Question about Ford Crown Victoria

3 Answers

Vehicle came in for check engine light on and running rough,i scanned 1 dtc present p0306 misfire detected cyl #6,the coil had been replace a month earlier same problem,i tested injector pulse with noid light its good,i replaced injector and spark plug,I performed power balance and its still misfiring at idle,but it smooths out at cruise, checked for vacuum leaks,compression test 150psi,vacuum gauge 23hg,no water in oil or plug well,fuel pressure @28psi,fuel filter good not restricted.maybe sticky valves or defective pcm?

Posted by Anonymous on

  • FUBAR Jan 30, 2011

    Have you swapped coils? After market coils are not very good.

×

Ad

3 Answers

dttech

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Superstar:

    An expert that got 20 achievements.

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

  • Master
  • 4,803 Answers

A misfire at idle that smooths out at cruise is ALMOST ALWAYS caused by a vacuum leak. Take a hard look at your fuel trims at idle. If the Bank 2 Long Term Fuel Trim is more than + a couple points higher than the Bank 1 trim, your problem is most likely a vacuum leak. If the Fuel Trims even-out while holding the engine at 2000 RPM for about 20 seconds, then a vacuum leak is DEFINITELY your problem. I would suspect a leaking lower intake gasket leak because an upper plenum leak will normally affect all cylinders.

Posted on Jan 30, 2011

  • dttech
    dttech Jan 30, 2011

    P.S. I have seen several intake gaskes on Fords with cracks in the lower (crankcase) side of the intake manifold runners - you won't find this by spraying carb cleaner on the outside of the manifold.

×

Ad

Anonymous

  • Level 2:

    An expert who has achieved level 2 by getting 100 points

    MVP:

    An expert that got 5 achievements.

    Governor:

    An expert whose answer got voted for 20 times.

    New Friend:

    An expert that has 1 follower.

  • Expert
  • 33 Answers

It sounds to me that your problem could be the pcm you can check if the problem is the pcm by checking with a test light the current in the coil pack connector. there you'll find 3 cables that the light will blink an one that the light will be steady, you will look for the blinking light if u see any difference in the brightness of the bulb in one of the wires that send the signal to the coil pack, then you should check whether the wiring of the computer to the coil package is not open or shorted with a multimeter. if u find that the resistance in the cable is less than 5 ohms then your problem is the pcm

Posted on Jan 30, 2011

Ad

paul pettit

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • Master
  • 383 Answers

You didn't state year or motor size but 28 psi seems a little low for fuel pressure double check specs
other than that i would lead to pcm

Posted on Jan 30, 2011

  • dttech
    dttech Jan 30, 2011

    I agree totally that 28 psi sounds pretty low, however, if he is only getting a single cylinder misfire, (no P0300) and no lean Oxygen Sensor codes and the engine cruises good, the problem is most likely not caused by fuel pressure. Wouldn't you agree?

×

Add Your Answer

×

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

2 Answers

Po306code?


Misfire in cylinder #6. Could be bad spark plug, spark plug wire, cop coil, bad intake/exhaust valve, clogged fuel injector or piston/cylinder problem. What's the year, make, model, engine and have you been following the recommended maintenance schedule for new plugs?

Oct 12, 2017 | Cars & Trucks

1 Answer

2006 grand prix gxp 5.3. When you are driving normally it will miss from 50mph and up. When you punch it it doesn't miss a beat. I cleaned the maf sensor and air filter, Plugs were replaced.


It's probably a coil breaking down , have a scan tool hooked up an have misfires checked to see which cylinder is missing .
Ignition Coils
Each ignition coil has an ignition 1 voltage feed and a ground. The engine control module (ECM) supplies a low reference and an ignition control (IC) circuit. Each ignition coil contains a solid state driver module. The ECM will command the IC circuit ON, this allows the current to flow through the primary coil windings for the appropriate time or dwell. When the ECM commands the IC circuit OFF, this will interrupt current flow through the primary coil windings. The magnetic field created by the primary coil windings will collapse across the secondary coil windings, which induces a high voltage across the spark plug electrodes. The coils are current limited to prevent overloading if the IC current is held high too long. The spark plugs are connected to their respective coils by a short secondary wire. The spark plugs are tipped with iridium for long life and efficiency.
Drive it long enough like that (with it misfiring ) the check engine light will flash . This is to warn that a catalytic converter damaging event is taking place . This would also set a DTC - diagnostic trouble code
DTC Descriptors ?€¢
DTC P0300 Engine Misfire Detected


