01 p351 and 352 with fuel system "open"

[Marissa01]

My 01 v6 runs really rough, missing on cylinders 1 and 4, and the scanner shows that the fuel system monitor is "open" or "open2". Sometimes this lasts 30 seconds or 2 - 3 minutes.

But once the fuel system monitor changes to "closed" everything is great.

Codes P0351 and P0352 keep showing up.

Any ideal on how to make it run right all the time?

 

[MustangLX-5.0]

I'm doubting a faulty coil pack. Reason being is that you say it starts to run fine after couple min. Open/open2 usually refers to bank 1 or bank 2 ( left or right side). I would check the wiring that goes to injectors 1 and 4. You should be able to find them by looking just behind the EGR valve in front. Follow the chrome looking fuel rail where it goes under the upper intake plenum. The first 2 injectors are cylinders 1 and 4. Make sure the plugs aren't loose and that the wiring doesn't have a cut in it. FYI - I'm not sure if you are real familiar with the engine parts, but just in case... the upper intake plenum is the very top of the engine with the 6 - 90 degree arms ( intake runners) bending down left and right. You might also want to check the spark plug wires going to cyl 1 and 4. Make sure they are securely connected to the coil pack and also on the plugs. Just to rule that out.

If you need more info, just rep.

 

[wmburns]

P0351 P0352 ignition problem/bad coil pack

My 01 v6 runs really rough, missing on cylinders 1 and 4, and the scanner shows that the fuel system monitor is "open" or "open2". Sometimes this lasts 30 seconds or 2 - 3 minutes.

But once the fuel system monitor changes to "closed" everything is great.

Codes P0351 and P0352 keep showing up.

Any ideal on how to make it run right all the time?

Codes P0351/P0352 deal directly with a failure in the Primary/Secondary ignition circuit. This could be the coil pack, spark plug wires, the wiring to/from the coil pack.

Cylinders #1 and #4 are on different coil drivers. Start by inspecting all connections to/from the coil pack. Are the spark plug wires in good shape? Do you have spark at all cylinders?

IMO, the source of the DTC's needs to be addressed first. This is an ignition problem and the coil pack should be throughly reviewed. Since the problem comes and goes, suspect a loose connection.

Note, the PCM is running in open loop mode because of the DTC. Once the ignition problem goes away, the PCM switches into closed loop. So, it does not run better because the PCM switches from open to closed loop. It runs better because the quality of the spark improves.

>>>From Ford Service CD
P0351 Through P0360 - Ignition Coil A through J Primary/ Secondary Circuit Malfunction

Each ignition primary circuit is continuously monitored. The test fails when the PCM does not receive a valid IDM pulse signal from the ignition module (integrated in PCM).

Open or short in Ignition START/RUN circuit
Open coil driver circuit in harness
Coil driver circuit shorted to ground
Damaged coil
Damaged PCM
Coil driver circuit shorted to PWR

 

[MustangLX-5.0]

The only reason I brought up the injectors is that those 2 codes tend to show up at times when there are faults in the injector wiring. It sets those codes off sometimes because the cylinders miss from the injector not opening. The coil fires but the cylinder does not respond. I have seen this on 2 other 3.8's. Once the injector problems were fixed, the codes went away and it ran fine all the time. It may very well be a problem with the PCM, or the primary wires going into the coil pack. A bad wire or plug wont set those codes off. A bad plug or plug wire would set off codes P301 - 306 (in a 6 cylinder) for MISFIRE ON CYLINDER #X.

 

[MustangLX-5.0]

DELETE - Double Post from slow azz server

 

[Marissa01]

Correction - missing on 1 and 5. Even though there appears to be plenty of spark, the car misses so bad it cannot be driven. But, again, once the loop closes it runs great.

Switched coils (used) and the car revs freely in Park or Neutral. However, when driven it feels like it has a miss (doesn't runs as good as the other coil).

Two coils and two different problems. Are both coils bad or could this be a sign of something else?

 

[wmburns]

Test coil pack

Suggest confirming the injectors. Use a noid light style tester. Test the fuel injector and confirm firing pulse on each fuel injector. May even consider swaping injectors alternate cylinders to see if the misfire follows the injector.

1 & 5 are on the same coil driver. This could be a bad coil pack. Confirm spark from all cylinders. Check the plug wires as well. Use the tester to confirm low voltage firing pulse to each section of the coil. If any doubt about the condition of the plugs and plug wires, suggest changing them. New plugs/wires are much cheaper than a new PCM.

Note, my $$ is on old/weak plug wires allowing the spark to escape causing interference with other systems.

You need to confirm the wiring back to the PCM. Once the wiring is confirmed good and the coil pack is confirmed good and still no spark in 1/5, the only option left is a bad PCM coil driver.

Low voltage V6 coil pack wire colors:
1/5 DB/LB
3/4 RD/LB
2/6 PK/WH

Check out the following thread on how to diagnose a bad PCM coil driver:
http://www.stangnet.com/mustang-for...code-0352-ign-coil-primary-circuit-fault.html

 

[Aeroman]

Sounds to me like a coil driver problem or primary coil wire/connection problem ( most likely), chance of 2 faulty coil packs with same coils defective is very unlikely.
Noid light test to injectors is a good idea although the pulses are independant, not like the coil driver pulses! My money is on the Primary ignition circuit fault at the moment.