JDMZ28

iTrader: (1)

First off let me say I'm very familiar with the OBDII tuning and have tuned many cars before.


My dad has a 91 Z28 convertible. It has a 305 TPI, automatic.

I have a laptop. I know I need a 12 pin connector and some scanning software. But, I want to be sure before I start buying stuff.

Since this car uses a prom I won't be tuning it just yet, just scanning. Are there any free scanning programs that will work with this ECM? Will datamaster work? Here is the cable I was thinking about buying. Are there any cheaper ones I should consider?

http://www.aldlcable.com/

Blue-Z28

All you need is a paper clip.

http://sethirdgen.org/dtc.htm

RBob

iTrader: (1)

Datamaster works, although not free. Has a 30 day trial period.

TunerProRT works, is basically free (donation requested).

RBob.

JDMZ28

iTrader: (1)

by scanning I don't mean reading codes....otherwise I'd just got to autozone. I want to see what all his sensors or doing because it intermittenly feels like it's running on 4 cylinders and has jerky acceleration. I have datamaster and I think I have the unlock code somewhere.

I found the tuner pro, is there anything else I need besides the cable I posted the link to? I know some of this older stuff can be tricky, are there any tricks I need to know about?

RBob

iTrader: (1)

No 10K resistor across A&B of the ALDL port. Leave them open.

RBob.

JDMZ28

iTrader: (1)

I'm sorry but why do I need to run a 10 k resistor across terminals A&B?

RBob

iTrader: (1)

On a '91, no 10K across A&B. Not required. Note that you will find cables with it built in. So make sure that either it doesn't, or that there is a switch to turn it off.

Using a 10K across A&B changes the operation of the ECM.

RBob.

JDMZ28

iTrader: (1)

you must excuse my ignorance. But what's the purpose of changing the operation of the ECM? Like I said I'm use to the OBDII stuff, oh and I also tuned my 95 T/A as well.

I'm just looking to "real time" scan his computer so I can see what his sensors are doing in real time. Will this cable work fine for the 91?

http://www.aldlcable.com/sc/details.asp?item=aldlobd1u

again, I'm not just trying to scan codes. I figure this cable + tunerpro should be good for what I'm trying to do?

JDMZ28

iTrader: (1)

I see here, found on aldl's website.

Some older cars (such as early TPI's like GM 1227165 ECM, 1986-89 5.0 and 5.7 V8's) will require a 10Kohm resistor to be plugged in between pins A and B on the 12 pin ALDL connector in order to put the car into "ALDL mode" and have the serial data start flowing. We provide a 10Kohm resistor with our cable.