P0088 code, truck did not turn off upon keying off ignition.

[Josh Martinez]

Hey everyone,
Had a CEL come on, turned my truck one and I was receiving the codes. Got my codes and went to key off my truck, the truck stayed running. Before it died out on its own the dash lights came on and my oil pressure dropped all the way down.
I attached 2 photos of what my scanner is telling me. While it was on I was able to rev it just fine, felt like it still has power.
Ive replaces the FCA before, the injectors were done at a reputable shop less that 30k miles ago, SS 60% overs with a hard way efi live tune.
The code did pop when I was getting on it going fast down the road
It’s my daily so any help is appreciated! Thank you and have a great day!

 

[Ozymandias]

Only thing i can think of is electric part of your ign. Switch.

Because, its the ECM that commands the engine to run, and it only does it as long as the mentioned switch tells him to do so.
You can entirely forget about all the hard parts that you changed already, they have nothing to do with this behavior.

And the ign. Switches are prone to fail after some years.

 

[Josh Martinez]

Would that switch throw a high pressure code though? my buddy was telling me it could be an injector stuck open.

I’m hoping it’s a sensor only. Since that would be the easiest fix probably the cheapest too.

 

[Ozymandias]

No it cant, and those generic code readers are well known for inaccuracies.

If the ECM says off then its off.

And a stuck injector, you would see and hear, believe me that.

 

[Ozymandias]

The e-part off the ign. Switch is actually pretty cheap though.

 

[Josh Martinez]

The e-part off the ign. Switch is actually pretty cheap though.

Interesting, I have some other folks telling me it could be leaking oil past the crush washers of my injectors and stuff, how would rule that out?

 

[Ozymandias]

Oh well, there is a difference in how an engine runs, smooth and as desired or on secondary fuel.
Like said, you'd hear and see if it does it that way.

Has it had a clean idle during that key off run or rough and bumpy.
How did it go out, slowly falling rpm till it quit or like normal within half a second finish?


On your engine is no oil behind the crush washer, there's diesel.

 

[Josh Martinez]

Oh well, there is a difference in how an engine runs, smooth and as desired or on secondary fuel.
Like said, you'd hear and see if it does it that way.

Has it had a clean idle during that key off run or rough and bumpy.
How did it go out, slowly falling rpm till it quit or like normal within half a second finish?


On your engine is no oil behind the crush washer, there's diesel.

It slowly died, there was no increase in rpms just slowly went out. Maybe 5 to ten seconds after I keyed off it died

 

[Ozymandias]

Okay, noted.
Can you reproduce it or was it a single event?

 

[Josh Martinez]

Okay, noted.
Can you reproduce it or was it a single event?

I haven’t tried to reproduce, I suppose I could go turn it on see if it happens again. Just don’t want it to run away lol

 

[Ozymandias]

If you fear that, and yes it could happen, then prior take off the air filter assembly and keep a sheet metal handy to plug the air intake. Thats the only way to stop a runaway condition on a diesel engine.

You might find this helpful to chase the P0088
https://mopar1973man.com/cummins/ar...0088-fuel-rail-pressure-too-high-bank-1-r639/

 

[Josh Martinez]

If you fear that, and yes it could happen, then prior take off the air filter assembly and keep a sheet metal handy to plug the air intake. Thats the only way to stop a runaway condition on a diesel engine.

You might find this helpful to chase the P0088
https://mopar1973man.com/cummins/ar...0088-fuel-rail-pressure-too-high-bank-1-r639/

Thank you, I’ll repost here when I figure out the issue. Unfortunately it’s my daily so I need someone who knows what they’re doing to figure it out. I’ll be taking this thing in.

 

[Ozymandias]

By the way, any mods on the truck? Tuner, anything else?

 

[Ozymandias]

Thank you, I’ll repost here when I figure out the issue. Unfortunately it’s my daily so I need someone who knows what they’re doing to figure it out. I’ll be taking this thing in.

Go to a reputable Diesel shop with it, often they are better then a Dodge Dealer ship.

 

[cerberusiam]

Interesting, I have some other folks telling me it could be leaking oil past the crush washers of my injectors and stuff, how would rule that out?

If you have oil leaking past the crush washer s you will have massive amounts of crankcase blowby, easy to check. The crush washer seals compression in also.

A more likely place for oil is form the turbo, check your intake tract to make sure it isn't being oile ddown by the turbo shaft seal.

Pull the TQ tube and keep a board handy that will cover the turbo inlet, if it runs away and won't shut off shut the air off with a board. It will die then.

 

[Josh Martinez]

Go to a reputable Diesel shop with it, often they are better then a Dodge Dealer ship.

If you have oil leaking past the crush washer s you will have massive amounts of crankcase blowby, easy to check. The crush washer seals compression in also.

A more likely place for oil is form the turbo, check your intake tract to make sure it isn't being oile ddown by the turbo shaft seal.

Pull the TQ tube and keep a board handy that will cover the turbo inlet, if it runs away and won't shut off shut the air off with a board. It will die then.

So, I found a fuze the was fried that goes to the lift pump, replaced that, cleared the code and have had it occur since. I’ve been looking at my tail pressure via the live data stream on my scanner to see if it’ll get close to 26k the highest I’ve seen it reach it 18ish. So hopefully it doesn’t occur again. Although I will still check for oil gathering hopefully it’s not a leaky turbo seal... not sure how difficult those can be..

 

[cerberusiam]

Unless you have a tuner you never see RP at 26k psi aside form shutdown spikes, about 21k psi on +04.5 or 18-19k psi on pre 04.5, is the max on normal tuning under a load.

Low LP pressure should not cause the symptoms you describe unless there is a sticky injector.

 

[Josh Martinez]

Unless you have a tuner you never see RP at 26k psi aside form shutdown spikes, about 21k psi on +04.5 or 18-19k psi on pre 04.5, is the max on normal tuning under a load.

Low LP pressure should not cause the symptoms you describe unless there is a sticky injector.

Yeah I do have a tuner, efi live from hardway, and I was on it when it threw the code. That’s why it makes me think it was the ignition. The truck didn’t increase rpms or anything when it didn’t turn off. But I see what you mean. So if I were to take the pipe off that goes into the air horn and into the inter cooler? If there’s oil in the bottom side that is indicative of turbo seal leak? I’m afraid that I blew it giving it all it’s got lol

 

[cerberusiam]

Check from the turbo to the CAC, that would be where the bulk of the oil is if the turbo went.