[glennst]

Update 12/15/19 - This weekend I changed the fuel pump. All went well with no issues. It cranked right up. I notice when checking fuel pressure when turning key on /engine off the meter screamed to 52 psi. A lot faster and stronger than old pump.. The engine run pressure was a solid 43, only up 1-2 psi compared to old pump. I also notice it idled better at 600 rpm with with old pump it was around 450-500 rpm.

I drove it about 60 miles through various conditions with no issues. During my I ran my Torque Pro app and a pleasant surprise was that I never had 1 misfire in C1-7, with C8 taking a couple misfires on a few occasions for no more than 8 total...

So far this is much better. Time will tell if it solved the stalling no start situation.. If it happens again I will look into CPS gap spacing..

 

[glennst]

Update 12/20 - arrrrggggg. It Friday but my wife called me on Tuesday (was traveling) and informed me it happened again. At least I have a good FP and learned how to change it.

Next I am tackling the CPS. I need some help / info. I am not getting any DTC codes for CPS. So should I shim existing CPS before buying a new CPS?

Shimming? I can’t quite grasp this in my mind. If I shim it I am in essence moving the sensor further away from the reluctor wheel right? So how is this helping? I would think it would need to be closer?

 

[RayVoy]

As I understand it, the shiming compensates for bearing wear.
As the bearing wears the reluctor gets closer to the sensor, the shiming restores the correct spacing.
But, to my mind, you would need a lot of wear before that became an issue.

 

[glennst]

Thanks Ray. I replaced the CPS today with a brand new ACDelco... I added a 0.02”” shim I bought from Auto-zone. It cranks and runs good, but I did not do a CKP variation relearn because I do t have a scanner to initiate the test. In morning driving to local garage and ask them to do the relearn..

I hope this fixed my stall no crank issue. Update later..

 

[glennst]

UPDATE!!!

For those interested this is summary.. Symptoms were stalling, would crank over but not start. If vehicle sat from 3-10 minutes it would crank and run on for a while. This occurred 2-3 times a week.
Feedback was it was either the Fuel Pump or Crank Shaft Position sensor (CPS).

I changed fuel pump last weekend (9 days ago) and pressure quality improved (slams to 50 psi when turning on ignition), however running idle psi only went up from 42 to 43 psi which is spec. 2 days later wife had another stall.

Yesterday I changed the CPS with new ACDelco sensor. I did add the 0.030” spacer washer/shim. Engine cranked up and idled great. No codes were present. I did not have scanner tool to initiate a CKP crankshaft variation relearn.

Today I drove to local garage to have a relearn performed and on the way my EL came on and flashed on occasion. It threw a P0300 misfire code with misfires occurring on several cylinders. All codes were cleared before relearn. After the relearn was performed all codes Remained clear and I drove 15 miles home with no EL indicators or codes.

So now I am back to letting wife drive it again and see if the stall no crank occurs. Fingers crossed hoping this is resolved. I will not post another update unless problem returns..

 

[backcountry horsewoman]

Thanks the update and congrats on fixing the problem! Merry Christmas.

 

[glennst]

UPDATE - so far so good .. The new CPS sensor was the fix.. however I wanted to clarify with all what I did regarding spacer shim. While I purchased a .020 shim washer from Autozone (part SU12931) for $10, but I did not use it.

Instead I decided to try (see pic) a retaining ring I located at hardware store. It was .030 thick for $1.50 and videos on issue and specs stated air gap must be at least .030. It did not specify the maximum. Since my CPS was replaced 1 year ago and with 235K miles and 15 years old I assume I may be having some ball bearing slippage mentioned in videos. So I figured an extra 0.010 is not going to hurt and could help..

This clip would not slide over the tip as diameter was barely under, (maybe others could purchase a larger diameter if preferred), but for me I installed it by slightly forcing the clip open and it fit nicely and retained itself using the plastic ribs on sensor near the base plate..

After installation I noticed the spacer was slightly visible and where the clip opening I was concerned air or fluid could access/escape. I sealed that spot with a small amount of Permetex Red gasket sealer..

If you can find an actual .030 washer shim that would be best, but I did save $8..

 

[backcountry horsewoman]

Thanks for the update and congrats on fixing your truck!