TunerPro User Forum

I suggest you "Update" your calibration or PROM and move to the 1989 Y-Car calibration. Many software and cal improvements. Then use the 89 Corvette/Camaro/Firebird ADX file. You have to place a 10k resistor across ALDL Pins A to B in order to receive the 8192 or fast data. Car will run be...

Hello, I did the Tech-1 communications for this car. We called it a "KEEP HAPPY" Messaging. This car has several controllers that communicate via the ALDL hi-spd link 8192. Each module has an ID and each module sends out it's message when Instructed to. If you "STEP" on these mes...

Hello, I worked for GM and at one point I worked on buy backs and then did the Tech-1., As I read this I remember this CAR. GM issued a PROM Update for spark knock OR Hot Fuel handling with a new Fuel Pump or something. Anyway when you used the TECH-1 or Tech-1A you had to TELL THE TECH-1 the CAR wa...

Please tell us what you are using for an ALDL Cable, PC, and have you installed the drivers from MOATES.NET? Do you desire to read the data stream at 160 baud or 8192 baud? The file looks to be a 160 baud. 8192 If I may make a comment, I see you have a 1987 Y-car. I would suggest you UPDATE the cali...

The GM 4T60-E trans did not have an internal transmission temperature sensor. A general rule for GM transmissions is: If the unit does not have a trans temp sensor it normally does not control line pressure via electronics. In the case of this unit line pressure is controlled via a vacuum modulator.

I tested the IAC input with a noid light. The noid light flashes with engine running. Lights turning red and green if throttle is varied. Noid light does not flash when key is turned to on position. Also no flashes when key is turned to off position. Noid lights stay lite but don't flash either in ...

Yes you can Override the ECM Commanded IAC via Mode 4. A Tech-1 or Tech-1A can over ride the commanded IAC via controlling the Idle Speed or IAC Position. This uses a Mode 4 string of command. I tried to issue a Mode 4 command in Tuner Pro but it didn't allow enough hex values to be written. I did a...

You asked how do I change the Parked IAC position? The PARKED POSITION is a CALIBRATION. A Standard Parked IAC position is 140 counts. In the 1980's and 90's TRUCKS were VERY SLOW to Decrement the IAC counts and so were SOME car lines. Like 3.8L and 2.8/3.1L because of all the Stalling complaints. I...

Hello n01tk, I won't waste funds on any O2 other than a Delco. I learned from my job the lessons of aftermarket O2's and saw this at home. I use a Denso O2 but recalibrate the tables. In the late 90's or early 2000's the big block released a bulliten for failing O2's.The Delco was replaced with a De...

Another Item to watch. Reman ECM's. I only use Delco. Had others trick me and ou find another ECM problem. Do it once and not twice.

Hello Nova Scotia, The small diameter distrubutor has problems as well. My won truck (1977 with a 454 / 4L80-E transplant) has a NEW GM Module, pick-up coil and silicone grease on the bottom of the moduel. I rean a ground strap to a stud I put in the dist base (extra I added) to providea level groun...

Hello, Low Voltage. I have run into a low voltage reading before. I learned early on to use a Quility Volt meter AND to ALWAYS sorce my GROUND TO THE BATTERY NEG TERMINAL. I saw a fellow tech measure ECM voltage at the ECM with the Ground of the DVOM connected to the ECM case on a GM. It read low. T...

I would highly suggest you either borrow a GM Service Manualor buy the diagnostic section. If I remember right Howell EFI in Michigan sells a book (gives them with the purchase of a wiring harness) for 20 or so bucks. I think it will diagnose your 93LT1. I have seen this so many times. Someone start...

OK. Now I would start at this point. Get a SCANTOOL that will read your data stream. Watch Engine RPM (Several eng rpm could be available within the data stream and could be sampled at different points in time ) SO LOOK AT ALL OF THE RPM reads and crank the engine. (I am taking it HAS spark as you i...

Hello N01tk, I did see (might have missed it) the engine in ur 1995 3500. If it's a 7.4L I believe the Fuel Pressure was higher that year for Hot Fuel Handling. (Vapor Lock). If i'ts a 5.7L don't get hung on the IAC. Let me get this straight. After 24 hrs you crank and it take a "Long" tim...

After you turned OFF the Enable VATS boxes, did you "Turn Off" the Trouble Code"? I Would also "Clear Codes" If you do not have Clear COdes, disconnect the Battery for a minute to reset the diag codes. When diagnosing this I would use a test lamp or NOID LAMP on one of the f...

what do you need still? let me know. I have a calibration file for this TCM. 1994 through 2002 GM 4L80-E stand alone. If you have a 1991-1993 TCM I cannot help you.