Chevy86 IROC-Z

iTrader: (17)

Sup guys. Question. What will happen if I drive with with the A & B terminals grounded while data logging? I made a homemade ALDL Cable along with a 10k resistor in between A & B as instructed in the schematics. But doing just that disables the knock count. So if I connect A & B while data logging without the resister, I know the ses light will flash. But will I cause harm to my IROC?

Chevy86 IROC-Z

iTrader: (17)

Here is the link to the schematics.... I built the first picture.
http://winaldl.joby.se/aldlcable.htm

Da Spudro

i can't answer for certain about damage, but my old 91 Z28 used to have weird inconsistant running issues. i figured out one day that if the car kept stalling on me plugging my code reader into the ALDL and turning the car on would cause the Check Engine light to flash like it was trying to give me a seizure, but the car would actually run, and run better then it had been running. i'd turn it off after about 30 second and it would be like it gave the car a swift kick in the **** and it would run fine for weeks afterward. - i did this by accident by the way, because i had the fear of whatever god put in me that doing this was bad, so i freaked out when i did it.

Chevy86 IROC-Z

iTrader: (17)

Strange. So now your Camaro is fine?

Da Spudro

In a manner of speaking.

it developed a problem with idle and the fuel pump overheating causing problems with power loss and leaving me stranded for a few hours. i spent about a year and a half and a butt-ton of cash replacing stuff that never resolved the issue. combine these issues, with frustration of people constantly hitting the car, never having the money to fix anything with it, some body alignment issues, and me buying my Vert.... sadly i gave up on it and sold it. - which is a pity considering i do miss the car, but the new owner has spent a bunch of time and money fixing the issues i could never seem to get money for and has slowly been bringing the car back to life again. he still hasn't fixed the idle, or fuel pump overheating issue, but supposedly it runs great for him. i think that is partially because they never drove it when it was running good so they don't know the difference.

before i had all those issues and sold it whenever it started acting up i ran it with the code reader in and it seemed to fix it for a while.

xch3no2

Have you tried starting the session w/ 10k in place then removing it?

Da Spudro was forcing open loop for driveability.

ALDL mode usually increases idle, some take a different timing set.

I don't see it hurting your car, long term open loop may run richer, cats might not last as long.

Chevy86 IROC-Z

iTrader: (17)

Hey xch3no2, my apologies if I offended you on the other thread. I've only ran the data logging with the 10k in place. But if I run the data logging with a solid wire across a and b, won't the iac valve close all the way, thus changing the MAF sensors air measurement? I also have no cats installed. I'm just worried that I'll destroy something by driving in "diagnostic mode" with a wire in the Data terminal.

87IROC420

is there aldl cables for sale with 10k switches . just plug in and go

red rock

iTrader: (2)

This one has the resistor already on it. http://www.aldlcable.com/sc/details.asp?item=aldlobd1u

87IROC420

ok but i thought you had to take the resistor out after you start getting a signal . will this one work

red rock

iTrader: (2)

No, you don't have to take the resistor off after you get signal. But if you want to remove or change the resistor setting for other ECM's, this one is capable. Just remove the little clip from the pins. The risistor pins are on the USB plug. (you can see it in the picture) Here is the instructions that come with it. http://www.aldlcable.com/aldl-USBinstructions.pdf

87IROC420

so this wont affect the ECM mode and make it run at high idle or anything like that

Tuned Performance

iTrader: (92)

You won't be able to initiate logging at 8192 on the 165 without the 10k resistance applied between pins A and B. Data should flow through pin M or E. Once communications are established, the 10k can be de-exerted. However, it will be needed again if communication is lost or ECM power is cycled (keyoff).

Winaldl requires the 10k resister to be kept in at all time but tunerpro does not. When the 10k resister is installed and the engine is running there is a rpm and spark adder.



https://www.thirdgen.org/forums/dfi-...-tunerpro.html

ASE doc

In the factory ECM, shorting terminals A&B, with the engine running, places the system in "diagnostic road test" mode where the CEL flashes 2.5 times per second in open loop and 1 time per second in closed loop. The closed loop timer is bypassed so that the system reaches closed loop sooner and the CEL on time/off time indicates rich or lean fuel trim.

This wont damage the ECM, it just isn't useful for reading codes and since we can't see data without a scan tool, this mode is of limited value.

87IROC420

im getting high knock retard on my datamaster . i start with 10k resistor in place then take it out when it starts to read