A little history, The car was a LG4 converted to TPI. Have car running still needs a lot of tunning. The problem is The SES light is always on when the car is running but sets no codes. When I check the codes all I get is a code 12. I have check everything with the dist. but can't find anything wrong. So I need some more Ideas what I can check. Any ideas would be very helpful. I would like to solve this before I go much farther along with the tunning.

 

WELL ASSUMING THAT YOUR TPI IS RUNNING DECENT LIKE NO BUCKING, STUMBLING, OR POWERSURGE I NEED TO ASK YOU CAN YOU GIVE ANYMORE SYMPTOMS LIKE GAS MILEAGE IS POOR, CAR IS NOT RUNNING LEAN AND SMELLS RICH, AND SO ON BECAUSE THERE ARE A FEW SENSORS AND EGR CRAP IF STILL ON THE TPI WHICH WILL NOT THROW A HARD CODE ALL THE TIME LIKE YOUR O2 SENSOR WON,T BECAUSE THE ECM WILL AUTOMATICALLY BYPASS THE SIGNAL AND DETERMINE YOUR AIR FUEL RATIO FROM OTHER OPERATING SENSORS LIKE YOUR CTS. DID YOU TRY JUST DISCONNECTING YOUR GROUND TO THE BATTERY AND LET THE ECM SIT FOR A WHILE. THEN RECONNECT AND TAKE A SPIN AT ABOUT 60 MPH AND LET THE ECM RELEARN THE ENGINE. IF ALL ELSE FAIL I HAVE A 88 IROC-Z 5.7TPI AND STOOD WHERE YOU ARE SITTING NOW AND JUST TAKE IT SLOW AND REPLACE ALL YOUR SENSORS AND RELAYS ONE AT A TIME AND YOU WILL NOT BELIEVE HOW THESE ENGINES PERFORM REVIVED. MAKE SURE TO RESET THE ECM WITH EVERY CHANGE SO IT WILL RELEARN. HOPE IT HELPS TIM AND OW BY THE WAY SORRY ABOUT THE CAPS JUST REALIZED IT

 

What kind of chip are you running. When I started doing my own chips, the first few attempts would set the SES light but no code.

 

Just been getting the car running. I'am using the prominator. Did the same thing with moates adapter. Been running rich but with a stumble off the line. Been work on the rich problem. Is the SES light suppose to flash once the stay on till you start. Mine flash once the doesnt come back on till I start it.

 

It really sounds to me like you are in "limp" mode. When I had my problems with the first few chips I burned, it would start, but I had raw fuel coming out of the exhaust. Turns out, the Proms I was using, had to start at a certain hex, and until I figured that out, nothing I did to the chips would take effect. Since you are using a Prominator, I would check all your connections real well, and just make sure everything is installed correctly and that you are using the right code.

 

The SES should come on with the ignition and stay on until you start the engine. It definitely sounds like you have ECM or emulator issues of some sort.

 

Would a bad memcal cause this? It's about the only thing I haven't replaced. Thanks for the help.

Tad

 

Check the wiring to the SES light. IIRC, the LG4 used a "light driver module" and if you are running a 730 ecm (can't tell from sig) then the light is directly driven from the ECM.
The light driver module was usually located behind the dash and the internal board can be removed (if that is the culprit).
Just hit me when I read this cause I chased my down as one of the last items to rear its head when I did my conversion.
Just a thought.
Jp

 

I will look at that tonight. I think I know what mean I remeber something about that.

Tad

 

Hey JB found the board a remove it. Are there any wires I have to connect together?. I figure their is more then just removing the curcit board. thanks for the help.

Tad

 

No need to remove or jumper any wires. just take the board out and the circuits won't be fighting each other.
Did the light come on for two seconds then go off?
It should allow codes, etc if that was the problem.
If there was no light then maybe the wire was not run from the ecm when the TPI was rewired.
I don't know what ECMyou are using yet or bin.
That would help, I'm guessing you have a 730, SD setup.

 

Iam using a 730 and the bin is aujp. No light came on after removing the board.

 

My guess is that the wire from ECM "E7" is not installed when the swap was done. It outputs positive voltage to the light directly.
The light driver board from the old setup was a negative ground to turn the light on.
I don't know your situation on what was done during the swap but this must be changed.
What I did was take the E7 wire to ALDL pin " D" and connected it there behind the connector. That wire come from the secondary side of the light driver module and goes directly to the dash light.
It was alot easier than trying to find the dashboard connector and patch in there. (had mine all apart and still couldn't get to the connector good enough).
The ALDL pin D will indicate if you have a sevice light output on even if the light is burned out.
Pin "D" was on my Monte, double check that that is what the pin is on your car before connecting it.
Should be the same, but it's better to check a schematic.

 

Got it working right tonight. Just what to say thanks to JP86SS and everyone else that helped.

Thanks
Tad

 

Glad to help, good to see ya got it working.
Now that you can see your problems, be sure the data wire is connected from the ECM to pin E in the ALDL so you will be able to log data and find the errors.
You may not have that installed cause it needed to be added in the swap also.