Ford Taurus The long running mid sized sedan offering sure footed front wheel drive and a roomy interior.

3 ltr DOHC runs rough and has a black smoke

Old 01-01-2012, 08:16 PM
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Posts: 2
Default 3 ltr DOHC runs rough and has a black smoke

OK we have a dohc that will not stay running unless we keep working the foot feet and the PCM does not have the engine light lit. The back exhaust gets cherry red in a short time

we have run a compression test all good
new plugs
ohm out the wires and all good
used coil ( came off a running car )
used mass ( off a running car)
new idle air control
dropped the back exhaust and it did not run any better (looking for plugged cat)

The car appears to be very rich The new plugs are black (not from oil)
dirty stinky smoke in the garage while it runs
we have not put in a new cam sensor on yet.

The plan is to disconnect the battery and let is sit a while so the pcm resets.

Do these things jump time? ( some times it sound like it is poping back into the intake)

is it common for the PCM to go out?

I will listen to any (good) advise as this is new territory for me

Thanks fro the help
Old 01-02-2012, 04:33 AM
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Join Date: Jun 2010
Posts: 9,258

You didn't state what year the vehicle was. Depending on that and a few other pieces, some later year vehicles had a returnless fuel system where the pressure regulator is located on the fuel pump module located in the fuel tank.
If it has the pressure regulator in the engine compartment , remove the vacuum hose and see if gasoline comes out. If the hose has fuel coming out of it , the fuel regulator is defective.
There is a pulsation dampener in some of the fuel supply lines that could be mistaken for a fuel regulator,be careful. Also there is a pressure sensor on the supply lines of some systems that tells the ECM to run the pump in order to maintain the correct pressure. In that system the fuel pump runs faster or slower as directed by the pulse width signal from the ECM.
If you could provide the year of the vehicle and/or trace and check the things mentioned you should be able to pin down the cause.
Old 01-02-2012, 05:36 PM
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The car is a 2001 with the DOHC
Old 01-02-2012, 05:40 PM
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Need to know what engine is in the car and what model . Ford has many different engines in many different models.
Old 01-12-2012, 11:54 AM
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Join Date: Jan 2012
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your post is not clear can i have more stuff please plz in order to help you.
Old 01-12-2012, 04:14 PM
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Location: Yorkshire, NY
Posts: 2,177

You have some conflicting information in your posts.

1st post you state that you replaced the coil and OHM'd out the wires.
2nd post you state that the car has the DOHC.

Since your posting header states "3ltr", you will have one of 2 engines. Either the 3.0 DOHV Duratec engine or the 3.0 OHV Vulcan engine. The 3.0 DOHC Duratec engine uses Coil On Plugs, thus no single coil or plug wires. While the 3.0 OHV Vulcan engine uses plug wires and a single coil.

To identify which one you have, the DOHC engine has the plugs going down thru the valve covers, while the OHV engine has the plugs going into the side of the heads.

Based on this information, please provide which actual engine you have.

Last edited by Use Common Sense; 01-12-2012 at 04:17 PM.
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