SOHC Auto to DOHC manual conversion

Thanks for that Masterfix, it's good to se actual photos as they realy help. I'm starting the conversion in 4 days, with a time limit of 3 days /ubbthreads/images/graemlins/jawdrop.gif how do you think I should cut out the extra holes for clutch and shifter? maybe drill 1/4" holes and use a round/half round file to open it up?

Cheers, Justin

 

[cspetros]

I was actually able to fit a SawZall (reciprocating saw)(the VFaq says that there is not enough room on DSM's for this) with a metal cutting blade down there to cut the holes for mine, but I had to file the edges, as they were a little rough. I used a drill for the bolt holes.

You will run into a slight problem with the shifter cable hole; on factory manual trans. models, there are 2 nuts welded to the firewall for the securing bracket bolts to screw into. These nuts aren't present on automatic cars. I simply drilled my holes, and used 2 loose nuts. It was a bit tedious, but I got both bolts securely fastened.

I'm waiting on my flywheel to get back from the machine shop before I get my manual transmission swapped in (f5m33 model from 1990). The auto shift cable penetrates the interior through a hole in the raised center floor area beneath the radio (unlike where the manual cables go through the firewall).

Hope this helps!

Buzz post... /ubbthreads/images/graemlins/hsugh.gif

 

Thanks for that, do you think I could use a couple of rivnuts where the nuts are suposed to be welded in? Another question (Important) are the driveshafts (halfshafts) any different with an Auto and Manual? will I have any issues there? will the old exaust bolt up to the dohc manifold?

Just don't want any suprises on friday when I hope to get the motor in.

Cheers, Justin /ubbthreads/images/graemlins/cool.gif

 

[cspetros]

Rivnuts would work. Just anything to secure the bracket to the firewall. There's also a rubber gasket that seals against that hole with the bracket.

Regarding the axles for FWD models, the SOHC axles are different than those on DOHC models. The outer CV joints are different. I am pretty certain that they will still fit without issue, but I'm sure there is a reason for the difference in type (max. torque difference maybe?). The spline counts are the same.



The exhaust downpipe is identical for non-turbo models; you will have no issues when connecting the DOHC manifold. The difference is at the other end; DOHC models have a dual tip, while SOHC models have only a single tip.



/ubbthreads/images/graemlins/smile.gif

 

Thanks for that, am I correct when I read that image it says that Auto drive-shafts are 2mm shorter per side? will this give me any trouble? /ubbthreads/images/graemlins/uhh.gif

 

[cspetros]

The ones on the bottom of those lines are for the DOHC axles (that ' mark is supposed to be a * ). The A/T and M/T are only for those in the AWD column.

I didn't even read that when I posted it, but it looks like the DOHC axles are 2mm shorter. I am not sure if this alone would cause any issues, but I am willing to bet that the SOHC axles are not as strong as the DOHC axles. When I did my swap, I got rid of the SOHC axles and put a DOHC set in.

Hopefully someone will chime in on this! /ubbthreads/images/graemlins/worthy.gif

 

HEEEEEEEELP /ubbthreads/images/graemlins/bawling.gif /ubbthreads/images/graemlins/bawling.gif

Got my loom today and all the plugs are different, it's from a dohc galant, all the same wires are there just different plugs and on my motor the sensors around the throttle body all go to one big plug. I've managed to find out where everything goes, mostly just by guessing based on number of wires per plug, where they go, colour, thier proximity to things that seem 'right' etc.

Just one thing I can't work out, that's my coil pack. On my motor the coil pack has 4 wires going to a square 4 pin plug, underneath it is what I think is a condenser, it has 5 pins 3 side by side a space and then 2 together, no wires come out of it. How can I wire the loom's plug to my coil pack and condenser /ubbthreads/images/graemlins/confused.gif /ubbthreads/images/graemlins/bawling.gif I've rented the things I need to start on this in 2 days /ubbthreads/images/graemlins/frown.gif I figure I can get a type of spade connector on the posts on the condenser, just need to know how to wire it

My looms plug and beside it what must be the plug for the aircon

Here you can see what I'm talking about colours are on the masking tape

THANKS, in advance

Just after posting this I tried searching some DSM sites, it seems I have a 91+ harness and 90 engine and ecu /ubbthreads/images/graemlins/confused.gif what do I need to modify to get this to work? /ubbthreads/images/graemlins/bawling.gif

 

[misterfixit]

Get a 91+ coil pack and a 91+ ignition transistor. don't hack those connectors about.

Rich

 

Thanks Rich,

Will I need to change about any pins on the ecu? I was reading something about when mixing 90 with 91+ harnesses or vice versa that pins 6 and 14 need to be swapped /ubbthreads/images/graemlins/confused.gif that was on an Eclipse though.

