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hi i recently bought an mx3 that needed alot of care ...... first off the mx3 in question is a 95 4 cylinder 1.6 DOHC and besides muffler and brakes and tires and usual things that needed replaced .... there were 5 sensors unplugged and no where on the harness to plug them into ........ so i went out and found a 96 4 cylinder 1.6 DOHC almost the same thing ..... except the plug in to the computer was different so i swapped out the computer and harness together and got most of it working ........ EXCEPT ..... the coolant fan still doesnt come on and i have it wired to a toggle switch so i know the fan works and so does the temp gauge ....... are there any ideas on what it could be causeing the fan to not kick on? im sure i will be asking more questions as this car is really not in that bad of shape i hope someone can help me out with this issue it would be greatly appreciated also ........ wen i start the car .... it wants to die right away .... before i replaced the fuel rail harness it was starting properly since i changed the one part of the harness(fuel rail wireing) it hasnt run right ..... i start it and it dies i start it a second time and it starts perfect ........ again i hope someone can help me out with these questions please and thank you

Sounds like you made yourself quite a mess.

Please use proper punctuation and space out your responses some, that is terribly hard to read. Since I'll be helping you, you can help me a little.

You may have moved from OBDI to OBDII between an early 95 model (built 94, sold 95) and a 96. That would explain why there were a different number of plugs between the ECM's.

Some models used both a coolant sensor (green) and a fan switch (black). If your coolant neck doesn't support the fan switch, you need to drill and tap a new spot for one.

What else is extra/missing on your harness/car? Your best bet is to find a complete early 95 or 94 harness and swap that in with a B6DE ECM. If you post in the [WTB] section someone will likely help you out. Remember to include your location.

For now, the starting issue is probably a metering problem. Did you take the airflow meter that matches your current harness and ECM?

Since you've done so much modifying on your own, this will be hell to help you with. Thats why I suggest you go back to a factory harness and a proper harness/engine/ECM/airflow combo.

the unplugged sensors that were unplugged were mas sensor....... one of the o2 sensors ..... temp sensor ......... one of the big plugs off of the fuel rail electronics............ i cant remember what else was unplugged and there wasnt even a plug on the harness .......... so i guess i made a bad choice with throwing in a 96 wire harness and computer is kinda what ur saying
im not very mechanically inclined ......... thought i would try ...... and i cant find a mx3 in over 100 km of me ..... im in ontario up near owensound

Your harness should have an extra plug for the second O2 sensor monitor but don't worry you don't need to use it. Your O2 sensors will be different and you definitely need the MAF or your car won't start. Go to Rockauto.com and compare part numbers for your components to see if 95-96 are the same or not. I doubt you need two temp sensors for your 96 I could be wrong but once again if there is no listing for a second temp sensor at Rockauto.com then you don't need to worry about it. I'm obviously not 4 banger savey,
http://www.rockauto.com/catalog/raframecatalog.php

EDIT; ok Rockauto dosen't seem to have much for the 96. I can't find half the stuff we're talking about. 95 has listings, problem is after 95 MX3s were scarce in the USA, they didn't even have the GS.

There are literally dozens of members near TO there. I suggest you post a [WTB] for a OBDI B6DE engine harness and ECM.

Why can't he simply stay with the OBD2. You did get the interface plug for under your dash right and as far as sensors go the only different one I know of is the O2 sensor but no biggy there. Your maf is also the same as the 95 so go on and just plug it in. Is it possible you didn't get all the harness from the 96?

I don't think its as simple as installing the OBDII scantool plug.

I tried to take everything I could see I was missing from the 96 in hopes it would all work .... Infect everything did work except the fan so I changed the fuel rail harness and wen I did that it kinda went all wack with the starting up of the car ..... It starts and dies right away then I start it again and it fires up flawlessly .... But still fan won't come on ...... I own a 96 in perfect shape and to me everything is just about the same just can't get this frigging fan to come on wen it needs to .... And the starting issue

Ryan wrote:I don't think its as simple as installing the OBDII scantool plug.

Tabernac, I was just gauging how much of the harness he actually had.

I have the whole engine harness ..... One from the computer one that connects to the battery and one for the fuel rail I have it all

And as for interface plug? U mean the diagnosis plug? It's under the hood behind the battery yes I got that

thats the OBDI one, the OBDII one is in the driver's side footwell.

The one from the 96 that i installed has the diagnostic plug under the hood as well

96 is guaranteed OBDII. 95 is not. Do you have the daignostic plug in the driver's side footwell?

My 96 has at the firewall of the drivers side under the hood right behind the battery