Starts then dies...

[red4x4neck]

Originally Posted by tcgrmt

That starting RPM seems really low. Is that with the batteries charged up?

The ICP needs to see 500 PSI to start.

What sensor are you using to get fuel pressure? I don't think our trucks have a true fuel pressure sensor that provides data to the PCM.

I just got some more info from Dale Isley (Tymar Performance) and you are right our trucks PCM's do not pull fuel pressure. Seems curious but they don't.

As far as the engine rpm, I can tell you that the motor is turning over faster now than when the problem started, and I have replaced the CPS (Which didn't fix the original problem) Maybe I need to throw my original CPS back in and see if it will fire and what RPM value it outputs.

Rob

[tcgrmt]

I tried cleaning my IPR and changing the "O" rings but it wouldn't start at all afterwards. End up putting a new IPR in and it fired right up. The truck is still acting up but at least it's running. There is a test for the IPR coil in the trouble shooting section of the service CD. You measure the coil with an OHM meter but I don't remember what the value was and the CD is at work.

Maybe someone else with the CD can look it up.

[mikey0460]

I would say its your injectors. I had the same problem with my 6.0 about a month ago. Mine would start and soon die shortly after.Sometimes it wouldn't start, but once it started and got warm it ran fine for about 15 minutes i blew the 1st 3rd and 5th injector in my truck i'm bettin money thats where your problem is.Good luck with the truck.

[red4x4neck]

Originally Posted by mikey0460

I would say its your injectors. I had the same problem with my 6.0 about a month ago. Mine would start and soon die shortly after.Sometimes it wouldn't start, but once it started and got warm it ran fine for about 15 minutes i blew the 1st 3rd and 5th injector in my truck i'm bettin money thats where your problem is.Good luck with the truck.

I appreciate the advice.
I pulled the valve covers this evening and had a friend crank it over and do some data collection while I inspected the injectors for leakage/oil passage.
I observed absolutely no oil from any injectors either out of the oil spouts or the seals admittedly though it is very difficult to tell whether I was seeing the entire seal area.

If you look in my photo gallery at left I took a screen shot of the values that my autoenginuity software produced for the different aspects of ICP versus engine RPM. You will see to photos in my gallery one of them is just a bigger resolution they hold the same values.

As you can see my ICP doesn't rise above 160 with the ICP sensor connected. With the ICP sensor disconnected the pressure value went right to 2400 psi but nothing came out of the injectors and the engine didn't even try to start.

I don't observe any cross contamination between oil and fuel which I would suspect if the oring between those sections on one or more injectors was gone. That leads me to think that i may have an IPR that is not functioning as advertised.

I wish I could find some of the adapters and plugs that my Tech manual CD talk about for testing the output of the HPO system.

Any thoughts?

Rob

[tcgrmt]

Check the resistance of the IPR coil, should be 5 to 20 ohm's.

[red4x4neck]

Originally Posted by tcgrmt

Check the resistance of the IPR coil, should be 5 to 20 ohm's.

Thanks
unfortunately mine ohms at 9.3 ohms so I am not sure if mine is toast or not.
With only 150 psi at startup rpm it makes me wonder if I have a failed injector oring but it would seem awefully large amount of pressure to be leaked by one injector. So if it is my injectors leaking by then it would have to be several that failed with in a short period of time. Seems a little odd that I would have that happen.

What really ticks me off is I am such a tight wad that I cant bring myself to throw in the towel and rering the injectors, buy an IPR and an ICP sensor and be done with it.....

Rob

[action4478]

Red 4 x4 ..With the ICP connected & a good gharge on the batteries ,,read ICP Pressure & IPR DC% while cranking

This is from another member that has AE (Pocket)

When my truck wouldn't start, I watched ICP pressure, voltage, and duty cycle along with the engine RPM's. I cranked for about 10 seconds or so, and watched as the ICP voltage and duty cycle increased, but the pressure did not. It stayed between 100-130 psi no matter what. That told me that as voltage and duty cycle increased, the IPR was not responding and maintaining pressure. If it was a voltage issue, then it would have been the ICP sensor itself.

If I remember correctly, to start you need at least 400 psi of high oil pressure, and 0.8 volts on the ICP.

[red4x4neck]

Originally Posted by action4478

Red 4 x4 ..With the ICP connected & a good gharge on the batteries ,,read ICP Pressure & IPR DC% while cranking

This is from another member that has AE (Pocket)

My IPR votage with a duty cycle of 50% is only .38 volts does that sound right?

thanks

Rob

[mikey0460]

you got me stumped like i said i had that problem with my 6.0 and i shot 3 injectors.If i were you i'd swing by the dealership to pick one of the mechanics brains to see what they think.As far as adapters go i would look online maybe e-bay.I wish you luck let me know how things work out for you good luck.

[action4478]

Originally Posted by red4x4neck

My IPR votage with a duty cycle of 50% is only .38 volts does that sound right?

thanks

Rob

It sounds like the the IPR is stuck open

50 % duty cycle is roughly all you get whrn fully closed

That is what the PCM is calling fpr because the ICP is not reporting enough pressure ..

Unless you want to hook up a guage to test the heads & the pump pressures separately ..

you might just have to replace the IPR as a test ..

If you want to try pressure testing with a guage ,,,

some instructions here ...

[QUOTE
Here is what is needed to put a gauge together thanks to Swamps site.

If you don't have access to a scantool, then go to your local hydraulic supply
house, and have them make you up a mechanical gauge. You might spend $60
or so on high pressure hose, fittings, and a quality 0-3500psi liquid filled
gauge....but having this hose available for future diagnostics might be more
valuable than you think.
The hose which you will need will need to be about 40" long, rated for
(minimum) 3000psi working pressure (12k psi burst rating!) with the gauge on
one end, and a #6 female JIC swivel fitting crimped onto the other.
You will also need an individual fitting to screw into the head to go from the
head to the hose.
This single fitting will be a 90degree fitting # 5 "male boss" (sometimes called #
5 o-ring) on one end of the 90, and a # 6 male JIC on the other end of the 90.
Our local hydraulic shop would label such a fitting as 5MB-6MJ90
"JIC" is nothing special...it's just 'hydraulic talk' for a 37degree flare
fitting...standard hydraulic stuff here...nothing rare by any stretch.
Looking at the top of (either) cylinder head, you'll see the factory stainless
braided oil lines (one to each head) then you'll see a few bronze colored
plugs... (Engine off, of course) Using a 5/8" wrench, remove any one of the
bronze plugs, and install the 90deg fitting into the hole. (save the plug for
reinstallation , after testing). and the O-rings are reusable, unless brittle,
cracked, etc...
The single 90deg fitting will have a "jamb nut" on the O-ring side...screw the
fitting into the head, "aiming" the 90 away from the turbo, intercooler pipes,
etc...and then tighten the jamb nut, to "squish" the O-ring also locking the 90
from "spinning" around as you attach the swivel end of the hose to the 90. No
sealants, loctite, or teflon tape are needed on "JIC" or O-ring fittings...and
don't overtighten them...usually about 180degrees with a wrench past finger tight.
] [/QUOTE]

[action4478]

More info ...here....

If you use a guage ,,unhook one of the lines from the pump & attach the guage to the line note pressure ,,,

Then ..re attach the line to the head & do the same thing with the other head , note pressure

If need be , un hook lines to both heads ,attach the guage to one ,& cap the other ,,note pressure ,,this will dead head the pump itself & tell you if the IPR is stuck open (no pressure)

The other tests are mainly for injector o rings ,,may just need to verify IPR ,,if presure there , then move on to the heads ...