Engine Harness Pin Removal
 

Good Afternoon,

After combing through a variety of emissions removal and de-pinning and engine swap threads I have a few questions I am a bit unsure of. The car is:

• a 1985 RX7 first gen with an S5 NA 13B being put in (track car)
• No emissions
• No dash stuff (it's all aftermarket)

1. Is the water pump temp sensor used by the ECU for anything, or is this just a warning light or emissions related?
2. What is pressure sensor (Connector B-33/Pin 2H) used for?
3. Can someone confirm or contradict with emissions removed looks like I can remove (pictures say it more clearly but my text summary below)
   • B1-16 (3J) Solenoid Valve Accelerated Warm Up System
   • B1-17 (3I) Split Air Solenoid
   • B1-18 (3Q) Bypass Air Control Solenoid
   • B1-19 (3M) Pressure Regulator Control Solenoid
   • B1-20 (3A) Solenoid Valve (6port injection system)
   • B1-23 (2N) Solenoid Valve (Port Air)
   • B1-24 (2M) Solenoid Valve VDEIC
   • B1-25 (2O) Solenoid Valve Switch
   • B1-27 (2P) Solenoid Valve Relief
   • B1-28 (1P) Heat Hazard Sensor
   • Picture Legend - green keep, red delete, yellow optional and ? I am asking.

Hope this makes sense. I could only find snippets of this in the 1st gen forum but I imagine a bunch of 2nd gen folks have cleaned up their harnesses.

Thanks in advance.

Jessehttps://cimg0.ibsrv.net/gimg/www.rx7...995e1817ca.pnghttps://cimg1.ibsrv.net/gimg/www.rx7...3cea41d42a.png

I'm pretty sure the ECU uses this sensor to determine engine temps and bases its fuel delivery accordingly(cold start, open/closed loop etc) while the one on the side of the engine is for the dash temp gauge. The ECU should still run the engine with this gone but I don't think there would be any advantage to eliminating it while having several drawbacks.

Cool thanks. We are having to run a different water pump so was seeing if we needed to make the adaptors for the sensor or just plug the hole.

Thanks
Jesse

As Mlammert said, the temp sensor behind the water pump is used by the ECU. I would assume you would have to run everything relevant to the engine. S5 is OBD so it possible you may throw some codes if some things are left disconnected without an ECU flash. I could be wrong though. After you finish the harness, but before you wrap it up, I'd give it a test run to make sure everything is running ok in case you need to add more wires.

Oh yeah, being S5 might make things worse with the limp modes the ECU can use. I think disconnecting the electronic OMP can cause limp mode too. On my early S4 I don't think they had those since I've tried it out and ran the car with it disconnected to see what would happen to my AFRs, pretty sure the S4 just defaults to a base fuel map. Definitely use the ECU temp sensor, no reason not to for either S4 or S5.

S4 had a mechanical OMP.

Disconnecting the S5 OMP is the only thing that will put your S5 in limp mode.

Yep, that I do know. Its on the list of "stuff to keep"

More of the questions were on the

• temp sensor (answered - thanks all),
• the pressure sensor (B-33/2H)
• and if the listed solenoids are good to remove as they should just be for emissions stuff which has all been pulled off.

Jesse

What I meant was the ONLY thing that will put your ECU in limp mode is disconnecting the OMP on an S5. Disconnecting other sensors may throw a CEL, but wont activate limp mode.