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Discussion Starter #1 (Edited)
Started having trouble with the 3.8 engine about a year ago.

Symptoms:

Hesitation

Rough idle

stumbling on the freeway-felt like it's starving.

Then, it started throwing P0316 and P0302 codes-generic miss, miss cyl 2

Replaced the coil block, the cam synchro, the cam position sensor, the crank position sensor.

A mechanic wrote a post that said that bad injectors can cause those codes, so I replaced the injector on cyl 2.

Still getting the damned codes!

When the car runs good, it runs great, but I am still getting the damned codes and the symptoms.

My $59 DTC tester from Harbor Freight does show one interesting thing: when I look at the "freeze frame" the Fuel Rail Pressure reads 0.0 PSI.

Could it be a bad FRS and it's just not throwing that code?

Another symptom: the RPM's won't go above 4,000 and the engine then surges like you are jamming the throttle. It's very regular, about one cycle every 2 seconds.

Driving me nuts. Any help would be greatly appreciated.
 

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Discussion Starter #3
Yep.

---------- Post added at 01:02 AM ---------- Previous post was at 01:02 AM ----------

It's an excellent question, by the way.
 

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well i just ran the codes...the p0302 is a generic miss but the p0316 is a bank 1 o2 code...been there done that on my old GT...had the same issues you're having...a new upstream took care of it for me. i noticed on your list of new parts a new o2 sensor wasn't part of it. did you replace it?
 

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Discussion Starter #5
I haven't replaced the O2 sensor.

Another symptom: the revs won't go above 4,000 and there is a regular surge after that-like the throttle is being regularly opened and closed.
 

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Discussion Starter #6
I am not finding a reference to the P0316 to be a O2 sensor code. I keep finding "misfire detected first 1,000 revolutions.

I did have a problem after changing the clutch-the right side exhaust manifold cracked when I re-attached the exhaust pipe. It's a common problem on that model. It took a while to diagnose-the crack is in an inaccessible spot.
 

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cessnadriver said:
I haven't replaced the O2 sensor.

Another symptom: the revs won't go above 4,000 and there is a regular surge after that-like the throttle is being regularly opened and closed.
At idle? Thats normal. Please list all codes, symptoms, and if you have your VIN that as well and ill pull it up and try to get an answer to your problem(s)
 

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Discussion Starter #8
The car idles rough, like the computer is hunting.

The surging happens at 4, 000 RPM and it's a regular rythem. The engine won't rev higher (this is done with the car stationary and the clutch pedal on the floor or with the stick in neutral)

The codes are always P0316 and P0302. Usually happen after a hot re-start.

Blinking SES light when accelerating on the freeway. Also the engine seems to stumble like it's starving.

I'll have to get the VIN to you later.

Thanks for your help, I do appreciate it! Is there a way to PM you the VIN?
 

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I'd like to know what the results were from this as well if possible, having some of the same symptoms myself, but no codes. Every now an then when sitting at idle the engine will do a dip and roll or just run rough at low rpms. Happens randomly. All I've done so far to troubleshoot was a vacuum leak check around the heads and intake manifolds, didn't come up with nothin.
 

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Discussion Starter #11 (Edited)
The first thing to check on the 3.8 type V6's is the camshaft syncronizer.

It's easy to check. When the bearing goes out it often squeaks, so you can do the ole paper towel roll as stethoscope trick.

You can also easily remove the Camshaft Postion Sensor (looks like a little black cap with a nose) wich sits on top of the synchronizer.

You should be able to remove the sensor for inspection without touching anything else.

The locking tab on the connector is the "pull up" type. A nice long 1/4 in drive extension and a 5.5 mm socket makes short work of removing and replacing the sensor.

Two things to look for:

There is a tooth on the part that goes around-make sure the tooth is good.

If there is any residue in the top of the synchronizer that looks like rust, it's toast. Get a brand new assembly-DON'T buy a cheap one or a rebuild.

It's a very crappy design!

Hope this will help you out.
 

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Discussion Starter #13
There are several videos on YouTube that show the condition of a bad synchronizer.

Make sure you use the little tool if you change the synchronizer-dont try to eyeball it.
 

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cessnadriver said:
There are several videos on YouTube that show the condition of a bad synchronizer.

Make sure you use the little tool if you change the synchronizer-dont try to eyeball it.
What little tool are you talking about?
 

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Discussion Starter #15
There is a small cap, usually made out of black plastic, that you use to align the camshaft synchronizer.

Some of the YouTube videos show people trying to align the synchronizer without the tool.

Two of the synchronizers I bought came with the cap. The link shows the synchronizer and the positioning tool.

Don't cheap out on this part-get a brand new one from Ford or BWD.

CAMSHAFT SYNCHRONIZER 99-06 FORD 3.8, 4.2L | eBay
 

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I know this may sound crazy but check your sparkplugs and wires. I had this same problem in my 04 and this fixed it after I replaced camshaft position sensor and syncronizer.
 

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Also as I stated before, there is a rev limiter at 4k on our model mustangs. So that takes care of your concern about it not revving past that.
 

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Discussion Starter #19 (Edited)
Thanks for your advice. Plugs have been changed and the wires have been checked (Cyl 2 and 6 fire together on each rev, so switching the wires makes no difference-runs the same and the car throws the same codes.)

Checking the old and the new spark plugs after break in shows no difference on the #2 plug from the others.

I really did hope it was a bad plug or wire.
 

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Discussion Starter #20
Funny story about governors-the governor of South Dakota was trying to outrun a forest fire in an Explorer and found out that it stopped accelerating at 99 MPH.
 
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