No start condition: Help me figure out what's left...

dgeist · **Posted:** Sat Feb 09, 2019 2:37 pm

A couple weeks back, I had the "restricted gearing and RPMs" mode kick in during some aggressive driving. I figured an overboost or something else transient, so I pulled over, let things cool off for a moment, then it started right back up and was fine. This happened a few more times over the next couple days, so I figured it was a fuel restriction of some kind. As long as I drove slowly, it was fine. I figured a new filter would help since it was overdue anyway. Well, it hasn't started since. Here's what's been done:
- Replaced fuel filter
- aftermarket head stanadyne key-lock system
- replaced with Napa/Wix fitment with same specs 2 micron
- lift pump primed it just fine and I've tested the output side and found plenty of flow into a clean jar.
- Replace Crankshaft Position Sensor
- After figuring out you really need to be above AND below to do this, it wasn't bad.
- No start
- Checked battery since some electronics had been acting wonky anyway
- New 800 CCA battery installed
- No start
- Checked rail pressure and found there was never more than 190 psi
- It starts around 90 ambient and will jump to 150 or 190 during cranking, but that's all
- Checked fuel pressure sensor
- after unplugging, it correctly jumped to 26k or some such.
- Ran with fuel pressure solenoid unplugged
- No change in pressure
- Swapped out fuel rail entirely
- two different complete rail/sensor/solenoid set
- Thank you Geordi for the loaner
- No change
- Unplugged return lines from all four injectors
- wiped dry and watched for leaks during cranking.
- no leaks, no change.
- Unplugged fuel volume solenoid from the back of CP3
- what harm could it do
- no change

At this point, I've been without a daily driver for over 2 weeks and am running out of things to test and try. Does anyone have any suggestions on things I can test? I know there's a bazillion electrical things that can cause hard operation, but at this point, I'm just worried about getting fuel pressure to open the injectors and having combustion.

Dan

rankom · **Posted:** Sat Feb 09, 2019 5:06 pm

any codes?? i read one tread that guy had similar problem and he found that some guy suggested capping injectors at rail one at time and he found open injector #3 so he was able to run it on 3 cylinders just for testing ,but this should set a fault code , lot of people , dont bother testing, they replace parts from map sensor to cp3pump, dont follow them please

dgeist · **Posted:** Sat Feb 09, 2019 5:43 pm

rankom wrote:

any codes?? i read one tread that guy had similar problem and he found that some guy suggested capping injectors at rail one at time and he found open injector #3 so he was able to run it on 3 cylinders just for testing ,but this should set a fault code , lot of people , dont bother testing, they replace parts from map sensor to cp3pump, dont follow them please

Yep, been keeping up with the codes. The only persistent codes are from 2 bad glow plugs on the "to do" list. Obviously as I've unplugged things to test behavior, most of them has resulted in a corresponding "low sensor" failure, etc. Nothing related to the actual original condition, though (the limp home). Right now, that's a P1265, P1267, and P2294 (since I'm running without the fuel pressure regulator to try to build pressure in the rail).

I'm wondering if it's possible fuel starvation could have damaged the CP3.... or if a bad MPROP would cause a low fuel flow condition on crank. But I am at a complete loss on how to validate without tearing the whole front end apart.

Dan

flash7210 · **Posted:** Sat Feb 09, 2019 6:31 pm

P2294 is for the fuel rail pressure solenoid.
If that’s unplugged the rail will not build any pressure.

Now, the fuel quantity solenoid on the CP3 can be unplugged and that will send most of the fuel up to the rail. Unplugging it should set a p0090 code

Do you have a way of reading the fuel rail pressure sensor?
That would be helpful.

dgeist · **Posted:** Sat Feb 09, 2019 6:50 pm

flash7210 wrote:

P2294 is for the fuel rail pressure solenoid.
If that’s unplugged the rail will not build any pressure.

Interesting...I thought it was the inverse: a normally closed solenoid where it would not REDUCE the pressure unless it was plugged in. Are you saying it's normally open?

flash7210 wrote:

Now, the fuel quantity solenoid on the CP3 can be unplugged and that will send most of the fuel up to the rail. Unplugging it should set a p0090 code

Yep. Got that one. Unfortunately, I've read it doesn't do anything until 30 seconds after startup (i.e. it's not used during crank..)

flash7210 wrote:

Do you have a way of reading the fuel rail pressure sensor?
That would be helpful.

