7.3 PSD running on 4 cylinders

[CHKNFKR]

My fullsize has decided that every system is going to fail one at a time until i have rebuilt it entirely. this week its running on the left bank only. Ranger44 has been a great help in narrowing things down. Right now it looks like either the under valve cover harness or the injector driver module. the harness from the idm to the uvch is good, but i'm too lazy to rip everything out of the way to get to valve cover and test the harness inside. I did run up to O'Reilly to jack their obd2 scanner. at first the truck was running normally and printed no codes at all. by chance it happened to start running like hell while i had it hooked up. it printed all of the following codes:

P005A - "B camshaft profile control performance/stuck off bank 1"
B1C2C
B31CF
P0BC4 - "hybrid battery temperature sensor "E" circuit low"
U3110
C3300
P0005 - "fuel shutoff valve "A" control circuit/open
C1300 - "ABS pump motor circuit failure
C38FF
U3F27
U05A6
U2197 - "Invalid data for vehicle speed"

I have only been able to identify 5 codes so far and most of them seem to be side effects of the engine running on 4 cylinders. If anyone can help fill in the blanks your help is greatly appreciated.

 

[Ranger44]

I looked up in the All Data Code Index under your truck and no p-codes matched up.

I wouldn't look too much into these codes, just take them with a grain of salt.


On Identifix I pulled up the symptom and it seems out of the 20+ hits with the same symptom/issue, 80-90% were the IDM, the other 10-20% being the wiring/connectors.

The IDM being on the fender guard tends to collect water and dies, usually being intermittent as it does. You test that yet? I have tomorrow off if you feel like messing with it.

 

[CHKNFKR]

the idm makes more sense anyway. it has a common for each bank where the uvch has a common per two cylinders. the truck intermittently shuts down the whole right bank. if it were the uvch i would only lose 2 cylinders unless both harnesses intermittently fail simultaneously. unfortunately a reman idm runs about $600

 

[--weezl--]

clear codes wait for it to happen again and check again?

 

[CHKNFKR]

did that. same results

 

[Ranger44]

Rock auto, you'd have to send a core back, but even with a core charge it's less.

 

[Ranger44]

Also if the IDM notices or thinks the ground is weak for 1 injector....it will shut the whole bank down to protect the certain injector.

SO.....it could still be either the IDM or a bad ground (wiring harness) for an injector.

 

[adsm08]

codes:

P005A - "B camshaft profile control performance/stuck off bank 1"
B1C2C
B31CF
P0BC4 - "hybrid battery temperature sensor "E" circuit low"
U3110
C3300
P0005 - "fuel shutoff valve "A" control circuit/open
C1300 - "ABS pump motor circuit failure
C38FF
U3F27
U05A6
U2197 - "Invalid data for vehicle speed"

The B codes are body codes, the U codes are network codes, and the C codes are chassis. Most of them are likely unimportant to your issue.


My first thought when I read that was IDM though. I'm more of a 6.0 guy, if that was happening on a 6.0 I'd go after the FICM right off. The IDM is the 7.3's equivalent of the FICM.

 

[CHKNFKR]

my new idm showed up today, just finished the swap. the new one came with a far more extensive diagnostic test to verify that faulty wiring in the truck did not cause failure and will not cause failure again, everything checked out. now that the new one is in, I've got the block heater plugged in. after i have lunch I'll try to start her up.

 

[CHKNFKR]

I just realized i never posted a proper update. the new idm is in and working wonderfully. I really think the old one was going bad for a very long time and finally just quit. now that the new one is in the engine runs so much smoother from idle all the way to the rev limiter. i have better pedal response than i've ever had, better boost response than i've ever had. it runs significantly quieter than it ever has. it warms up faster but tops out about 10* cooler than it used to. best of all, i'm getting about 2 - 2.5 extra miles to the gallon. who would have thought a V8 runs best when its running on all 8 cylinders?

 

[adsm08]

Well, in a diesel it actually makes quite a bit of sense that you are getting better mileage and the engine is running cooler. More fuel = more heat.

 

[CHKNFKR]

i think the biggest thing is the engine isn't losing power across half its cycle then having to compensate for it on the half cycle that it's actually working. also the turbo just barely got going at 2500rpm and half that boost was dumped into dead cylinders. now she spins up around 1200 rpm and none of the boost is wasted.

I'm like a little kid with a new toy. this has really woken up my truck, its like a whole new engine in it!

 

[CHKNFKR]

It's back....

Only worse now. The truck will start and run normally for all of 4 seconds or so, cel comes on rpms start to drop then its dead. No amount of skinny pedal has any effect. Uvch tests good. Injectors test good, idm tests good. Koeo gives me same codes as above, can't keep the engine running long enough to run koer...

***edit

Completely unrelated but kinda funny, t9 on my phone let me mis spell amount up above but changed koeo and koer to coeo and coer, silly phone.

 

[adsm08]

I'm wondering if you aren't having fuel pump issues this time.

Have you checked your pressures?

 

[CHKNFKR]

Well now i can't even get it to start at all. Cranking pressure is 21.5# idk what normal is but that seems kinda low to me. I think idle pressure is supposed to be 55-60, "wot" is up to 90, never have seen what crank pressure should be.