88 TII w/ S5 JDM TII swap STILL wont run!
http://www.teamfc3s.org/main/factory...ual/1986_1988/
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From: Artesia NM
Ahh cool I was trying to decide if the FSM calls the ECU a CPU or if they were still refeeering to it as an Emissions control unit.
I have a starter switch or starter button hooked up under the hood so I dont have to get in the car to crank it. I had to unplug the lead to the starter to hook it up though. Gimme a minute I'll check for voltage at 3b and get back to you.
I have a starter switch or starter button hooked up under the hood so I dont have to get in the car to crank it. I had to unplug the lead to the starter to hook it up though. Gimme a minute I'll check for voltage at 3b and get back to you.
Ahh cool I was trying to decide if the FSM calls the ECU a CPU or if they were still refeeering to it as an Emissions control unit.
I have a starter switch or starter button hooked up under the hood so I dont have to get in the car to crank it. I had to unplug the lead to the starter to hook it up though. Gimme a minute I'll check for voltage at 3b and get back to you.
I have a starter switch or starter button hooked up under the hood so I dont have to get in the car to crank it. I had to unplug the lead to the starter to hook it up though. Gimme a minute I'll check for voltage at 3b and get back to you.
https://www.rx7club.com/2nd-generation-specific-1986-1992-17/86-tii-swap-wont-start-but-really-wants-887302/page7/
Top left wire------voltage w/key to start. (Black/Red or Black/White)
Top center--------voltage w/key to on. (Black/White)
Top right----------voltage w/ key to on with engine running or while starting. (Blue wire)
Bottom left-------constant ground. (Black wire)
Bottom right-----voltage w/key to on, but ground w/key to start. (Brown wire)
The Water Thermosensor (pin 2I) selects how much fuel the injectors dump into the engine at startup. If it's not working properly that would lead to either too much or too little fuel being injected. Also the BAC goes under full duty to help start the car as well.
Double Edit:
Cold start condition key to on 2 to 3 volts at pin 2I.
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From: Artesia NM
Ok its been a while since I put this engine in so my memory is a little foggy...
BAC=bypass air control and is mounted on the UIM over by the ABS pump and the shock tower?
If so then I removed it with the rest of the emissions gear and it is now blocked off.
Water thermo sensor seems likely since the fan on the A/C evaporator comes on randomly. I dont have a multi meter handy but I can pick mine up tomorrow afternoon and check it. Its on the water neck on the pass. side right? or am I thinking of my gsl-se?
BAC=bypass air control and is mounted on the UIM over by the ABS pump and the shock tower?
If so then I removed it with the rest of the emissions gear and it is now blocked off.
Water thermo sensor seems likely since the fan on the A/C evaporator comes on randomly. I dont have a multi meter handy but I can pick mine up tomorrow afternoon and check it. Its on the water neck on the pass. side right? or am I thinking of my gsl-se?
Ok its been a while since I put this engine in so my memory is a little foggy...
BAC=bypass air control and is mounted on the UIM over by the ABS pump and the shock tower?
If so then I removed it with the rest of the emissions gear and it is now blocked off.
Water thermo sensor seems likely since the fan on the A/C evaporator comes on randomly. I dont have a multi meter handy but I can pick mine up tomorrow afternoon and check it. Its on the water neck on the pass. side right? or am I thinking of my gsl-se?
BAC=bypass air control and is mounted on the UIM over by the ABS pump and the shock tower?
If so then I removed it with the rest of the emissions gear and it is now blocked off.
Water thermo sensor seems likely since the fan on the A/C evaporator comes on randomly. I dont have a multi meter handy but I can pick mine up tomorrow afternoon and check it. Its on the water neck on the pass. side right? or am I thinking of my gsl-se?
BAC pic in off red... https://www.rx7club.com/showthread.p...hlight=BAC+pic
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From: Artesia NM
Ooh I'll have to hunt one down both the ones I have are seized up and corroded all to ****. And I think I cut those wires back to the firewall but that should be easy to remedy. Uploading some pics gimme a sec.
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From: Artesia NM
Fuel layout:
Thermo sensor?
Unknown plug? its actually black but the glare makes it hard to tell:
Two more unknown plugs one is red with a yellow stripe and the other is black but connects to a yellow w/ red stripe wire that enters the harness next to the heavy ground lead:
Thermo sensor?
