An error code usually means a poor connection is involved, thus replacing an item will usually not solve the problem in this case. You need to look at the TPS plug and clean it up and make sure the connection is a solid one and look at how the TPS wires plug into the ECU as one of them might be pulled back within the ECU plug. And it's best to take TPS measurements at the ECU and not the plug itself.

 

Error code 25 being the PRCV. Plug has but two wires. B/W reads 12 volts w/key to on. The Blue/Orange wire reads less than 2 volts w/key to on. Idling (first 20 seconds) less than 2 volts and after 90 seconds of idling the voltage reads 12 volts. Pin 3M of the ECU is for the Blue/Orange wire and again, best to take the measurements from the ECU.

 

I will go check the connections at the ground and I set the new TPS via resistance measurements to 1k ohms at rest and watched as it went to 5k. At the very least, I have eliminated that variable. I will check the connections again,

I honestly do not know if the PRCV is still on the car. Many things were randomly removed from this car.

Took the car for a quick test drive and now I threw a solid code 5 (knock sensor). So, I shall check that now as well.

Thanks again Satch and Happy Thanksgiving!

 

When setting the TPS via the ohm method the TPS is unplugged so that doesn't mean the ECU is receiving the proper signal. The signal at the ECU (Green/Red wire) should be relatively close to 1 volt w/key to on after the car has been completely warmed up.

 

Checked that via the ECU connection, everything measured out correctly.

I took another look at the hacked up ecu wires. This is what I found:

This is assuming that I am reading the pins properly. These would be from left to right facing the ecu unit.

Pins:
3A is grounded (supposed to be ground, maybe added another ground just to be safe?)
3B is grounded (supposed to be ground, maybe added another ground just to be safe?)
2C is grounded
2B is grounded

Also, what color plug is PRCV? I cannot locate it in the FSM or via Search


This is 2c and 2b.

 

Looking at the back of the ECU plug, the top right pin position would be 3A.

 

After re-checking the pins, it seems that the following are grounded.
3g
3e - these seem to be spliced into a common ground that runs up into the harness (it almost looks factory)
3h


3a
3b

I am starting to think that the CEL 12 has to be related to the connection at the plug. The plug and tps connector seem to be just a little too short, thus making it kind of a tight fight to get them connected. This could result in a loss of contact when the motor moves under acceleration. I will test this tomorrow with a friend holding them together closer, and if it seems to be the problem I will lengthen the TPS harness wires.

I need to check for vacuum leaks more thoroughly as well.

 

Update: Extended the tps wires in hopes that it would solve the intermittent issue. No luck. Tested for vacuum leaks and didn't find any. It does seem like the car is running extremely rich though as we sprayed starter fluid into the intake and it stumbled a bit.

 

Well I took off the UIM and looked around. Everything was routed correctly and I replaced some vacuum hose as I went.

The weird thing is that when I swap out ECU's, my original ecu only doesn't flash any code. The ECU I borrowed flashes code 12 and 25.

However, both still hit have the CEL come on under throttle and disappear after. I am going to reset the TPS again at the ECU.

 

You really need an analog meter to test the sweep accurately.

 

I feel stupid for not trying this earlier. I unplugged the tps with the car running and all the issues went away. I am assuming there is a short in the wiring from the tps to the ecu, and I will be tearing into that tomorrow.

 

Post #8 in a thread w/more than 8 posts never fails. It never does.

 

You need to check the TPS via that three pin green plug near the passenger side strut tower. 2nd Gen TPS Adjustment

 

And one more time with feeling. You cannot accurately test the sweep of the TPS w/a digital meter. This applies to everyone including yourself.

 

I will be using an analog meter. It is hard to believe that the new sensor I bought is bad as well.

 

It might not be the sensor but to test it properly and go from there is the better course of action. And what do you by new? Out of the box new or out of someone else's car?

 

As in brand spanking new. Put it in and it didn't change anything. This leads me to think that there is a short or some wire not properly connected. The pins at the ecu seemed fine though.

Took it for a short drive with the tps unplugged. For the most part, it drove much better.

 

When the TPS is unplugged the ECU defaults to full throttle condition. Did you set the new TPS after install?

 

I set the new tps after and still no dice.

 

Checked voltages at the ecu for the tps pins and all of the signals check out fine for appropriate voltage.

 

So I have been slacking lately on figuring this out. I discovered that the "new" TPS I purchased was defective from the factory ( would not adjust close to the FSM specs) and promptly had a new one shipped out to me.

So here is the deal:
Installed new new tps, and set it to the proper specs via the FSM. Car runs fine for about a minute and then goes all whacky. Sometimes the throttle bounces, sometimes it sticks at 3k or some other random RPM. I was told the motor was not streetported, but it sure idles like it is.

What else could be causing this? I have know it is a TPS related problem but I have checked and eliminated all the common suspects.

 

How does the 3K rpm idle speed occur? Do you have to increase the throttle to that level and it sticks there or does it just rise to that level from a normal level by itself?

 

Seems stupid I know.. But is there slack in the throttle cable?

 

There is slack in the throttle cable so tension would not be the issue. If I press the accelerator, it will sometimes stick at 3, then slowly go down, back up, or whatever the hell it wants to do. Still has a lumpy idle and has a hesitation or miss somewhere. I checked the coils by swapping them with known working units off my other rx7 and that made no difference.

Once again, if I unplug the tps the car runs a little better.

 

How were you able to determine that the previous new TPS was no good?

W/the new TPS do you still get an error code?