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

V6 misfiring + bad lack of power

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Old Mar 10, 2006 | 11:24 AM
  #1  
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stangmike
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Default V6 misfiring + bad lack of power

Hi Stang Fan,
I’m stunk with a weird problem that I didn’t find any solution on the Forum for it! I have a 1995 Mustang V6 with automatic transmission (180 000 km) and it’s been 3 months now that the engine is misfiring or idle rough + terrible lack of power. It all started with the car sitting in the garage for about 2 weeks without moving (was off on vacation). When we came back, the car would start find without any apparent problem and after a couple of minutes it started misfiring and the engine was sacking badly. On top of that the Tach indication isn’t realistic, was getting an RPM of 800 with full throttle applied (in my mind was more up to 3 000 or 3 500 RPM!!!) + the Tach needle was moving up and down eracticly. I went and filled the tank up thinking that some condensation might have happened in the gas tank and I was getting water in the fuel, no luck…same problem!

I then found the spark plug wire were leaking a bit (I’ve change them only 6 months before but they were bad again, got them exchange under the warranty)…no luck again.[:-]
I was receiving an MIL code which a local garage read for me, P0302 (Cylinder 2 Misfire Detected). I’ve changed the number 2 spark plug (which also got replace 6 months ago but sh*t happen!). No positive result. Got the Coil pack and the trigger harness tested and found it ok but desperate to find the solution, I’ve changed the coil pack anyways with a used one (changed it twice actually!) No positive result either. [&o]
I’ve took all the spark plug off and got a compression check done, compression is ok (the previous owner told me that he got the head gasket job done but I wanted to verify if a valve wasn’t stuck!). I inspected the spark plug and found them to all have heavy carbon deposit on them (Soft, black, sooty, dry-looking carbon… not oil deposit!). This is usually a sign of a rich air/fuel mixture or poor misfiring. Having this heavy carbon deposit, it’s easy to see which sparkplug is firing (only one shiny point on the plug were the spark comes out), found that spark plug at cylinder #1 wasn’t firing… replace it…guess what…no change! [:-]
I though maybe the PCM isn’t receiving the correct crankshaft position signal and this is why I have rich air/fuel mixture and bad Tach reading. So I changed the Crankshaft position sensor… no change! [&:]
Seeking for a vacuum leak with a spray bottle with a mixture of water and soap, I found that the fuel injector o-ring where leaking. Change all injector o-ring + plenum intake gasket, also cleaned the air intake, EGR valve (+exhaust connecting tube) and IAC valve with a special cleaner… No changes!!! [:@]
I don’t know what is left to do!!! Change the PCM or the ignition module, maybe the camshaft position sensor?!? Drive the f**king car into a ditch! Did I miss something!!!

PLEASE HELP
Old Mar 10, 2006 | 01:21 PM
  #2  
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Autobadges.com
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Default RE: V6 misfiring + bad lack of power

Wow usually its one of those problems....the misfiring is what gets me...hmmm lets bump this for other possibilities
Old Mar 10, 2006 | 02:06 PM
  #3  
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lilnicky068
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Joined: Feb 2005
Posts: 252
From: Da Ville
Default RE: V6 misfiring + bad lack of power

replace your DPFE sensor. you can get them on ebay for about $30. make sure you get the right model.
Old Mar 11, 2006 | 12:01 AM
  #4  
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jthorn9
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Joined: Sep 2005
Posts: 15,480
From: Temple, Texas
Default RE: V6 misfiring + bad lack of power

It's deffinitly a sensor problem, get your maf, ait, and other air sensors checked.
Old Mar 11, 2006 | 12:42 AM
  #5  
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03YellowPony
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Joined: May 2005
Posts: 7,445
From:
Default RE: V6 misfiring + bad lack of power

ORIGINAL: stangmike

Hi Stang Fan,
I’m stunk with a weird problem that I didn’t find any solution on the Forum for it! I have a 1995 Mustang V6 with automatic transmission (180 000 km) and it’s been 3 months now that the engine is misfiring or idle rough + terrible lack of power. It all started with the car sitting in the garage for about 2 weeks without moving (was off on vacation). When we came back, the car would start find without any apparent problem and after a couple of minutes it started misfiring and the engine was sacking badly. On top of that the Tach indication isn’t realistic, was getting an RPM of 800 with full throttle applied (in my mind was more up to 3 000 or 3 500 RPM!!!) + the Tach needle was moving up and down eracticly. I went and filled the tank up thinking that some condensation might have happened in the gas tank and I was getting water in the fuel, no luck…same problem!

