Just wondering if there was some type of scanning software, that has wideband input capabilities? So you could see the AFR as a particular RPM, then put it parrallel to each other..Anybody know of something for OBD1 LT1's??

 

what is the output of the wideband? you would need a way to hook it to the laptop... if you can get it into the laptop i can get it into freescan.

 

Have any ideas?

 

The output on the wideband is 0-5v, linear.

Its an Innovate LM1, but I'm not completely familiar with a good way to input it to the PC besides the HPTuners interface I've used before. What about running it through an EGR signal wire? Will freescan read the signal correctly?

 

How about using the 0-5V wide-band signal by hooking it up where the oil temp sensor would go? I don't know which terminal it is, but you could probably look at a C4 PCM wiring diagram to see where it was hooked up. Some scanners will try and read the oil temp sensor on an F-Body LT1, and report "-40deg" since there is no sensor attached.

There are wideband controllers that will accept an RPM input signal, and allow you to record wide-band output simultaneously with engine RPM. The LM-1 does this, recording the wide-band output, plus 5 other channels.

 

As long as its designed to read a 0-5v signal, I don't see why it wouldn't work... The only reason I mentioned the EGR wire is I've read about a few guys with 98+ F-bodies doing something similar, but for different reasons. I know on the newer models the EGR uses that 0-5v range, so it SHOULD work. Even still, I would rather tap into an existing wire that isn't being used, than add a pin into a PCM plug. I learned the hard way the LT1 PCM's can be finicky, so I'd rather not take a chance of hurting its feelings again.

 

What sensor is there in the EGR system that provides a +5V output signal? Maybe the LS1 uses a feedback signal from the EGR for pintle position???? I know there are none on an LT1. The only EGR system interface to the LT1 PCM is the PCM output for the PWM EGR vacuum solenoid signal.

 

hmm... if there's that sort of discrepancy, maybe I just won't bother with the EGR idea. Its probably just as easy to reprogram one of the LM1 outputs to go 0-1v instead of 0-5v, then log it through one of the rear O2 connectors... OBDI did have a rear O2, right?

 

No.

 

hmm... okay... Thanks for all the info so far Fred, I do appreciate it.

What about the A/C Pressure? Surely they use one of those? And do we know what the voltage range for it is within the PCM?

 

If you do the oil temp spot i can read that relativly easy and change it and scale it to the wide band in freescan fairly easy

 

Whats the scaling on the wideband Fred?

 

Innovate products have a linear 0-5v output, barring any unforeseen ground offsets.

If I go that route, how exactly do you add a pin to those connectors? I've repinned connectors before, but nothing like the PCM harness style.

 

A wideband has to interface through a "wideband controller". Most controllers allow you to configure the output.... e.g. 10.0:1 = 0V, 20.0:1=5V, with linear interpolation. Here's a link to the Innovate LM1 sample configuration. I know the MoTeC Professional Lambda Meter offers similar output configuration options.

http://www.innovatemotorsports.com/r...ogOutTable.pdf

 

So the PCM is set to read the oil temp as 0-5v? don't temp sensors usually go off of ohms? regardless if you get it pinned up ill write up some code in freescan that matches with what fred posted ^ 0v = 10.0 - 5v=20.0