[rdlizard004]

It’s been so long since I’ve had it running I honestly don’t even remember which lights come on/stay on until start up…the problem is/has been: I bought the car with the original motor(USDM 91T) it ran drove fine and I bought a 3rd gen JDM 3sgte, but I was early in my automotive education so I sent both of the harnesses to a guy who said they would mate them to work…I think it was someone from this forum(but that was back in like 2007). Ever since then I’ve had issues, the main issue being that the car would start, run for about 15 sec and die and this fuse would keep blowing. Discovered that the stalling was due to the fuel pump resistor solenoid wire being disconnected, and now the fuse seems to be this red wire…

 

[GDII]

That would definitely explain the short run time with the resistor relay not being connected. The ECU runs 12v at start up and then back to 5V until you get on boost.

Ok so now I understand someone has gone through and made the harness for you. Only some minor things were changed but the red wire being joint up I think was to stop the oil level light going on. You don't need this as the JDM GEN3 3SGTE does not have an oil level sensor. If you get it running, ignore that light until you can remove it from the dashboard.

 

[rdlizard004]

That’s what I was thinking too except that it’s the oil pressure light, not the oil level light. I’m going see if it’ll start and run up to operating temp this weekend, then I’ll check to see if it’s throwing and codes again.

 

[GDII]

That’s what I was thinking too except that it’s the oil pressure light, not the oil level light. I’m going see if it’ll start and run up to operating temp this weekend, then I’ll check to see if it’s throwing and codes again.

The red wire seems to be the oil level light but the wire it was connected to is the oil pressure switch light.
Let me know how you get on.

 

[rdlizard004]

Just to see what would happen:!this morning I unplugged the oil pressure sensor and turned the ignition on and the low oil pressure light did not come on…plugged it back in and the light came on. I wonder if the sensor is bad?

 

[rdlizard004]

Update: I finally started the car today and it fired right up! Still no tach signal so I’ll need to test and see if there’s a bad connection or if the capacitors are bad…but the fuse isn’t popping and the low oil level light is on(so I’m guessing that that red wire is for that signal, I’ll just pull the bulb out of the cluster). I didn’t get a chance to run it for long but it seemed like it was starting to get a little doggy after idling for a while, so I don’t know if it just needs to be cleaned out or if it was running really rich and starting to foul the plugs…I’ll need to dig into it some more but this is progress for sure!!

 

[GDII]

Just to see what would happen:!this morning I unplugged the oil pressure sensor and turned the ignition on and the low oil pressure light did not come on…plugged it back in and the light came on. I wonder if the sensor is bad?

This is how it is meant to operate. The switch is spring loaded so when it has no oil pressure it closes and grounds through the engine completing the circuit turning on the light. When oil pressure is applied it pushes the switch open and the circuit is broken and the light turns off. It is on or off, no actual pressure readings will ever come from this sensor.

 

[rdlizard004]

Also discovered that my A/C pressure switch being disconnected is the reason that my radiator fans are on constantly…if I run a jumper wire there will the fans still turn on if it gets too hot?
…still working on the tach

 

[GDII]

Also discovered that my A/C pressure switch being disconnected is the reason that my radiator fans are on constantly…if I run a jumper wire there will the fans still turn on if it gets too hot?
…still working on the tach

The jumper connector is standard on the cars without AC. That should stop them running when not needed. Although can you confirm that both are running?
There are 2 fans in the front. One for AC, the other for the engine radiator. I'm not 100% sure on how the system works.

The tach things is really odd.
You should only need the wire to be fully connected from the igniter to the gauge. EA3 Pin 5, IE1 Pin 13 then plug A pin 3 for the 93 USDM. It's probably in a different plug and pin for the 91 USDM but I haven't checked.
Then making sure the gauge has power, ground and the capacitors are happy. I've not heard of other gauge circuit component failures.

 

[rdlizard004]

I only have the 2 oem radiator fans, I’ve removed all of the a/c components.

tracing wires for tach…

 

[GDII]

I only have the 2 oem radiator fans, I’ve removed all of the a/c components.

tracing wires for tach…

Ah yes. From my understanding the AC runs one of the 'radiator' fans and the radiator temp sensor runs the other one.

 

[rdlizard004]

All signs are pointing to the capacitors…I’ll order them today and update after I put them in.

 

[rdlizard004]

Got the tach out, so I’ll replace the capacitors…but there’s also this…?

 

[rdlizard004]

I think the capacitors are 10uf 25v…any idea about what the resistor is?

 

[GDII]

Got the tach out, so I’ll replace the capacitors…but there’s also this…?

Maybe that resistor or the connections are bad. The resistor is part of the needle control.

 

[rdlizard004]

I’m pretty sure that is a 6 k ohm resistor…but I can’t find one any where…I’m guessing that it won’t read correctly with one with a different value…

 

[rdlizard004]

I was reading it wrong, it’s a 16k ohm resistor…just ordered