I loaned a friend my truck while his tahoe was down. He only drove it one time in the 3 weeks that he had it. It ran fine in the weeks before I took it to him an the day that he did use it. Normally pulling 19' boats.

I was supposed to swing back by his house and pick it up a few weeks ago but it will not start. I have no clue as to why it runs fine then wont hit a lick. I had the Superchips code reader and it pulled a few codes relating to exhaust back pressure so I replaced the sensor and went to blow the line out and found that it was busted. So now it has a new backpressure sensor and tube to manifold.

I also replaced the CPS since it was not that expensive. The truck is now turning over fine but wont start. There is NO SMOKE from the exhaust pipe. NONE. I did not look for this until this morning after reading post yesterday.

I did read on here a few things to note and have the following to report:

1. Wait to start light is functioning all the starts
2. Oil level is fine on the dipstick and less than 1" from the top of the HPOP.
3. Oil pressure gauge rises after a few seconds on each attempt to start.
4. Tach rises to about 100 rpm during the cranking attempts
5. I opened the drain valve on the fuel bowl and it is venting pressure and fuel. I have verified with sound and pressure that the fuel pump is running.
5. I checked all fuses this morning and even swapped to identical relays under the hood. (Blower relay and IDM) to verify that was okay.

SO, any ideas of what to pull and try next. I am a Diesel Dummy and I normally have to find pics of what parts you are referencing.

Thanks for any input,

Anthony Gunnell

 

Have you tried unplugging the ICP sensor or checked the wiring at the IPR on the HPOP? Also, check the wiring at the 42 pin connector over the driver's side valve cover for chafing and shorted wires.

 

Hows the battery voltage during cranking and the connections? Sounds like it sat a lot for the last while.

 

^^^I agree.
Confirm that you have at 10.5 volts (while cranking). Sounds like batteries are low to me.