Spring may be broken. Try pulling the handle and at the same time pull up on the parking brake pedal. If it come up and releases, the spring is broken.
? 7:28
https://www.youtube.com/watch?v=PBx2MgVy1V0
Dec 24, 2012 - Uploaded by WhoSaidTyler
I have been told they have a kit for that oil pump which consists of a spacer ring and larger oil pump .... Will ...
? 1:49
https://www.youtube.com/watch?v=gsAMtuTbE5U
Mar 6, 2012 - Uploaded by MET-TECH LLC
New main bearings, rod bearings, camshaft bearings, piston rings, head gaskets, ... oil pan gasket, oil pump ...
? 3:22
https://www.youtube.com/watch?v=SGCg1KHi2NU
Oct 12, 2012 - Uploaded by seriousNoodle
It turned out to be a loose piston and unbalanced torque converter. ... Stats on Engine: 3.8L V6, GM VIN Code ...
You will really need a body manual for that specific vehicle to do type of work. You can buy it from GM. You can even buy it online from GM. // Really, if you try to guess at where the "pull" areas are (even if someone can tell you where they are), and/or what sections need a tool type puller... etc, etc, etc... you can do some serious damage to that _very_ fragile panel. It's the type of thing that can possibly be easy enough with the correct instructions and correct tools; while also being the type of thing you regret touching without such information. (In the "old days" you could have experimented on one in a junk yard, but those days are gone).
The easiest route would be to replace the pcm with a used one. The quad driver circuits are inside the unit. Somebody trained at computer repair could do it, no problem. But just buy a used one for a few bucks, transfer your mem-cal packet (memory and calibration) into it, install it and you are ready to go again.
Before you take out your old one from under the dash passenger side, be sure and take off the negative battery cable from the battery. Never unplug or plug in any connections to the pcm when the battery is on line. Damage may result.
check for a faulty wire/s to the tacho of a faulty tacho unit
the tacho gets its reading by the ignition impulses so any engine running problems may have been a result of the faulty tacho or wires.
YOU NEED TO SEE A TRANSMISSION MAN, THIS DOES NOT SEEM TO BE A JOB AN END USER CAN TACKLE. aLMOST CERTAINLY GEARBOX TROUBLE I am afraid
Good Luck with it