Unknown plug? its actually black but the glare makes it hard to tell:
Two more unknown plugs one is red with a yellow stripe and the other is black but connects to a yellow w/ red stripe wire that enters the harness next to the heavy ground lead:
Last edited by Texrx; Oct 19, 2010 at 02:18 AM. Reason: No images
89FC
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From: Bay Area, Cali.
Originally Posted by Google
Bypass Air Control Valve:
The BAC looks the same, but is in different locations between S4 and S5. The BAC valve is an ECU controlled device that allows metered air to bypass the throttle body, in effect, giving the ECU its own small gas pedal. The BAC is located on the driver's side of the dynamic chamber (DC) in S4s, and on the passenger side upper intake manifold (UIM) on S5s. Beyond providing an air bypass amount based on Crank angle Sensor (CAS) signals, throttle position, ignition switch, and boost sensor signals, the BAC's purpose is to stabilize idle when the engine sees various loads, like air conditioning, electrical loads, etc. During warmup, covering coolant temperatures above 59F and below 98.6F, the BAC valve, along with the air bypass solenoid valve below, contributes to a 3,000rpm idle for the first 17-seconds after cranking. The ECU controls the BAC based on the following signals:
S4 Bypass Air Control Signals
1. Boost sensor
2. Ignition coil: engine speed
3. Crank angle sensor (CAS): engine speed
4. Throttle position sensor (TPS): throttle valve opening angle (see [TPS Adjustment])
5. Water thermo sensor: engine coolant temperature
6. Water temperature switch: radiator temperature
7. Intake air temperature switch: intake air temperature
8. Ignition switch: cranking
9. Power steering switch: p/s active
10. Air conditioner relay: a/c active
11. Initial set switch: for maintenance*
S5 Bypass Air Control Signals
1. Intake Air Thermo Sensor (engine)
2. Throttle Sensor, full and narrow range: (see [TPS Adjustment])
3. Crank angle sensor (CAS)
4. P/S Switch
5. A/C Switch
6. Test Connector*
7. Blower Switch (part of electrical load control system)
8. Rear Defrost Switch (part of electrical load control system)
9. Headlight Switch (part of electrical load control system)
10. Fog Light Switch (part of electrical load control system)
11. M/T: Neutral Switch
12. M/T: Clutch Switch
13. A/T: Inhibitor Switch
14. Water Thermo Sensor
15. Ignition Switch
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From: Artesia NM
Hmm it still doesn't seem necessary to have the BAC especially since the only external loads on the engine have been removed or the s4 ECU is not tapped into (like the blower and rear defrost)
I also wonder if it wouldn't be possible to plumb in a needle valve in place of the BAC to manually control a metered air flow for starting etc? I happen to have such a valve somewhere if I can find it.
I also wonder if it wouldn't be possible to plumb in a needle valve in place of the BAC to manually control a metered air flow for starting etc? I happen to have such a valve somewhere if I can find it.
i wouldnt worry about the BAC, it is really only needed if you have A/C and shouldnt affect starting the car.. unless your idle set screw is backed out too much, but can be remedied with throttle pedal 
for just getting her started
for just getting her started
The pic where you question if it's the Water Thermosensor is accurate. The next pic of the slender plug appears to possibly be the oil sender plug. If the plug has a slot (open groove) on one of the long sides towards the end then it is likely for the oil sending unit.
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From: Artesia NM
Negative on OSU I have it hooked up already. Its just a blade type (female) connector in a black plastic clip. Lemme see if I can get a wire color. Can't remember what it was at the moment
Ok it appears to be green w/ black
Ok it appears to be green w/ black
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From: Artesia NM
Ok the unknown yellow and red wire in the last pics goes to the oil level sensor on the pan. More fun for its next oil change. That wouldn't effect starting would it? Could it just be grounded for the time being if it does?
Regarding the Black plug with the Green/Black wire, can it reach the sensor you mentioned that was located at the thermostat housing for the factory electric fan. That particular plug is Black and has a single G/B wire.
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From: Artesia NM
Maybe if I stripped it back outta the harness. I couldn't figure out what it was before so I just put it back when I rewrapped the engine harness. Its kinda foggy but I think it originally came outta the harness behind the alternator.
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From: Artesia NM
I got called off to work today so I didnt get much time to work on the car but I did get the intake back on and the lines run for the boost controller. I am still unsure if anything aside from the boost gauge should be hooked up after the throttles though. I'll be headed out to pick up my DVM tomorrow and some more vac line.