Attached is a copy of my LT1 Scanning Guide. This document was originally written 20 years ago to help the owners of the ScanMasterLT1. It has been revised to delete superfluous info for the ScanMaster.

I get requests for copies from time-to-time, and have posted it previously, but decided to put it on this forum as a "sticky".

For comments, corrections, questions, etc., please send me a Private Message.

 

PEOPLE COME HERE, APPARENTLY EXPECTING A SIMPLE, ONE SENTENCE DIAGNOSIS - e.g. - "It's the fuel injector on cylinder #5." UNFORTUNATELY, IT DOESNT WORK THAT WAY. They appear to lose interest when I ask for more info about modifications, or when I ask them to run the log over, per the guidelines below. They refuse to do the simple diagnostics I tell them that need to be done.

And in all honestly, I am not always successful in finding the problem.

When I do make a suggestion of where I think the problem is, they seldom come back with follow up, leaving me with no idea whether the time I invested helped them or not. Hopefully, someone else will volunteer to provide this service in the future. So far, no volunteers.

DATA LOG GUIDELINES

Do not reset PCM. Do not remove a battery cable. Do not pull the PCM BAT fuse.

Start COLD engine. Do NOT turn on A/C or Defrost. Turn off traction control (ASR / TCS) if vehicle equipped.

Leave the accel pedal alone. Do NOT rev the engine while it is warming up. Don't drive it. Leave it alone.

Allow engine to idle for at least 4 minutes. Should be long enough to warm up and put PCM in closed loop.

Start driving car for about 5-10 minutes. Vary the accel pedal position and RPM. Make at least one WOT pull from a roll up to at least 5,000 RPM.

Mentally note (or have a passenger write down)when the engine exhibited the problem you are chasing.

Stop driving, let it idle for about 30 seconds, without touching the accel pedal.

Finished.

Post your .csv format log as an attachment to a post in the active thread addressing your problem. Do not upload it to a 3rd party site.