Pulling the intake on my '82

[wishuwerehere82]

It's your post on the Crossfire Injection Vault.

There Can't be two of you.:L Can there?

 

[jdp6000]

Got it now. All these sites look similar.

thanks for the help. I'll give this a try tomorrow.

Jim

 

[wishuwerehere82]

Good Luck!

 

[Twin_Turbo]

We put it in active mode and monitored the ECM and it is running open loop for most of the time. It went into closed loop once and smoothed right out, but a few seconds later it went back into open loop again and stayed there.
The readings we were getting were:
Prom # 9531
Temp= 195 degrees.
O2 went from .53V in closed loop to 0 Volts when in open loop.
O2 cross count=none 00V
IAC motors went from .17V in closed loop to .007V in open loop.
Map sensor= 10" HG at 1.44V in open loop.
Knock sensor= 0V in open loop.
TPS sensor= .56V in open loop.
Timing= 9.5 degrees in open loop.
The mixture alternated between rich and lean while we were monitoring it in open loop and most of the usual stumbling and oscillations were observed.
Needless to say, this was a real eye opening experience.
It seems to me that I have an intermittant open circuit on my O2 sensor somewhere or a bad new O2 sensor. My new sensor came with a new connector that I think I will splice in, in light of this new information.
Or a bad connection inside the ECM somewhere.
Any ideas? My brain hurts!

Pete.

What is active mode? You mean normal operating mode? The 82 ECM does spit out serial data in that mode, you should observer the parameters there and not in any other mode like special/limp mode, field service mode, backup mode or any other since certain parameters will be fixed and this will influence the system's operation.

So, read out the data with the test & ground leads not jumpered (wuth whatever resistor in place, the resistor values determine the mode, an open connection -> infinite resistance, is normal mode)

Then read out the BLM, the INT, the IAC POSITION! (not the voltage, it's a linear motor)

0V O2 in open loop is correct, if the sensor is not heated up the zirconia is not permeable for oxygen and it won't create it's own voltage (this sensor creates it's own voltage, that's why you never test it for resistance, it will be dead instantly)

TPS .56 is high, set it at .52 +/- 0,025V at 0 throttle (engine off, key on)

You can force the ECM into closed loop by inserting a 10K ohm resistor into A&B terminals on the ALDL.

The most common reason for sustained open loop running is the CTS being shot, the connectors corroded or the exhaust beign modified resulting in a cold O2 sensor. Did you install headers, removed the cat...something to that nature?

 

[wishuwerehere82]

Thanks TT,
The problem has been resolved since the first week in August and is running fine now. I'm even getting 24 MPG on highway trips now, with lots of power in reserve.
Can you give JDP6000 a hand? He's got the same issues now with idle speed, and is about to start replacing gaskets.

 

[Twin_Turbo]

where is his post??? don't see it

 

[wishuwerehere82]

It's On the Crossfire Injection Vault under "unknown problems" and titled " Idle problem"