I know that there is a simple test for checking the Throttle Position Sensor. I haven't gotten off my lazy butt to do the test yet.

Here is my problem:

I had a '43' engine code, so I replaced the knock sensor.

Now, my car idles rough, surging up and down, (cold or warmed up), and tries to die, while idling.

With the TPS unplugged, it won't surge up and down, but it will still run rough, only at higher RPMs.

I didn't get an engine code for the TPS. I just figured that since the engine was not able to maintain a steady idle, that the TPS may be at fault.

Since the only code I had was a '43', and replacing the knock sensor didn't solve the problem, could the ESC module be the problem? Or do I have to drive around for awhile for the engine to adjust to the new knock sensor?

Prior to installing the knock sensor, the engine idled smoothly, no problem.

After installing the knock sensor, I have no engine codes.

1985 Coupe, automatic

 

Did you properly torque the knock sensor?

 

Don't own a torque wrench. Didn't torque it.

How long would it take for the engine to set another code '43' if the problem was because I didn't torque it?

At this point, I still don't have any codes.

 

I'm still learning about the OBDI vehicles( I went from carb's to OBDII). But I would assume immediately, considering it is real time information. Once it sees a fault it trips the CEL.

 

I appreciate the help. When I figure it out, I'll post it here so everyelse will know, too.

Thanks, again.

 

It won't set a code from improper torque (unless you broke it). If you don't have a torque wrench a good place to start is to run the sensor in by hand until it is tight, then using a wrench turn it about 1/8th turn more.
The TPS won't always set a code when it goes bad.

 

Sorry, I didnt read the part about it setting a code because of improper torque.
As Morley said it wont. It can & will read false knock. Then retard the timing. The knock sensor operates on frequency & if the sensor isnt torqued properly, the frequency readings will be off.
This is about the easiest way for me to explain how it works.

 

Unplugging the TPS with engine running should set a Code 22 - that's a basic ECM test - unplug it and verify that the Code is set.

You might want to unplug the MAF. The ECM will then use a fix value for airflow and if everything smooths out, you need a new MAF.

The only thing I can think of that you may have done during replacement is open the ground from the ESC module to the engine or that there is some sort of wiring problem. If so, you may not get a 43, though I doubt that it would cause an idle problem. Basic test is to rap on the side of the block with a suitable hammer while monitoring knock with a scanner. If the knock signal is indicated, the system is working. Of course there should never be a knock signal at idle/no load. If the scanner indicates such, then you will have to re-troubleshoot as that condition would also prevent it from setting a 43. Again much easier with a scanner - disconnecting the knock sensor should indicate no knock, if it does, and there was knock with it hooked up, the sensor or wiring is bad. Or, if a knock is indicated with the Sensor disconnected, Module is bad.

 

try the fuel regulator. Unplug it and see if it spits out gas.

 

Also, make sure the sensor contacts are free of grease, grime and oil. Also, DO NOT use thread compound on the sensors as it can adversely impact its acoustic capabilties.

The orange coating that comes on the factory sensors is all you need. The correct torque is 15 lbs., I believe, but check your service manual to be sure.