92 Buick Century 3300 stalling, can't connect.

[Jarod]

Hello Everyone.

I'm very new to all of this type of stuff (My car is 100% mechanical injection diesel with no computers anywhere, and very little electrical)

however my wifes 92 buick century is much more complicated.
It stalls randomly when idling especially after its warmed up to operating temp.

I've tested the Crank sensor, replaced the IAC, Coil packs, ICM, all 6 injectors, the fuel filter and it still randomly stalls. Cleaned the MAF.

same exact thing with o2 sensor unplugged, as well as maf and TPS. nothing seems to make a difference. there is no EGR that I can see.

usually it will restart, sometimes you have to hold your foot down on the throttle pedal a bit but it starts back up and runs fine for another 3 or so minutes then stalls again.

I'm out of ideas for where to go next, I knew newer cars have OBD2, and my brother has scantools for that, but this car has OBD1. I've never dealt with it beyond the paperclip to read codes. and thats another thing. the car never sets a code. for anything. sensors unplugged, nada. no check engine. and if it ever comes on then cycling the key turns it back off.

We were driving up a rough road when this all started and I haven't been able to get it running consistantly. so it sits in our driveway...

Anyways, thats my essay on the problem with the car, Heres what I really need to know I guess.

I have a USB to TTL adapter I believe will work as a ALDL cable.

Connect to the RX pin of my adapter to the pin below Pin A I think is right?

But I have been unable to find much information on connecting to the car. I know OBD2 is standardised, if you can connect to one you can connect to all of them (only exception could be CAN) but obd1 seems that I need definitions for tunerpro or something like that but I can't find a lot of info on which one i need.

It also seems like tunerpro only will show the datastream if I purchase the program from what the help file says. is there another program I can use to see the datastream? I'm not sure if the ECM in this car can be connected to at all, it was apparently replaced about a year or 2 before we got married (about 4ish years now I think) and it looks like an aftermarket unit, they has to use adapters to hook it to the wiring harness. (probably why the computer won't store codes anymore)

Hope I haven't bored you with too much garbage info!
Thanks!

[robertisaar]

don't suppose you can see any markings on this potentially aftermarket ECM? or perhaps some pictures?

and no, you don't need to register the program to get the datastream flowing.

assuming you have the factory ECM still, this car uses a LG7, which from this page:

http://www.tunerpro.net/gmOBDI.htm

means you'll need the A143 file. you can directly use it in tunerpro RT V4 or with some slight tweaking, use it in tunerpro RT V5.