Anyone else have any ideas /ubbthreads/images/graemlins/frown.gif

 

[misterfixit]

Yes probably, if your ecu is a dual board then you will have to swap the wires, ir its a single board, then you shouldn't.

All thesingle boards have the same pinout arrangement.

Rich

 

Thanks Rich,

Yes mine is a duel board. I talked with the wreaker and he said they might have the right harness, so fingers crossed /ubbthreads/images/graemlins/uhh.gif if not then I'm going to have to modify some things I guess. Do you know exactly what pins I have to swap? is it the 6 to 14, 14 to 6? what one of the three ecu plugs is that? Sorry for being such a noob, electronics are very confusing to me /ubbthreads/images/graemlins/blush.gif

Regards, Justin

 

[misterfixit]

If it were me i'd be swapping to a single board setup.

I'll qualify that, a datalogger won't talk to a dual board.

Rich

 

I got a new harness, the only one they had that was closer to my motor was from a 89 galant MX automatic (hope I don't have a problem with my reverse lights /ubbthreads/images/graemlins/uhh.gif) The coil pack and resistor plug up now, but the sensors still have different plugs /ubbthreads/images/graemlins/frown.gif I can wire them up but I'm not sure about one.

Here is the big plug on my motor


And here is the plug on my loom that I think goes to the TPS (the three green ones) and the throttle switch (the black one)

So if I'm right then the two blue (yellow blue, red blue) and the black wire have no where to go on the loom /ubbthreads/images/graemlins/dunno.gif

 

Ok, I've been thinking this over and searching for more than an hour, what is this thing?

and do I need it? because my loom doesn't seem to have any wires for it /ubbthreads/images/graemlins/confused.gif

 

[misterfixit]

That I think is a fuel octane selector. Is there an oxygen sensor on your exhaust manifold?

Lets have a clear pic of your throttle body. The big plug is likely to be the airflow meter, later JDM cars had a temp sensor on the afm and hence went to 8 pins over 6.

You really don't want to be mixing and matching components off all those years and NZDM stuff. Is that an domestic NZ engine?

Rich

 

Thanks Rich,

No, there is no oxygen sensor on my manifold.

It's not the AFM, that comes out of the end with the trans plugs and fusebox plug.

I know idealy I would get a harness for this motor, but this is all the wreker had /ubbthreads/images/graemlins/frown.gif

My ECU and MFI relay came from this motor, so surely I'm not going to have to many issues /ubbthreads/images/graemlins/confused.gif

I'm thinking my motor might be an NZDM motor, I was told it would be a good thing if it is because they are a lot faster than a JDM motor, but now I don't think so /ubbthreads/images/graemlins/bawling.gif

 

[misterfixit]

the only issue you have is on the configuration of the ISC servo (yours is an early throttle body) the configuration of the ignition circuit. You will be matched rightly as you say on the ecu, but you'll need to transpose the fuel selector onto that loom (i'll dig up the diagrams for your MPI once you're set what you need.

If you are going to be upgrading past this conversion, then I'd swap the throttle body, ignition coil, ignition transistor, exhaust manifold and ecu to the later generation. Once there you'll be cooking on gas.. It'll be more efficient with a lambda sensor and no cat.

If money is tight then yeah its possible to convert your loom across, but you'll need to break into shielded circuits to sort the ignition lambda/fuel selector and isc stuff out.

The wire swap on the ecu end is a simple thing to allow the ECU to be swapped, but assumes the engine is hooked up correctly. So hell, you could even just sort the engine bay gunge and use your old ecu.. but the falldown here is that ecu will be looking for the fuel selector. and that will need fudging.

Rich

 

[misterfixit]

just a quick one, whats the partnumber on your ecu? and the e2t number...

 

Thanks for all the help /ubbthreads/images/graemlins/smile.gif

ECU has

MD132959

E2T33378

9812 A

I was searching it last night and all I could find was "4G63/e33a-90 M/T"

My loom does connect to my coil and transistor, when the first loom didn't connect to them I made sure the next one would connect /ubbthreads/images/graemlins/mad.gif instead it didn't connect to other things. the harness came out of a "89 Galant MX import"

Here is a good clear pic looking over the loom/manifold



The intention was to start this conversion today but since I have school monday I thought time might be a bit tight so canceled my booking to hire an engine hoist for two weeks untill I finish my course, then I will have like a week to get it done. /ubbthreads/images/graemlins/laugh.gif

Cheers, Justin

 

Here is a labeled picture of the manifold/harness area

And a picture of the label on the side of the ECU

MFI relay

Money is pretty tight, I have some to use in case I REALY need to though.

How can I say thank you enough for your help?

P.S. do I NEED that octane adjuster? sombody mentioned to me that the computer can adjust without it /ubbthreads/images/graemlins/confused.gif and that octane adjuster, is that a fill-in for the oxegine sensor?

Justin /ubbthreads/images/graemlins/cool.gif