Sometimes problems just are not as easy as we would like....I changed my Avatar to more accurately reflect how I feel and look, regarding try to figure out why my truck was intermittently shutting down....sometimes you gotta walk away and clear your head......that said, I am still a little gun-shy as I have it running and ran to the store, but still nervous....lol

Long story, short...so far,

Fuel supply or pressure: Lift pump was a weep hole leaker and I could only assume it had 207xxx miles on it, so I checked with my gauge and she was slow to rise and only hit 30 psi...so I r & R'd her....50-60 psi bouncing, no BB.

truck started and idled, but would die if I loaded up the engine by putting on the A/C!? hick-up, catch itself.....
so I scanned with A/E

Changed out CPS with a IH CPS p/n 1876735C91.....so far, seems alot more stable than the old CPS.

Old CPS, seemed it was slow or erratic to get the pressure built up for PCM/IDM start sequence. I can only guess that during driving and different loads on the engine, the CPS would act up and help kill the engine / sensor sequence? ...NO Codes or the CEL would ever illuminate. Also possible contributing factor was a weakening Fuel Pump? I just don't know.

Still doesn't answer the Old PCM killing the engine by tapping on it...that too was replaced.

I'll stay in -touch....

 

The PCM is just a motherboard in a metal case...ANYTHING can go wrong at any time for no reason...the other factors are common breakdowns that also can happen anytime .....soo I wouldn't be so hard on yourself.........I had to change a fuel pump twice in 50 K along with 2 IDMS .... you never know....

 

I got to admit,i am having some issues along the idle lines.it steps up,then down,no ryme nor reason.maybe i should replace cps and have the old as a spare...

 

CPS should throw a code if it causes the truck to stall. So will most other things. Did you get any codes at all when you scanned it? Have you checked for a loose ground or corroded battery cables? The additional load of the AC may point to a voltage problem.

 

No codes were thrown, other than when I unplugged the ICP, and along with the code I had the CEL....Live data showed Vehicle voltage power was 13.5 +/-, which seems a little low for the alternator, but I don't know what the reg. output should be, at least it was higher than battery voltage.
Old CPS was black, decided to try one from a IH dealer, and their's is grey and made in Mexico. Ran her again tonight...fingers crossed.

 

I did save each A/E session and I'll print out the excell spreadsheet of the sensor parameters that I used and look harder at the numbers. Live data screen shot is kinda hard to compare, but the spreadsheet at least has a time hack reference.....as I stated or seemed that the IH CPS did respond quicker at start-up and seemed more stable during the cycling of the A/C load.
I'll look at the data this week...lol

 

You may need to clean the FPR screen .. That is how the system removes the air from the fuel ...

 

Hmm,thanks,i will try that.sorry,did not mean to hijack at all.