Well The customer brought us this mk3, For some minor drivability issues that he was experiencing, So after looking over the engine we realized some vacuum line were incorrectly routed, he also had a boost leak & missing vital engine sensors.

We also decide, to change plugs & while in there to do a compression test , good thing we did, The engine had two cylinders that were basically dead. So we began debating what the best course of action would be, rebuilding or swapping and we decided to swap.


Upadte:
So now after running the numbers we've decided to abandon the 2j swap & opt for the engine refresh.... We apologize, We understand a few were excited to see this happen.



So lets begin..

 

Now that the final decision was made, The engine was removed.

 

Got the engine on the stand & began the tear down.









Oil feed line: ( major safety issue)



Oil drain line restrictive kink:

 

So we got the engine Further disassembled: The head had some scouring on several cam journals:







Onto the block: the cyclinder walls were in suprisingly good shape but will also need machining.

The crank also had scouring consistent with the cam journals:







After removing the pistons , It was apparent why cylinder 1 & 6 were down on compression:

Cylinder #1 piston broken ring land:





Cylinder #6 piston broken ring land:

 

detonation. possibly a bad coil firing at the incorrect timing. cyl 1 and 6 both run on the same coil.

 

Def. Detonation the engine had 1 broken knock sensor and 1 not hooked up. Interesting observation BTW thanks.

 

well, when you run into shit like this, look into the common contributing factor. the fuel and air should have been ruffly the same on all 6 cylinders. the #1 and #6 are run off the same coil. it could be the coil, ignitor, or ecu that caused it to fire off time and cause detonation. then again, it could be the injector driver not holding the correct duty cycle to provide sufficient fuel to those cylinders. I just looked at the diagram. injectors 1 and 6 are fired together.



they are run from "#10" which if you look at the pinout is the top row, second from the very left. id check the ecu out. being that 2 cylinders that are linked together both fuel, and ignition wise are dead, it seems to reason its somthing in the engine management. not likely that both of those injectors failed

 

Thank you, I appr.that this is what it's all about,

However I noticed that you have a diagram of a 7m-ge and also stated that they are fired off the same coil, 1 & 6 are fired together but the 7m-gte uses individual coil packs unlike the 7m-ge, So they wont be using the same coil. so with that being said......

I'm leaning toward the fuel department.. but i do believe timing was also a factor based on the knock sensor issue.

or like you said ecu..

 

the ecu pinout for the injectors is the same on 7mge and 7mgte. and yes, on a 7mgte the #1 and #6 use the same coil(7mge has 1 coil only, and all 6 cylinders use it. thats why it has a distributor where the 7mgte has coil packs). there are 3 coils on a 7mgte. cylinders 1, and 6 are on 1 coil, cylinders 2 and 5 are on another, and cylinders 3 and 4 are on the last. and these same cylinders are grouped together on the injector firing for 7mge and 7mgte.

 

Yeah your right , 1 & 6 grouped coil...