tsb 96-6e-101 PROM - Engine Spark Knock, Surge/High Cold Idle Speed

[nxk2000]

I'm working with a 1990 s-10 2.8 m/t. On a cold start it has a rough idle for the first minute or two then it will take itself to a fast idle till its warmed up then calm down to normal. Has anyone dealt with this tsb before? To me if you have a problem with the prom giving the computer wrong info it should be a problem that has always been there from when the truck was new. Not something that changes. Does anyone have some helpful info on this subject?
PROM - Engine Spark Knock, Surge/High Cold Idle Speed
BULLETIN NUMBER: 93-6E-101
SECTION: 6E Engine
NUMBER: 3
CORPORATE REFERENCE NUMBER: 336507
DATE: July 1993
SUBJECT:
ENGINE SPARK KNOCK, SURGE AND/OR HIGH COLD IDLE SPEED (NEW PROM)
MODELS:
1990-93 S TRUCKS W/2.8L (LL2) ENGINE AND MANUAL TRANSMISSION
CONDITION
Some owners of 1990-93 S-15 pickup trucks with a 2.8L eng: (RPO LL2) and manual transmission may comment that they encounter engine spark knock, surge, or high cold engine idle speed.
CAUSE
Engine system/component variability.
CORRECTION
If any of the subject conditions are found, then use the following procedure:
1. Perform diagnostic, per Section 6E of the Service Manual. Make any adjustments that are required, or replace any inoperative parts
2. If no other conditions are found using normal diagnostics, and this condition or conditions still exist, then replace the prom.

[BlazerLT]

Check your timing with the timing wire unattached from the PCM in the passenger compartment.

Sounds like you timing is advanced.