Calling the gods of ECU's....HELP PLZ

Hiya all,,

OK... the problem,,
AM going to install a LINK G3 ECU which has a LinkAdapter for a MR2 mk1 Turbo ( from which the link came from )

Normally it should be pretty straightforwad but as always with me nothing is straightforward

As the Link comes with the Adaptor ( which are different plugs on a MR2 [same s a 185] ) in all of Links wisdom they have done away with colour coded wiring so they are all white ( first problem)

This can be overcome with MR2 ECU plugs with wiring to make a patch lead between the 2 (first problem solved in theory)

Second problem in addition/continuation to first

I have a JDM ECU with no PIM wire and very little documentation on ECU pinouts but have sourced what i beleive to be the nearest correct one ( may actually be correct one )

But there are a few variations i need help with on both the 165 side and MR2 side.. I have drawn up a wiring conversion chart with all but 5 wires on both ECU's ( this has been drawn up on the wiring colours of the MR2 as i had the plugs with wiring to hand................

Can anyone help me sort out the missing links? i have put at the top and bottom the wires i have missed/are not there/ or do not correpond to anything i know of Also a breakdown of what the :

FPU,,WUN,,TIL,,W PINS ARE ON ST165 AND

FC is on MR2........ pic attached .... sorry cant seem to get pic any bigger but have added link to pic also to see if u can get larger lol

http://pic60.picturetrail.com/VOL1753/1156...3/387886049.jpg


Help really needed on this one please

Jingo

Are all the wires from the link white? or just the ones on the patch loom? Personally I would ditch the adapter and hardwire it all in, much quicker and easier as long as you don't want to ever remove it.

Unfortunatly all the wires are white

Ok... am a little further (ish)
WIN is ========= Intercooler ECU (so dont need to worry about that ons as going front mount)

W is ========= Warning Light (found that one DOH)

FPU is ========= Fuel Pressure VSV ( again not sure on where to wire that one in and no corresponding pinout on MR2 ECU

E22 is ========= Sensor Ground

THA2 may possibly be another air temp switch

On the 185/MR2 Turbo, the circuit opening relay for the fuel pump is controlled by the FC line on the ECU, but looking on the 165 wiring diagram, the same plug on the circuit opening relay connected to the fuel pump is run by the AFM...

I will be running FMIC and ditching the AFM ( which could create new problems as my ECU has no PIM wire for turbo pressure sensing and that is controlled via the AFM )

(st165 jdm doesn't have fuel cut based on pressure from the PIM. It's measured with the air flow. So i cannot boost more than 10 psi.)

FC on MR2 ECU seems to control the fuel pump but i do not have that wire so how do i overcome? ie what wire does the same function on the 165?

I will be running the boost module on the LinkG3 so can i presume that the PIM wire will not be needed from the MR2/185 ECU pinout?

Sorry I cannot help you anymore, my 165 knowledge is not really up there. It sounds like you need to find a list of which wires (by position not colour obviously) on the link do what if you don't already have this available. Then use the st165 bgb to match them all up. This is what I had to do for my megasquirt installation.

On the 185 FC controls the circuit opening relay, it isn't necessary to use the FPR pin also, the link must have a fuel pump wire of some description, use it for FC. This might be the same as the 165? just have a look at the diagrams and work out which wire controls the COR. There are surprisingly few wires needed to run the 3sgte. You will not need PIM. Once you get rid of the stock ecu you will not have a fuel cut so you will not need to worry about it. The link will no doubt have the option to use a map based fuel cut at whatever point you want to set it. I presume the link has its own map sensor?

It sounds like you need to find a list of which wires (by position not colour obviously) on the link do what if you don't already have this available. Then use the st165 bgb to match them all up. This is what I had to do for my megasquirt installation.

Click to expand...

Click to expand...

Well the Link was wired up for an MR2 turbo MK1 and i managed to gt the wiring plugs from the car it was in and pinout diagram of that and then managed to get my JDM wiring diagram ( not in the BGB as JDM ) os have managed to wire from that bar a couple of differences

Another silly question is I am putting my IAT sensor where the cold start injector is and obviously have to "cap" the fuel pipe

"Any chance anyone knows the thread and size of a bolt to cap it?

