Resolved 1g running SUPER rich

[xander123]

1990 talon tsi, about 12.5 psi of boost right now.
it started fine before but now it really struggles to start, flashing check engine light said it’s the barometric sensor. I cleaned my 3in gm maf, and changed plugs. BUT even before that, the car runs really rich, for no reason. it ran fine before but now ive seen my afr go to 8.1-8.6, and even 7.? at WOT. I was wondering if anyone had any ideas so I dont blow this car up? I also have an exhaust leak and was wondering if that would make the sensors practically useless? I saw someone else saying that a bad o2 sensor could lead to running rich and a cel

550cc injector
small 16g
3in gm maf

I also pulled the spark plugs, they were pitch black. also it has the 255 walbro

 

[habitatguy187]

I would start with the mas wiring since it's throwing a cel for barometric sensor. If the wiring is good then test the mas. And yes exhaust leaks will affect things but they won't make the cel flash

 

[xander123]

I would start with the mas wiring since it's throwing a cel for barometric sensor. If the wiring is good then test the mas. And yes exhaust leaks will affect things but they won't make the cel flash

my car doesnt have a mas, all the wires are cut. pretty sure the gm maf acts as a barometric sensor as well. ive cleaned the maf and ive looked at the wiring, everything looks good. but when looking at the translator, the red and green led flash once when I turn on the battery but disappear a second later. is that normal or do you think my wiring has come loose at some part and isnt getting a solid connection for power? after cleaning the maf my car wont start but I have fuel and spark and air

 

[xander123]

spark plug wire had a tear in it. shorted out and cause my misfire, replaced wires and starts up fine now. also runs with a proper afr

 

[AWD-Tony]

Makes sense. Unburnt fuel passing through. This had a miss at idle so a cylinder drop test would be where I’d start. Glad you fixed it