Engine Codes

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Briann1177

Goblin Guru
I'm in the process of trying to overcome a P0101 (MAF) in my donor before I start disassembling it. I'm probably wasting my time with it, but it kind of got me thinking. Based on info I found, it appears the the ECM is fairly sensitive to air flow and even a change such as putting on a cold air intake can set it. Also with that code active it will disable the boost controller.

To the boosted owners, did you have any issues with this?
 
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taz_va

Member
Did you verify the wiring to the MAF is good, and that the MAF is undamaged? What have you done to overcome it?
 
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taz_va

Member
Nuker brings up something else, was there a custom tune? It's possible they tuned out the MAF but left the code in (which would be odd, but I've seen it before).
 
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Briann1177

Goblin Guru
The air filter was replaced, MAF cleaned, and crankcase vent hooked back up. The vent was completely broken off when I bought it. The vehicle was involved in a front end collision so there might be some damage to the charge air cooler or plumbing somewhere causing an air leak.

Nuker, mine runes "fine" with that code, but there are two things I noticed immediately driving it home. It was dog slow and the boost gauge only went up to 2-3 PSI under a very heavy foot. Come to find out, a P0101 code is one of those codes that will put the computer into a "limp" mode by disabling the boost.
 
TheNuker

TheNuker

Goblin Guru
Ah must be different with the turbo vs SC cars. Mine was making about 10 psi running with no issues without MAF.

Nuker-
 
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Briann1177

Goblin Guru
Besides Lonny/Adam, does anybody else have a turbo Goblin? I'm not too worried about this code for now. I'm more thinking to the end of the build, having this code, and not being able to get rid of it.
 
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taz_va

Member
I wouldn't be concerned with it at the moment. If the ECM can't read airflow properly, it'll use alternate lookup tables to keep the motor going. I usually simply went Speed Density and ditched the MAF altogether when I was building larger motors, because the MAF couldn't read the airflow beyond a certain point anyhow.

I've seen cases where people used brake cleaner on a MAF and it messed it up, necessitating replacement, I've also seen where a bad ground, or a hole in the intake tube (between the MAF and intake) caused these sorts of codes.. no major concern.
 
Adam

Adam

Administrator
Staff member
Briann1177 said:
I'm in the process of trying to overcome a P0101 (MAF) in my donor before I start disassembling it.
Click to expand...
It is definitely a good idea to fix this before disassembling the donor.

We found a broken wire going to the MAF sensor on our turbo car. It was broken right next to the MAF connector. Here's the schematic for the MAF wiring:
Engine Controls Schematics (engine Data Sensors - Pressure, Temperature) LNF

Engine Controls Schematics (engine Data Sensors - Pressure, Temperature) LNF


The black/white wire should go to ground. The pink/black wire should show 12 volts (only when the key is on I think). The other three wires will go to the X161 connector in the engine compartment. Here's what that connector looks like:
X161 Body Harness To The Engine Harness LNF

X161 Body Harness To The Engine Harness LNF


X161 Body Harness To The Engine Harness LNF Table

X161 Body Harness To The Engine Harness LNF Table

 
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Briann1177

Goblin Guru
I just spoke with the Chevy Stealership, and they said the intercooler has a crack in it that is big enough to disrupt the air flow and throw the code. It was totaled out in a front end collision so I'm not surprised. He also said a new one is pretty pricey. At this point I don't think I'm going to worry about it as all the turbo plumbing will be taken out and replaced.

Adam, did you guys have any air flow issues when you completed the turbo'd Goblin?
 
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Briann1177

Goblin Guru
Welp, the dreaded P0101 code is back in the Goblin. I believe the dealership replaced the MAF when I took it in last year before tear down because it looks brand new. It's a very frustrating code for the turbo owners because it will disable the boost. It's still fun without the turbo, but it's really on another level when it kicks in to 20 PSI.

The PCV is hooked up, the vacuum line is hooked up, MAF is pointing in the right direction, and all connections appear to be solid. I'm really at a loss on this, and a little frustrated right now.

Any thoughts?
 
ctuinstra

ctuinstra

Goblin Guru
Just a thought here. Read this highlighted passage. Are you 100% sure you have the correct connections on the MAP and the BARO sensor? They are the same plug and can be swapped. At least this is the case on our SS/SC. I had to look up the wire color to make sure I was plugging the correct one in to each sensor. The only other thing would be a air leak in the intake track.

I don't suppose this car ever had a tune on it? The freq of the MAF can be changed and maybe it's not correct..

I assume you have checked many of the other items.


1534294112703.png
 
ctuinstra

ctuinstra

Goblin Guru
Briann1177 said:
I don't know what the BARO sensor is. Is that the same as the MAP sensor on the intake manifold?
Click to expand...
They are actually the exact same sensor, just placed in two different spots. The Manifold Absolute Pressure (MAP) is in the intake manifold, the barometric (BARO) sensor is mounted outside of the engine and exposed to the atmosphere. Mine is mounted on a metal tab up by the valve cover by the fuel line connector.
 
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Briann1177

Goblin Guru
Can somebody confirm the direction that the PCV check valve needs to flow. Does the flow need to be from valve cover, through check valve, and to intake (flow arrow pointing towards intake)? Or does it flow from intake, through check valve, and to valve cover (flow arrow pointing towards valve cover)?
 
SliderR1

SliderR1

Well-Known Member
Not for sure on the LNF, but the way I understand the LSJ, the flow goes both directions depending on whether you are under boost. I don't think the LSJs have an external check valve like you describe. If it can only go one way, I would assume that should be from valve cover to intake.
 
SliderR1

SliderR1

Well-Known Member
Yeah, I think you are right. From what little research I just did, the LNF PCV system is TOTALLY different from the LSJ.
 
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