i have a code of 1670 qdm 4 failure
van is a 1994 chevy lumina apv with v6 3.8 motor problem im haveing is van will allways strt but then sometimes stall out and when it does check engine light is on so if you turn key off and restrt it will then start and run no check engine light but while driving it sometimes it will stall and then you have to pull over put in park and restart then your good again for a while this happens all the time
if anyone knows what i should do or check please let me know im lost

Check basics first. Air, fuel, spark.
Start with verifying fuel pressure with a fuel pressure tester connected to the schrader valve on the fuel rail.

ok thanks

Would help to know what circuits that quad driver controlled....

https://www.gmforum.com/1992-1999-91...stions-287825/

This is a pretty extensive round with P1670 in a Bonneville. Looks to be A/C, Fan High/low, and MIL.

Given the symptoms, I would check charging system, chassis grounds, primary battery cables for corrosion, etc. It sounds like this case may lean towards a bad PCM.

I would also keep an eye on the temperature too, wouldn't want it to quit running fans while stopped and the temperature run away from you

Jesus, I remember that monstrosity.

Before my time, but I read it. Well the first few pages and the last two pages. Yeah what fun that looks like it was.

to change pcm do i just buy one and change it or does it have to be programed ?

It has to be programmed based off your VIN#.

This particular application has a prom that gets transferred from the old pcm to the new one.

If rockauto is to be believed, the PCM is interchangeable with all 94-95 GM 3.8s EXCEPT the 94-95 Buick Regal (frikkin yay :eyeroll: )