1995 GMC Jimmy Jimmy Hard To Start

Dear Bluelightnin6,

I want to place emphasis on the fact that Jumping it really does Start Engine first time everytime.
I have checked and volt-ohm metered the major Battery cables. All does appear fine with the cables.

Question : What is jumping the battery providing?
1. Higher battery voltage ( maybe 12.75 v to 14.0 v
difference)
2. Higher available Battery Current

A. In providing a higher voltage - this could be kicking an Engine element, Sensor, etc. Just over the approximate 12 volt threshold that iit needs to Start the Engine. (This could indicate that somewhere their is a component with a poor Ground or 12 volt wire connection? )
B. In providing Higher Current available - this could be kicking the components related to the Spark Plug Spark just over the threshold to start?
C. In providing Higher Current - this could be Spinning the Starter Faster, therefore the Engine spins faster on the Start Up, indicating that Engine Ignition Timing maybe critical? IF with the normal non-jump battery Current (I=E/R) available, the engine is spinning normal speed ( or slower ) on startup, therefore not nearly reaching the slight advanced Timing.
I think the Timing is set so slightly advanced that a couple degrees of timing is not going to make a difference. I need reassurance on these items.
Please feel free to comment on these items.

Looking forward to your suggestions.
Thank you

Bluelightnin6,

I appreciate your suggestions - helping along this path.
This has been a very difficult one for me.
I have not driven this car much siince we last commented here.
I purchased one of those cigarette lighter / power socket accessories voltage monitors. This way I can always have a exact in digital readout of the battery,
convenient in the cockpit.
When I turn the Key to ON position or accessory position the voltage at the cigarette lighter DROPS 1.5 - 2.0 Volts. I do not like this.
By pulling the Guage Fuse this lessens the voltage drop. By pulling only the ENG1 Fuse this really lessens the drop.
I want to know why ENG1 is pulling Much current.
I'm still pondering this one?
In the meantime I have been pulling ENG1 components off the circuit one at a time and plugging them back in. Still can't find this?

As of yesterday 5/25/09 - I installed a used Alternator from a 1994 GMC Jimmy or Blazer, can't remember or it wasn't that critical. It look like my Alternator !
WAYLA WAYLA - IT Started like one to two Times of Crank !
I Happier Now !
The voltage Drop is Less now when I turn key to On position - by about 1 volt !
I think this is related to the Voltage Regulator.
I had just installed a "new" Alternator (the least expensive) from Advanced Auto on 11/14/08.
My Starting problems started on 4/02/09.
Now, I want to rechange or purchase a new battery.
This morning 5/25/09 It took 5 times to Start.
A little of this is the EGR Valve I believe which I have the electrical connect temporary removed. Some maybe that I have change only 1/2 of the Spark Plugs to a hotter plug which I think you suggested.
I installed Z-Max Fuel and Oil Additives.
Yes, I agree this Engine is getting near Lifetime Age.
However, I would like to drive this car some or on a regular basis.
Please send a reply when convenient. I appreciate your help.