Finished my swap a few weeks ago and been having a cooling system problem. When I plug up my water temp sender and turn the ignition on the needle goes all the way past hot. The problem with that is the car will still be cold. I installed a aftermarket gauge and it reads and sits at 140 when cold. I went with a Microtech and I don't have a readin from my oil pressure gauge. Does any body have any ideal what would cause the readin to be so high. I disconnected the water temp sensor and the same reading is shown.

 

The water temp sensor for the gauge is on the rear iron (single wire sensor). The stock sensor for the ECU is on the back of the water pump housing (2 wire sensor).

 

Depends on what year car and what got swapped to what and what harness is being used on the engine (this harness is the EM harness in reality, the engine harness runs on the left side of the engine bay).

IF the water temp reads to the top with the wire off the sender on the left of the engine I'd pretty much guess you used a turbo EM harness on a non turbo car of the same series. Typical symptom of mismatched wires b/t the two turbo and non turbo EM harness.

 

Yes I did Hailers. I bought the engine and Microtech from the same guy who built the car. It was out of a 87 TII and I have a 88 vert. I've been trying to find out how to mod the TII harness to work correctly with the N/A. I did a Turbo swap earlier this year with a N/A harness and a JDM S5 engine and it blew due to lack of FCD. Shifted at 7600 (to clear carbon like I use to do in my N/A) and popped a apex seal in the front rotor is completely none existent. I've worked at dealerships so I'm not a noob. I completely disconnected the CTS (coolant temp sensor) ans I still get a reading which makes no since. I'm scared to drive cause I dont wanna blow my engine again.
The way they guy wired everything was using the stock harness intergrated into the Microtech MTX-8 harness.

 

I did alot more searching and found this post. https://www.rx7club.com/showthread.p...harness&page=2
All I can say is Hailers you are the man and thank you very much. now can you tell me why the oil pressure gauge is in-op? Thanks alot for the help!!!

 

I forgot I had responded to this post, so.......................the attached jpg shows the routing of the wires to the gauges from their source.

Look at the water temp gauge and follow the wires down the page. See where it shows two seperate plugs, one called FEM-01 for TURBO cars and FEM-02 for non turbo cars.

FEM-01 and FEM-01 are orange colored plugs that are a part of the harness connected to the engine (EM harness) that runs into the passengers foot well. So if you put a Turbo EM harness on the engine, the yellow/white wire for the water temperature gauge is in the wrong orange plug. You would need to put that yellow/white wire in the other orange plug so the signal would make its way into the non turbo Front harness that goes to the water temp gauge.

Meant to add.......the wire at the sender on the engines left side is yellow/white but when it enters the Front harness at the orange plug it turns to yellow/black (like the attached dwg shows).

I dont' know why your oil gauge does not work. The routing is the same for turbo or non turbo and all that wiring is on the left side of the engine bay and does not enter the EM harness at all or the orange colored plugs FEM-01/-02.

If you did not change ANY of the harness on the left side of the engine things should have worked. But I see you have a Micro tech so you might have done something to that harness that runs down the left side of the engine bay?????

What I wrote about the water temp wire runs above......make sense when you look at the attached jpgs?? Extract the Y/W wire from one orange plug and put it where it belongs in the other orange plug.

 

The attached jpg is out of the online 88 wiring diagrams. In the back of the book is the attached picture of the ENGINE harness on the left side of the engine bay and the items that are a part of that engine harness.

You can see a six socket plug on the engine harness (which will connect to a connector on the Front harness) and the Y/R wire in that plug comes from the water temp sender and if this plug gets connected back to the Front harness........then that signal will make it's way thru the front harness to the small meter harness to the gauge cluster.

That six socket plug is somewhere below the area of the brake booster/master cylinder area....sorta near the firewall but out front of it some. Down in that grundgy area of the engine bay.

If you put the turbo gauge cluster in the non turbo car that would make gauge read wrong/funny/not at all. I don't think you did. It's not a desirable thing to do.

 

I fixed the temp gauge wires lase night and going to do the boost sensor and a couple of more things to day. I wanted to say thank for the knowledge that confused the hell out of someone else, hit me like a ton of bricks with the pics of the connectors and/or the description of the plugs and wires/ slots/ sockets/ pins that the are...