Engine Running Rich, P0102 P0108 P0113, and Misfires
 

Hello All,

I uninstalled some Crawford intake blocks, had no issues with the blocks for about a year until uninstalling them.

During the uninstall, the positive terminal was disconnect from the battery but the metal part from the battery itself was uncovered. I touched the positive side with my forearm while unscrewing a passenger side intake manifold bolt. It made a large shock from my wrench and stung like a bitch

After everything was reinstalled with the intake manifold, the car can no longer idle and seems the be way off with afr. I assume its running rich from the gas smell in the air

I've checked for vacuum leaks and unplugged the maf sensor. While unplugged the car idles at a higher rpm but still does not drive properly, obviously :)

I believed it may have been a grounding issue, so I made a little grounding kit to check the ecu with speaker wire. No success yet

Here are the error codes,

P0102 - Powertrain, Mass or Volume Air Flow Circuit Low Input
P0108 - Powertrain, Manifold Absolute Pressure/Barometric Pressure Circuit High Input
P0113 - Powertrain, Intake Air Temperature Circuit High Input
P0300 - Powertrain, Random/Multiple Cylinder Misfire Detected

I've underlined the high vs low parts as I think thats the hint to where my issue lies

Any input or ideas are greatly appreciated

Are you sure you reinstalled the intake manifold gaskets .... ??

humfrz - really has no clue ..... :(

Intake manifold uses gaskets??

Doubt its a seal problem as the engine misfires just fine, seems like afr

If you have checked aĺl hoses especialy under intake manifothen those codes are pponting to a maf sensor problem make sure its plugged in corectly the intake air temp sensor is part of maf sensor and also check map sensor is pluged in as well

My money is on blown fuses

You might want to check for blown fuses as well

Find out what your AFR and LTFT/STFT are. Don't guess. You can use a cheap-o OBD2 scan tool and the inexpensive Torque app.


PSA- disconnect the negative, always the negative

I always thought the best way is to disconnect the positive first, and then the negative. And then when you are done working, hook the negative back up first, and then the positive.

Is this correct?

Nope. Always negative first.

Oh ok, I had it reversed. Thanks!

If you disconnect the positive first and accidently short it out there is still a path to ground if the negative is hooked up. By taking off the ground first you have removed that path.


Oh, and never accidently drop your ratchet across the posts. It is spectacular but messy.

Great love learning the hard way

Anyways afr is reading 13.1:1 to 11:1 between jumping from open to closed loop, seems normal

Maf is reading .9/gs with car off then at start jumps to 15, map is opposite 14.5 psi when car is off, then scales down as it stalls

Anyone know how to go sensor by sensor to check for shorts?

your probably best getting torque app as other guys said then you can monitor maf and map sensor inputs to ecu as well as intake air temps if you see no movement on those wensors you have a problem. If all three dead suspe t a fuse google brz wiring diagram ft86 club will get you wiring diagram you may also need the repair manual google that as well

When googling, worth specifying in site:ft86club.com like syntax, if intention was limiting search of other search terms in query to some specific site/domain