Good Day To All!

Here it is, 6 weeks later & I've got an update of the diagnosis. Well... An update that says nothing! But, I learned some interesting things along the way.

After I could not find any particular confirmation of which part was bad, I gave up & took my truck to a person I know who is reputed to be a very good diagnostician. He is willing to think out of the box. Once, some time ago- I had a lumina Van that would stall while driving. Multiple dealergyps & auto electric places could not find the cause. This man did. Van never messed up after that!

Initially, he thought it was, indeed, my truck's fuel pump giving up. He had it for almost 6 weeks and could not get it to act up. He made cold starts, hot starts, wet starts & dry. He drove it many, many miles, short & long trips- Many with pressure gauge and computer attached.

The next thing he did was to (very generously) call a friend of his and have my truck diagnosed by an engineering guru at the GM Tech Center. (Sometimes I suppose it pays to live in Detroit) Guess What? Absolutely nothing showed up as being a problem.

He pulled & cleaned several grounding points- hoping that a transient resistance caused the problem.

So far, I've had it back for a hundred miles or so and, perhaps, two dozen starts. No problems. I'm happy, but tentatively confident.

I did learn some interesting things in the process: I never knew that the security system has the ignition read the resistance of the key. If you buy a key cut from a blank made of the wrong metal, the truck will not start- fuel gets turned off. (No chip on this truck) Now I know why the bad guys carry blank keys when they are out grabbin & stealin'

There's another vehicle he mentioned that, if the wrong bulb is in the taillight, the transmission will not shift gears. Honest! I wish I could remember what car that was.

He told me of a bunch of other goofy interrelationships between components. I guess you really do have to 'think outside of the box' to diagnose a vehicle these days!

I sure appreciate all of the suggestions & help you all gave me. When the problem finally stays long enough to be diagnosed, I'll surely post the finding! (Wrong brand of washer fluid causing the computer to stop the flow of fuel?)

Thanks Again!
Paul

 

Nothing to contribute here, but it does sound like a fuel issue to me.

Anyways, I suppose I should get around to fixing that filler neck ground strap on my truck ... note even connected. hehe