Plain Jane OEM nothing to see here rebuild

[JustJeff]

I've got the throttle thing sorted out. The throttle cable had too much slack on it.

My new problem is timing and fouling of plugs. My trailing timing does not line up. leading is dead on. Engine warmed up, RPMs around 750ish. TPS set to 1V in idle position. But trailing timing is advanced just about halfway between the leading and trailing marks.

I went through my ECU pins looking at voltage. I found a couple of oddities:

1) Clutch switch on the front of the clutch pedal was dead. I replaced that and confirmed the ECU is seeing a signal from it.

2) AC relay and A/C switch both show 12V whether A/C switch is on or off

3) Neutral switch shows no change at ECU between Neutral and in gear...but IIRC I do not have a neutral switch on my JDM transmission.

4) Oxygen sensor was way off, but that might be because my engine is running really rich??

It's supposed to be Idle-below 1V, Accel -.5-1V, Decel -0-.4V.

Mine idled at 29.6mV, I wasn't driving with DMM on, but I throttled the pedal Accel-22mV, Decel-26mV

5) The other oddity was my TPS narrow at first seemed to be dead. Even though it showed 1V at the sensor and shows a clean sweep. At the ECU it showed very badly 2.64V and never really changed much as the throttle changed. Before writing off my TPS I checked it again another day and it read dead on that time. I checked it at the sensor first. Then checked it at the ECU and it had the same reading....very strange. It might not have been backprobed correctly the first time, but I thought I checked it and double checked it.

6) Full range on the TPS is definitely off by a bit. It should read .8V at idle and mine sits at .54V. Can I get some feedback on that one? On the one hand off by .26V doesn't seem bad, BUT that is a significant amount when it's 1.4 of the total spec reading.

I have an Innovate wideband on it's way to me. I'm hoping to have it installed this weekend.

[RETed]

Originally Posted by JustJeff

1) Clutch switch on the front of the clutch pedal was dead. I replaced that and confirmed the ECU is seeing a signal from it.

When mines went bad, the engine tended to idle slightly higher than normal.

2) AC relay and A/C switch both show 12V whether A/C switch is on or off

I believe the circuit pulls to ground - the switch grounds out at the A/C compressor?
Also, I believe there's a pressure sensor switch (for safety reasons) is wired in series to the circuit...which could be the culprit?

3) Neutral switch shows no change at ECU between Neutral and in gear...but IIRC I do not have a neutral switch on my JDM transmission.

I know this affects the cold-start idle on initial cranking...

4) Oxygen sensor was way off, but that might be because my engine is running really rich??

It's supposed to be Idle-below 1V, Accel -.5-1V, Decel -0-.4V.

Mine idled at 29.6mV, I wasn't driving with DMM on, but I throttled the pedal Accel-22mV, Decel-26mV

This is odd, but it should not affect anything outside of slightly worse gas mileage...
It should see at least 0.5VDC at idle and decent acceleration.

6) Full range on the TPS is definitely off by a bit. It should read .8V at idle and mine sits at .54V. Can I get some feedback on that one? On the one hand off by .26V doesn't seem bad, BUT that is a significant amount when it's 1.4 of the total spec reading.

This might trigger one of those nasty E-OMP error codes which could trigger limp-home mode...


-Ted