I do. Ambient with key-on is about 90psi. When I crank it (and I'm talking multiple times adding up to minutes), it'll climb to the 120s/150s/190s, but I've not seen it over 200psi. Obviously, that's no enough to open the injectors. That's why I tested the injectors. None of them spilled a drop during cranking with the returns wide open...again, reinforcing the REALLY LOW RAIL psi thinking.

Dan

flash7210 · **Posted:** Sat Feb 09, 2019 7:30 pm

Yes, the fuel rail pressure solenoid is normally open.
If you were to unplug it with the engine running it would immediately die.

The fuel quantity solenoid is also normally open.
But it’s open position diverts all fuel up to the rail.

Remove the return hose from the rail.
Plug the hose end.
Watch the return outlet while while cranking.
No fuel should come out.

Mountainman · **Posted:** Sat Feb 09, 2019 7:52 pm

I've fixed 2 CRD'S that were like yours, and they both had a toasty pin at the ecu for the rail solenoid. + of the two pins were just noticeably darkened from micro arcing. I scrubbed them clean with a tiny piece of sandpaper or screwdriver, bent them a TINY amount so they would still feed in the female side just fine, but they made better contact. Oh, and dielectric grease made it a permanent fix.
How many miles on that CP3? I have yet to see one fail, even after lots of air in fuel and 200k miles on one CRD.

dgeist · **Posted:** Sat Feb 09, 2019 9:32 pm

I'll try with the borrowed rail solenoid plugged in. Fingers crossed

Oh, and the engine has about 140mi on the clock.

Dan

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vwroad87 · **Posted:** Sun Feb 10, 2019 12:25 am

dgeist wrote:

I'll try with the borrowed rail solenoid plugged in. Fingers crossed

Oh, and the engine has about 140mi on the clock.

Dan

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Please report your findings, hoping this is a fix. I've got a buddy that has similar stuff going on in his CRD.

dgeist · **Posted:** Sun Feb 10, 2019 9:35 am

I plugged the rail solenoid back in (and that code went away). Still had crank but no fire. I unplugged the rail drain hose at the bottom end to see if I was getting any leakage, and it was, but not from the hose, but from the plastic cluster.

So, I removed the injector drain tips to see if one of them was leaking (even though I didn't think they were before). They didn't, but I still got some leakage out of the plastic cluster. Does that mean I'm just seeing some overflow from the high pressure pump's return circuit?

Should I maybe pop the input off the rail and catch whatever comes out while cranking and measure it? Seems like an inexact way to measure anything (i.e. not under much of any load).

Dan

rankom · **Posted:** Sun Feb 10, 2019 10:15 am

this tool my work on our CRD , miller 9011 , works on duramax , and cummins5.9

flash7210 · **Posted:** Sun Feb 10, 2019 11:16 am

dgeist wrote:

I plugged the rail solenoid back in (and that code went away). Still had crank but no fire. I unplugged the rail drain hose at the bottom end to see if I was getting any leakage, and it was, but not from the hose, but from the plastic cluster.

So, I removed the injector drain tips to see if one of them was leaking (even though I didn't think they were before). They didn't, but I still got some leakage out of the plastic cluster. Does that mean I'm just seeing some overflow from the high pressure pump's return circuit?

Should I maybe pop the input off the rail and catch whatever comes out while cranking and measure it? Seems like an inexact way to measure anything (i.e. not under much of any load).

Dan

The CP3 is always returning some fuel back to the tank.
I try not to mess with the plastic junction block. It’s very easy to break.

Next, hook everything back up and normalize everything.
Crack open any one of the metal injector lines.
Crank the engine and see if fuel comes out.

Mountainman · **Posted:** Sun Feb 10, 2019 1:06 pm

dgeist wrote:

I plugged the rail solenoid back in (and that code went away). Still had crank but no fire. I unplugged the rail drain hose at the bottom end to see if I was getting any leakage, and it was, but not from the hose, but from the plastic cluster.

So, I removed the injector drain tips to see if one of them was leaking (even though I didn't think they were before). They didn't, but I still got some leakage out of the plastic cluster. Does that mean I'm just seeing some overflow from the high pressure pump's return circuit?

Should I maybe pop the input off the rail and catch whatever comes out while cranking and measure it? Seems like an inexact way to measure anything (i.e. not under much of any load).