I then found the spark plug wire were leaking a bit (I’ve change them only 6 months before but they were bad again, got them exchange under the warranty)…no luck again.[:-]
I was receiving an MIL code which a local garage read for me, P0302 (Cylinder 2 Misfire Detected). I’ve changed the number 2 spark plug (which also got replace 6 months ago but sh*t happen!). No positive result. Got the Coil pack and the trigger harness tested and found it ok but desperate to find the solution, I’ve changed the coil pack anyways with a used one (changed it twice actually!) No positive result either. [&o]
I’ve took all the spark plug off and got a compression check done, compression is ok (the previous owner told me that he got the head gasket job done but I wanted to verify if a valve wasn’t stuck!). I inspected the spark plug and found them to all have heavy carbon deposit on them (Soft, black, sooty, dry-looking carbon… not oil deposit!). This is usually a sign of a rich air/fuel mixture or poor misfiring. Having this heavy carbon deposit, it’s easy to see which sparkplug is firing (only one shiny point on the plug were the spark comes out), found that spark plug at cylinder #1 wasn’t firing… replace it…guess what…no change! [:-]
I though maybe the PCM isn’t receiving the correct crankshaft position signal and this is why I have rich air/fuel mixture and bad Tach reading. So I changed the Crankshaft position sensor… no change! [&:]
Seeking for a vacuum leak with a spray bottle with a mixture of water and soap, I found that the fuel injector o-ring where leaking. Change all injector o-ring + plenum intake gasket, also cleaned the air intake, EGR valve (+exhaust connecting tube) and IAC valve with a special cleaner… No changes!!! [:@]
I don’t know what is left to do!!! Change the PCM or the ignition module, maybe the camshaft position sensor?!? Drive the f**king car into a ditch! Did I miss something!!!

PLEASE HELP
Since you've done all this to no avail, maybe it's time to have a pro check it out.
Old Mar 11, 2006 | 11:55 AM
  #6  
04V6Stang's Avatar
04V6Stang
 
Joined: Feb 2006
Posts: 27
Default RE: V6 misfiring + bad lack of power

I had a similar problem with my 93 GT. Ended up being the MAF sensor. Took a while to figure it out.
Old Mar 11, 2006 | 01:17 PM
  #7  
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tripsevn7
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Joined: Jul 2003
Posts: 4,231
From: New Orleans La
Default RE: V6 misfiring + bad lack of power

maf is bad on my firebird right now which is causing some of the above issues on that car.
Old Mar 11, 2006 | 01:30 PM
  #8  
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98ponycar
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Joined: May 2004
Posts: 331
From:
Default RE: V6 misfiring + bad lack of power

I agree with 03yellowpony. Let a pro handle it. It would have been cheaper, and a lot easier, for you to have taken it to a shop to begin with.
Old Mar 11, 2006 | 02:28 PM
  #9  
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Autobadges.com
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From: Los Angeles, CA (SoCal)
Default RE: V6 misfiring + bad lack of power

Just go to a MUSTANG SHOP not a mom and pop that will try to change out every damn part to make money
Old Mar 11, 2006 | 05:00 PM
  #10  
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jthorn9
The Godfather
 
Joined: Sep 2005
Posts: 15,480
From: Temple, Texas
Default RE: V6 misfiring + bad lack of power

Yea you'll have to take it to a shop, but I'm really sure that something is wrong with your maf, because I had almost the exact same problem with mine about 2 months ago.



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