector there are 2pins missing in the 9n that the 9n3 has. I’m attaching a picture of the two pins. J stands for black and purple wire and M stands for blue and white i think. Also we swapped the ecu, instrument cluster and the immo chip in the key for the immobilizer

I think I may be able to help more a little later today once I've woken up a bit more and have a big screen in front of me. 

 

@Reamis @Wino - Meantime, which ECUs have been ported from the donor car? I've this notion that the ignition immobiliser may have activated because it's in a different car.

So it looks like the one you've labelled M is pin 2, and the one labelled J is pin 3.

Pin 2 needs a connection into the cabin to fuse 37, and pin 3 needs a feed from fuse 45.  (Both 15 Amp fuses)

Edited 8 April, 20215 yr by Wino

32 minutes ago, KenONeill said:

which ECUs have been ported from the donor car?

 

3 hours ago, Reamis said:

Also we swapped the ecu, instrument cluster and the immo chip in the key for the immobilizer

 

I think that should be sufficient. 

Well wr sorted the problem out. Just had to feed 12v to the fuse 45 wires on the bulkhead connector and voila, the engine started up without no problems hah

Ignition switched 12V? 

The connection that's supposed to come from fuse 37 should actually be the output of the fuel pump relay rather than ignition switched 12V, not sure how much difference it would make in practice.

Yep. Ignition switched 12v. Well the engine runs like butter and everything works now. Noe to retrofit the fog lights wiring and put on a 9n3 front end and the car is finished haha

20 hours ago, Reamis said:

Well the engine runs like butter

Good news! 

Here is the car almost finished 😁