remedial maf question

[g6civcx]

Simple question.

The car idles strangely and bucks and dies. Unplug the MAF and it idles somewhat okay. Plug in the MAF and the idle goes straight to 2-3000 RPM and then dies.

I have not done the MAF voltage check yet but will do it as soon as the weather clears up.

[Om1kron]

bad maf... i have the same problem, even if you're not getting black death smoke. it's working at 20 percent.

[g6civcx]

There is black smoke out the tailpipe. The car ran ok last Thanksgiving so he doesn't believe that the MAF is bad. He doesn't believe me that MAFs go bad all the time, especially with all the bad weather we had.

[rb25s13vert]

you could try maf cleaner but its probably no good...

[codyace]

bad maf... i have the same problem, even if you're not getting black death smoke. it's working at 20 percent.

my lil grasshopper, with the headline news

[Om1kron]

my lil grasshopper, with the headline news

seriously, I have a maf on my car with a crack, no black deathsmoke... but it wont go past 4 grand without backfiring and it smeeels of gasoline in my garage.

if it shoots to 2 grand for your idle then bam it's bad, it may let the car idle normally now and then but dude it's bad trust.

[g6civcx]

seriously, I have a maf on my car with a crack, no black deathsmoke... but it wont go past 4 grand without backfiring and it smeeels of gasoline in my garage.

if it shoots to 2 grand for your idle then bam it's bad, it may let the car idle normally now and then but dude it's bad trust.

I will do the voltage check today and see if it's really the MAF.

[codyace]

seriously, I have a maf on my car with a crack, no black deathsmoke... but it wont go past 4 grand without backfiring and it smeeels of gasoline in my garage.

if it shoots to 2 grand for your idle then bam it's bad, it may let the car idle normally now and then but dude it's bad trust.


Yea man, that little element can be a mofugga...that's why I said that before...they are so simple, yet any difference can fubar them. Heck on mustangs, even spinning them radially on an intake can make them run odd!

[smelly240]

more likely is that the wiring is the issue... Not that the mafs dont go bad - but when u dont have the stock airbox keeping the maf in a fixed place (plus the engine and harness always moving) - the wires tend to break

[g6civcx]

more likely is that the wiring is the issue... Not that the mafs dont go bad - but when u dont have the stock airbox keeping the maf in a fixed place (plus the engine and harness always moving) - the wires tend to break

Also a possibility. I checked the pigtail and wired it up myself, but you never know.

I don't like how the filter just flops around.

[AKADriver]

You should add that we checked the TPS and idle air controller on this car and it was fine. We also checked for vacuum leaks. I agree that it's the MAF or the MAF harness, though I saw no breaks in the harness.

[g6civcx]

Swapped MAF with a known good and it's still the same.

I think it's the wiring or the ECU at this point.

[steve shadows]

sounds like the wiring to the maf

[g6civcx]

I checked every single sensor for voltage and everything looks like it's ok. I finally gave up and decided to pull the harness.

When pulling the harness out, I noticed that the #4 fuel injector wire was shorted to ground.

The #4 cylinder is pretty much flooded with fuel all the time. Eery time the spark plug fires there's a ton of fuel in the #4 cylinder. That would make the car rev up high and eventually stall when the ECU registers a misfire.

When it doesn't rev high it would buckle because the #4 injector is causing a misfire.

When I unplugged the MAF, the ECU only fires #1 and #2 cylinders. It can idle with the MAF unplugged forever without stalling.

When I plugged the MAF back in it would rev up high because the #4 cylinder is pretty much flooded. Then it would die after that.

Trying to keep the engine running with the throttle makes the car run really rich since #4 is pretty much dumping fuel

Let me know if I'm crazy.