02 taurus 3.0 vulcan INTERMITTENT PROBLEM

[swilliamsaz]

Hoping SOMEONE can shed some light...
History:
5-6 months ago:
shortly after bought car:
replaced spark plugs, wires, pcv valve, fuel filter, cam shaft syncrho

Fast forward to few weeks before Holidays:
Car started to idle rough, surge in reverse and miss in drive, only on cold start up or after car sat for 20 or more minutes. After several days CEL came on: misfire #1 and P0316- Misfire first 1000 revolutions.
Opened hood at night saw blue corona. Checked plugs, all okay, swapped out wires with old ones. Cleared codes. Car ran better for 1st day. Then, same issue, CEL light a day later, same codes.
Took to pepboys: $90 diagnostic... Recommended new plugs and wires, and possible lean condition in injector 1.
Replaced plugs and wires, cleared codes. No change in symptoms, CEL light on 2 days later.
Car starting to get worse. A few days later, would start to miss at stop light intermittently. CEL Light goes OFF.
2 days ago, cleaned IAC valve, checked coil pack for cracks, sprayed with water, nothing...
Now, still no CEL, car runs VERY rough in reverse when cold, improves somewhat when warm, misses intermittently at stoplights, ever so slight change in RPMs, now misses intermittently under various driving and load conditions.

PLEASE HELP!!! FRUSTRATED and don't want to throw money!!!

[serge_saati]

I passes through the same way. Same code, and it was intermittent too. Exact same symptoms. But in my case it happened when engine is hot. It was the camshaft sensor. Although I replaced the whole thing 6 months before the symptoms (cause squeezing noise) the camshaft sensor was still bad. Cam sensors on these cars never last. They're too sensitive too heat and engine speed. Especially when you rev up quickly.

I think either your camshaft sensor need to be replaced, or synchronizer re-aligned.

When you press on gas and engine sputter w/o responding to gas pedal while driving, it means that engine doesn't receive enough fuel. Camshaft sensor signal is highly required for proper fuel injectors synchronization, especially in a SFI system.
If you press too much gas pedal to go faster, the PCM may receive cam signal by the time, injectors time on will increase at good moment, and you will surge by burning too much fuel suddenly.

If you want to confirm the diagnosis, backprobe cam sensor with a voltmeter or frequency meter while driving. You need long wires extension. And compare signal when you have problems and when you don't.

[swilliamsaz]

UPDATE; Car threw codes again this AM! P0301 and P0316... same as always!!! UGH... This time got DTC Freeze Frame info... Just have no clue what it all means: Here it is:

DTCFRZF P0316 obviously this is code
FUELSYS1 CL unknown
FUELSYS2 N/A? unknown
LOAD_PCT (%) 83.5 unknown
ETC (F) 174 Electronic Temp control?
SHRTFT1 4.7 unknown
LONGFT1 5.5 unknown
SHRTFT2 8.6 unknown
LONGFT2 6.3? unknown
FRP (PSI) 39.6 Fuel Rail Pressure
RPM (/MIN) 2025 Revs per Minute
VSS (MPA) 9 unknown

Can anyone help dicipher and make sense and maybe point to issue? Could it be bad injector, or more of a cam sensor?

[shorod]

Originally Posted by swilliamsaz

UPDATE; Car threw codes again this AM! P0301 and P0316... same as always!!! UGH... This time got DTC Freeze Frame info... Just have no clue what it all means: Here it is:

DTCFRZF P0316 obviously this is code
FUELSYS1 CL Closed Loop
FUELSYS2 N/A? Not Applicable for your car
LOAD_PCT (%) 83.5 Engine load at time of code
ETC (F) 174 Engine Coolant Temperature in degrees Fahrenheit
SHRTFT1 4.7 Bank 1 Short Term Fuel Trim
LONGFT1 5.5 Bank 1 Long Term Fuel Trim
SHRTFT2 8.6 Bank 2 Short Term Fuel Trim
LONGFT2 6.3? Bank 2 Long Term Fuel Trim
FRP (PSI) 39.6 Fuel Rail Pressure
RPM (/MIN) 2025 Revs per Minute
VSS (MPA) 9 Vehicle Speed Sensor (MPH)

Can anyone help dicipher and make sense and maybe point to issue? Could it be bad injector, or more of a cam sensor?

Definitions for the unknowns in blue above. The fuel trim numbers would suggest the PCM is attempting to compensate for what it believes is a slightly lean condition. Per the factory service manual your fuel pressure should be 50-56psi. Since your fuel pressure appears low and the fuel trim numbers suggest the mixture is lean, I'd suggest you first start by changing the fuel filter and check the fuel pressure again. If it's still low, the problem may be your fuel pump. It's more common for fuel pumps to fail as they warm up (running for a long time or hot fuel temperature), then work again after they have time to cool, but I've heard of them failing like you suggest too.

I'd also suggest if you're going to the work of changing out the plug wires, change them with new wires rather than old wires. If they are "used" you replaced them for a reason, right? Either because they had an issue or you didn't trust them to not have any issue soon.

-Rod