V6 (1994-2004) Mustangs Technical discussions on the 3.8L and 3.9L V6 torque monsters

Run super rich and misfiring in cyl 6 please help

Thread Tools
 
Search this Thread
 
Old 08-27-2013, 11:15 PM
  #11  
Mustanggirl23
Thread Starter
 
Mustanggirl23's Avatar
 
Join Date: Aug 2013
Location: Oregon
Posts: 9
Default

I have heard somewhere that if you unplug the MAF sensor your car should die, is this true? If not, is there a way to test this? I will also double check my spark plugs. I made sure they were capped correctly before installation but will check again.
Mustanggirl23 is offline  
Old 08-27-2013, 11:29 PM
  #12  
jthorn9
The Godfather
 
jthorn9's Avatar
 
Join Date: Sep 2005
Location: Temple, Texas
Posts: 15,481
Default

Yes, about the MAF. Just think of the MAF as an electronic carburetor. Unplug it and the car will not run under load. However, it can still function and be sending bag info to the ECU.

One thing I over looked is you mentioned the "misfire" is on cylinder 6. How do you know this for sure?

Last edited by jthorn9; 08-28-2013 at 09:16 PM.
jthorn9 is offline  
Old 08-27-2013, 11:46 PM
  #13  
Mustanggirl23
Thread Starter
 
Mustanggirl23's Avatar
 
Join Date: Aug 2013
Location: Oregon
Posts: 9
Default

The error code is P0306. That's the only code given on the OBD2 reader. I unplugged my MAF sensor and the car still runs. I need to rerun my code reader to see if the same error code will pop up, but I can't run codes until tomorrow. So I'm hoping the new plugs, wires, and coil have fixed the cylinder 6 misfire and that the MAF sensor is my culprit.
Mustanggirl23 is offline  
Old 08-28-2013, 09:14 AM
  #14  
RyansQuick6
Reverse Gear Member
 
RyansQuick6's Avatar
 
Join Date: Dec 2006
Location: Baton Rouge, LA
Posts: 8,130
Default

Name:  im-out_zpsa209d188.gif
Views: 1249
Size:  2.74 MB

Last edited by RyansQuick6; 08-28-2013 at 09:19 AM.
RyansQuick6 is offline  
Old 08-28-2013, 12:54 PM
  #15  
Mustanggirl23
Thread Starter
 
Mustanggirl23's Avatar
 
Join Date: Aug 2013
Location: Oregon
Posts: 9
Default

Jthorn9- thank you for your help so far. I am still waiting for my code reader to be returned and am going to rerun the code tester as soon as it gets here. I appreciate your patience and knowledge.

I will let you kno what code pops up after I run the diagnostic again.
Mustanggirl23 is offline  
Old 08-28-2013, 09:20 PM
  #16  
jthorn9
The Godfather
 
jthorn9's Avatar
 
Join Date: Sep 2005
Location: Temple, Texas
Posts: 15,481
Default

One edit to my above post, unpluging the MAF will not cause the car to not run, it will run as at idel the ECU is preset to run at a idel however it would be unable to run properly under load.

Ryan and I listed the most likely fixes for that code. However I did look up the code specifically and here is the list of solutions:

Faulty spark plug or wire Faulty coil (pack)
Faulty oxygen sensor(s)
Faulty fuel injector
Burned exhaust valve
Faulty catalytic converter(s)
Running out of fuel
Poor compression
Defective computer

So if it was doing this before and after the head gasket fix you can knock off a few things. You said you did the plugs, wires, and pack, so that's a check on that one. I mentioned the O2 sensors which I believe to be the likely area with the first three out the way.

Burned exhaust valve is very possible if you didn't have the heads fully inspected.

Faulty cats are possible, however you would usually get other codes from the O2s.

You're obviously not out of fuel so ignore that one.

You ran compression so you know it's not that.

Defective computer is extremely unlikely, I would still put the blame on all the other things I listed, on and not on this list, before I'd think the ECU. As stated the ECUs only go out of they're hit, dropped, or get wet. Very rarely do they ever short or have a circuit failure. It's possible but very unlikely.

Last edited by jthorn9; 08-28-2013 at 09:24 PM.
jthorn9 is offline  
Old 08-28-2013, 09:35 PM
  #17  
jthorn9
The Godfather
 
jthorn9's Avatar
 
Join Date: Sep 2005
Location: Temple, Texas
Posts: 15,481
Default

One thing just popped into my head. You may want to look over your connections very, very carefully. I'd also go as far as to replace the spark plug wire (or swap the wires with cylinder 5) to see if the issue jumps.

Reason I say this is you could have just gotten a bad wire right out the pack. Do the same with the spark plugs just to test.

Also look over the harness and more specifically the plug that plugs into the fuel injector on cylinder 6. Look for any exposed wire, pinching, or any other sign of damage. Basically if the harness is damaged by that fuel injector connector it could be causing the problems. Very unlikely but something to look at.

Eliminate the easiest things first.
jthorn9 is offline  
Old 08-29-2013, 10:41 AM
  #18  
Mustanggirl23
Thread Starter
 
Mustanggirl23's Avatar
 
Join Date: Aug 2013
Location: Oregon
Posts: 9
Default

So I ran my codes and am getting the P0306 and a P0113.
I went out to my car last night and was looking over wires, when I shut down my light and someone started the car I noticed a spark that I couldn't see during the day. I started wiggling the spark plug wires while the car was running an it would spark as soon as it touched anything else. So I'm assuming by this that I was given a faulty wire and am going to take this set back. I did some research and think that I'm going to upgrade to a performance set.
Mustanggirl23 is offline  
Old 08-29-2013, 12:24 PM
  #19  
Daehawk
4th Gear Member
 
Daehawk's Avatar
 
Join Date: Mar 2010
Location: TN
Posts: 1,626
Default

I recommend MSD wires or at the least Motorcraft.
Daehawk is offline  
Old 08-29-2013, 09:11 PM
  #20  
jthorn9
The Godfather
 
jthorn9's Avatar
 
Join Date: Sep 2005
Location: Temple, Texas
Posts: 15,481
Default

BAM!!! There you go, just as we stated it was an ignition problem. Remember, when these issues occur always rule out the easiest things first before moving onto more odd ball things.
jthorn9 is offline  


Quick Reply: Run super rich and misfiring in cyl 6 please help



All times are GMT -5. The time now is 03:50 AM.