It is my understanding, if the by pass valve is missing, the engine will not build enough oil pressure to fire the injectors. The early engines had the by pass staked in, the later ones have a snap ring to hold it in.

 

Thanks Tom. I can the injectors clattering while cranking, would this noise be indicative of enough oil pressure?

 

Meant to say hear them clattering.

 

I'm going to say that the "clattering" you hear is the selinoid on top of the injector working, oil pressure actually "fires" the injector. But don't take thais as the gospel. Someone with more knowlage will chime in on this. I don't remember, but have you checked the fuel pressure at the schrader valve on the bowl? You should get around 50 lbs. while cranking. You can check the fuel pressure with a cheap stick type tire gauge, but you will need someone to crank the engine over whil checking the FP.

 

Yep,got @ 50-60 psi with a tire gage. Going to put a 1000psi gage on the oil line at the HPOP right side today to see the real pressure reading. Is it possible to not see the parts from the bypass on top of the filter when removing it? I mean, would it have just fallen into the return port at some point in time? The truck was running ok before I changed the oil.

 

I've never had one fall out, thank goodness. But from what I understand, it would be on top of the filter, or it would fall into the drain pan when the filter is removed. In the pic that Rick posted in post #25, the by pass valve is in the 4 oclock position. If you remove your oil filter, you can see pretty easily if the valve is gone.

 

Ok, will do.

 

And thanks again

 

First, thanks to all who have replied, lots of input is appreciated.
I still have a no start tho, so here's what we tried since last post. Checked HPOP pressure on right bank,over 1000 psi on the gage.disnt try drivers side thinking if one side works, both should have same pressure. Tried fuel can to pump, thinking maybe i had a restriction from on-board tank,no change,no start. Unhooked wiring harness to engine,checked wires for continuity,found no shorts.
Changed the IDM with one out of a running 2000 super duty, no change. Anybody know how to check the injector wiring for voltage? I mean which pin to check at the harness? I am at the point of thinking its the PCM because I can't find voltage anywhere on the harness at the valve cover/ harness junction, but am unsure I'm checking the right pins.

 

Just to make sure, are you getting a wait to start light when you first turn the key? If not check fuse 22 in the under hood power distrubition box. If it is blowenn unplug the fuel bowl heater, and replace the fuse, as it powers the fuel heater and PCM relay. You probably know this, but sometimes we overlook the easy things.

 

After trying a new icp and ipr, it still won't start. Borrowed an auto enginuity scan tool from a buddy in Reno, hooked it up and ran a scan code test. Got a P1280 code, (low icp input). Did a buzz test, all 8 injectors passed, no issues. The KOEO test numbers are, (icp,2730), (ipr, 14.21), (FPW,.22), (Volts,12.65). HPOP oil level is full,new cps,all wiring checks out good, (I took the loom cover off and checked every wire on engine harness after unhooking it at the connector). It tries to start after a short crank,5 seconds or less, just kinda, so I am wondering..... It just seems like it wants to run, but falls off, like the HPOP pressure drops maybe. I don't understand the .22 fuel pulse width number. Can anyone help me with some details on these numbers maybe?

 

When trying to diagnose hard start or no start issues a scan tool is needed to check and monitor the ICP (Injection Control Pressure), RPM (From the CMP) Vehicle Voltage during cranking and PW (Pulse Width) signal.

1. RPM, minimum 100 rpm cranking speed (When warm it should be over 180 rpm)

2. ICP, minimum required for starting 500 psi if no rpm signal, ICP won't go over 400 psi

3. Voltage during cranking 7-10 volts minimum depending on year

4. Pulse Width; 0 ms means no sync, 1994-1997 .42 ms indicates that PCM and IDM are in sync (on 99-03 it should be .60 ms) and the PCM is waiting on the ICP to reach the minimum pressure. When min. ICP is reached PW should change to 1-6 ms

Is the truck cranking fast?

 

It's cranking between 160-180 rpm.Put a AE on it to get those numbers.

 

You said volt between 7 and 10. Is that battery voltage? Also, it's cranking between 160 and 180 rpm.

 

The pulse width is reading.22 according to the AE scan tool.