Thanks for replies TW2

I made a new manifold so I also had to cap off the cold start injector port on the rail. I used some copper crush washers under a bolt. Sorry all I can tell you is that it needed a 14mm socket and the pitch will be smaller than you think. My guess is M10x1 or M10x1.25. The rest of the rail is M12x1.25, it might be the same. Just try some spare bolts and see what fits, you can even measure the thread with a ruler.

Bolt size in case anyone wants to know is M8 x 1.0

Maybe this thread will draw the experts I need to consult.

I swapped a 93 JDM engine\harness\ECU into a 90 US All Trac. I found out Id have to repin my chassis to ECU plug to make it work. And aparantly its only one wire. Can anyone tell me which wire to move and to where? Its the only thing holding me up. If it runs, Im done. Been working on it for 4 months.

Thanks,

If I were you, I would get both diagrams for both USDM and JDM and work it out and confirm every wire one by one. It shouldn't take you more than an hour or two and then you can know 100% for sure that you have every single bit right. This is how I did it when wiring in my megasquirt. I confirmed every single wire, not just by colour and plug but that it actually went to where the diagram said it did. I imagine the speedo is different? My 1990 JDM has a electronic sender. I have heard that they used cables in some of the USDM's?

Ive done that breifly. The problem is that there are some wires that only exist on the US model and vice versa, so its like theres no way, at least for a novice like me, to know what to keep and whats not needed and then where to shuffle them.

Yes the US uses a mechanical speedo cable, I swapped that on the tranny so my speed gauge would work. And I have the sensor plugged into the harness just incase, dont know if that will help or hurt me. I thought the ECU might need the input but yet if its reading zero while driving, who knows how that will cause the car to act. But it should at least start with the sensor plugged in. If I ever even get to that point.

Ive been told only one wire needs to be moved. But not which one.

There cannot be too many wires in the engine to body connection. If you want to post them I might be able to tell you if you need them or not, or else someone else will.

Here is my old setup and my new setup, Ive been told that only the FC wire needs to be dealt with. It comes from the Circuit Opening Relay and goes to different spots on the different ECUs. But its not as easy as it sounds, I did it and it wouldnt start. So I dont know if I did it wrong or what. It is related to the fuel pump.

FC goes to the circuit opening relay. You used the loom from the new engine right? so this means that the pins etc are fine for the ecu. You need to verify that wire actually goes to the circuit opening relay. This is a small approx 30x30x30mm plastic box just to the front of the ecu under the centre console, it is the only wire which comes from that ecu plug so shouldn't be too hard. You need to find the diagrams for the body harnesses rather than the ecu since this is where your changes are. By using the loom for the correct ecu you have hopefully guaranteed that all the wiring is correct between the ecu and engine. It is just the ecu/engine and body interface which might be the problem. If I remember correctly the connectors you want to ficus on are IG1 and IG2 and these are two large plugs which run with the engine harness. They may even have similar colour wires on both sides of the plug to make matching easier but don't rely on this.

Ive been thru that past 2 days. The pin 4 from the circuit open relay is supposed to go to the medium sized ecu plug bottom row 3rd from right like in the diag I posted. But still didnt fire.

Sorry thats about the limits of what I can suggest. FC runs 12V through a resistor to the ecu. Maybe this needs to be grounded to enable the fuel pump relay? Can you crank? Spark? Nothing at all

It does crank. And that japanese gear reduction starter sounds awsome. To bad the engine wont start. I tested the wire splices I did and they are fine. I dont know how to interpret the results on the circuit open relay.

I hooked up the battery. Everything is plugged in.

with the tester on pin 1 and pin 2 (fuel pump switch) of the COR, key to off is at 0.00, key ot acc is at -0.00, key to on is at .63. didnt try turning key to start since fuel pump should come on with key to on. Does this tell us anything?

So you have spark? Timing is correct? So basically it is only the fuel pump which is the problem?

Maybe someone more knowledgeable could step in. It looks like a standard 3 pin relay with 2 more pins which appear to only operate during cranking? It is definitely not a standard 5 pin relay despite having 5 pins. My guess would be to try with FC grounded but this may be totally wrong, don't do this if you are unsure.

It turned out that my fuel control wire colors were reverse of the BGB diagram. So I wired by color instead of by pin position and , VIOLA. Instant All Trac on toast!

Its the funnest car Ive ever driven!