starting problem for 4.2
 

Hey Guys,

I have a major problem (or so i think) but i dont know where to start to do a diagnostic.

Where to begin with an explanation.

About a year ago my reverse on my trans. went out ( i posted many questions on this and dont ask how ive managed to get around without it - i just did - but i couldnt dish out the $4000 at the time to fix it regardless of everyone telling me i need to replace it) but the car drove fine in every other gear.

During the course of this time i did some upgrades on the car - mainly exhaust, k&n filter, and ECU upgrade (stage 1 for 91 octane rating).

Long story short, i drove the car pretty hard one day and then when i came home and tried to start the car again (2 hours later) it wouldn't start. It would crank but not turn over. I checked the basics i.e. fuel (it was pretty low) so i put a fuel cleaner in and then filled it halfway with plus. It started up fine and then i drove it for another hr or so but as i was coming home the gears were acting funny and the car started jerking a little ( in tiptronic when i shifted to fifth it kept going back to 4th) then all of a sudden the car shut down on me and i couldnt move it. now it wont start at all.

I bought a craftsman OBD II scanner to run a diagnostic but when i plugged it in it would say that it could not establish a link ( i checked it on another vehicle and it read DTC's no problem) so i have no way of knowing where to begin.

My main question is ( and i might be out on a limb here ) can running the car on regular for a while - which is what i was doing - and then switching back to plus cause problems for the ECU upgrade ( could this be a fuel pump/ fuel filter issue)? or does it sound like a complete transmission issue ( in which case i need to finally replace the damn thing) ?

Sorry for the long post but ANY help as to where to start would be greatly appreciated.