Dan

You're crazy if you haven't checked the commonly cooked pins at the ecu. Takes a bright light, a good set of eyes, and about 1 minute...

dgeist · **Posted:** Sun Feb 10, 2019 2:22 pm

Mountainman wrote:

You're crazy if you haven't checked the commonly cooked pins at the ecu. Takes a bright light, a good set of eyes, and about 1 minute...

No names please

It's on my list, just have very limited time chunks to work on things and very few of the chunks, so having to pick and choose.

Do you happen to remember which pins we're talking about?

Dan

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Mountainman · **Posted:** Sun Feb 10, 2019 2:44 pm

dgeist wrote:

Mountainman wrote:

You're crazy if you haven't checked the commonly cooked pins at the ecu. Takes a bright light, a good set of eyes, and about 1 minute...

No names please

It's on my list, just have very limited time chunks to work on things and very few of the chunks, so having to pick and choose.

Do you happen to remember which pins we're talking about?

Dan

Sent from my Pixel 2 using Tapatalk

Sorry Dan, I woke up on the wrong side of the bed this morning :evil:

Um, I want to say 30 or 31. But, with good vision, you might be able to see it without pulling the ECU out, so I probably should have said 10 minutes. The pin in question will just be dark compared to all of the rest, so hopefully you won't even need the pin number. Get someone with good eyes to inspect it if you don't have 20/20, as it's easy to overlook.

dgeist · **Posted:** Sun Feb 10, 2019 6:13 pm

Mountainman wrote:

Um, I want to say 30 or 31. But, with good vision, you might be able to see it without pulling the ECU out, so I probably should have said 10 minutes. The pin in question will just be dark compared to all of the rest, so hopefully you won't even need the pin number. Get someone with good eyes to inspect it if you don't have 20/20, as it's easy to overlook.

Okay, so no fried pins on the ECU. They all look pretty clean and already had a coat of dielectric on there from when I got my GDE tune in 2009.

I opened up the 18mm supply port on the rail and put it in a rag. Cranked and soaked the rag pretty quickly. Then I disconnected the pump flow solenoid/FCA/ M-PROP (to allow unregulated "full flow") and disconnected both the return line on the rail AND the return port on the #1 injector (just left it hanging there). The only place fuel came out is plastic return cluster.

I guess in hindsight, that really only proved that #1 injector wasn't leaking. The flow out the cluster could have been from either the return circuit on the pump or injectors 2-4, right?

(brain hurting...I want to fix this so I can stop thinking about it).

Dan

flash7210 · **Posted:** Sun Feb 10, 2019 6:25 pm

All the injector return lines are tee’d together. So if any were leaking out the return, you would have seen it come out of the #1 return you disconnected.

I think you’ve determined that fuel getting up to the rail, co the CP3 is good.
The fuel rail pressure solenoid seems to be functioning properly.

You either have a suck open injector or a bad cam sensor or a bad crank sensor.

dgeist · **Posted:** Sun Feb 10, 2019 6:42 pm

flash7210 wrote:

The CP3 is always returning some fuel back to the tank.
I try not to mess with the plastic junction block. It’s very easy to break.

Next, hook everything back up and normalize everything.
Crack open any one of the metal injector lines.
Crank the engine and see if fuel comes out.

I opened the feed from the pump right in the front of the rail. It gushed. I opened hard line #1 coming out of the rail. It also gushed.

Still no fire. Still no visible leaking from the tops of the injectors (just left the return plugs off while cranking).

flash7210 · **Posted:** Sun Feb 10, 2019 7:02 pm

Also.
Check the ASD fuse and ASD relay.

And make sure that the red dot in the instrument cluster is not lit.

dgeist · **Posted:** Sun Feb 10, 2019 7:23 pm

flash7210 wrote:

All the injector return lines are tee’d together. So if any were leaking out the return, you would have seen it come out of the #1 return you disconnected.
I think you’ve determined that fuel getting up to the rail, co the CP3 is good.
The fuel rail pressure solenoid seems to be functioning properly.
You either have a suck open injector or a bad cam sensor or a bad crank sensor.

Hmm, so I haven't seen any smoke (white/grey/otherwise), so unless I'm missing something, there's no injector leak (either direction). Replacing the Crank Position Sensor is actually the first thing I did with no-start, so I doubt that's it. On the cam position sensor, I've not replaced that, but would it even matter if I'm not getting enough pressure on the rail?

I checked both the ASD fuse and relay. The light is lit when I leave the key in "on" position, but goes out after cranking (like most of the other lights).

Dan

No start condition: Help me figure out what's left...

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