?€¢
DTC P0301 Cylinder 1 Misfire Detected


?€¢
DTC P0302 Cylinder 2 Misfire Detected


?€¢
DTC P0303 Cylinder 3 Misfire Detected


?€¢
DTC P0304 Cylinder 4 Misfire Detected


?€¢
DTC P0305 Cylinder 5 Misfire Detected


?€¢
DTC P0306 Cylinder 6 Misfire Detected


?€¢
DTC P0307 Cylinder 7 Misfire Detected


?€¢
DTC P0308 Cylinder 8 Misfire Detected

Apr 26, 2016 | Cars & Trucks

2 Answers

2001 ford taurus 3.0 v6 code p0306 misfire


code p 0306 is misfire detected no 6 cylinder causes electrics
more likely a bad injector , injector wiring or dirty tip

May 05, 2017 | 1997 Ford Taurus

1 Answer

2001 ford taurus 3.0 v6 code p0306 misfire


Please go to this page for engine misfire causes.

Aug 08, 2012 | 1997 Ford Taurus

1 Answer

Have misfire, code P0316, any ideals? 86,000 miles on


2004 Marauder and 2003-2004 Mustang vehicles built before 12/19/2004 equipped with 4.6L 4V/5.4 4V engine may exhibit a runs rough, lacks power, and engine misfire, prompted by a MIL light and DTC codes P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308, and P0316.
ACTION
Diagnose engine for engine misfire concern. If diagnostics determine an engine misfire which is characterized by leakage through exhaust valve(s), only replace the affected cylinder head(s).
SERVICE PROCEDURE FOR VEHICLES WITH RUNS ROUGH/MISFIRE CONDITION:
1. Perform relative compression check on all cylinders. If abnormal, check cylinder leakage and actual compression for "low" cylinders refer to Workshop Manual (WSM), Section 303-00.
2. If leakage/compression check indicates a valve train concern, per valve train diagnostics in WSM, Section 303-00, replace cylinder head and cam assembly, pipe plugs and timing chain tensioner, per procedure outlined in WSM, Section 303-01.
3. If cylinder leakage and compression tests are inconclusive, perform misfire diagnostic, per TSB 05-22-8.

So

Feb 26, 2011 | 2004 Ford Freestar

2 Answers

2002 ford escape 3.0L DTC P0305and P0306 what would you ck


P0305 - Cylinder 5 Misfire Detected
P0306 - Cylinder 6 Misfire Detected

When a misfire occurs, engine speed will fluctuate. If the engine speed fluctuates enough to cause the Crankshaft Position (CKP) sensor signal to vary, The Powertrain Control Module (PCM) or Electronic Control Module (ECM) can determine that a misfire is occurring.

When is the code detected?
- Engine Cylinder #5 and #6 is Misfiring.

Symptoms:
- Engine Light ON (or Service Engine Soon Warning Light)
- Lack/loss of power
- Hard start
- Engine hesitation

Possible Causes:
- Improper spark plug at cylinder #5 and #6
- Insufficient compression at cylinder #5 and #6
- Incorrect fuel pressure
- The injector circuit is open or shorted at cylinder #5 and #6
- Fuel injector #5 and #6 may be faulty
- Intake air leak at cyli

Possible Solution:
- Perform Injector Service
- Replaced Spark Plug #5 and #6
- Replaced Injector #5 and #6
- Replaced Ignition Coil #5 and #6

Hope helps.

Jan 02, 2011 | Ford Escape Cars & Trucks

2 Answers

The code reads P 306 misfire on cylinder 6. How


A P0306 code means that the car's computer
has detected that one of the engine's cylinders is not firing properly. In this case it's cylinder #6.

Symptoms may include:
the engine may be harder to start
the engine may stumble / stumble, and/or hesitate
other symptoms may also be present

Causes

A code P0306 may mean that one or more of the following has happened:
Faulty spark plug or wire
Faulty coil (pack)
Faulty oxygen sensor(s)
Faulty fuel injector
Burned exhaust valve
Faulty catalytic converter(s)
Running out of fuel
Poor compression
Defective computer

If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.

If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.e. spark plugs). Depending on how long the ignition components have been in the car, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, distributor cap, and rotor (if applicable). Otherwise, check the coils (a.k.a. coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors.

Feb 15, 2010 | Dodge Durango Cars & Trucks

3 Answers

Engine light flashing


It sounds like you have a misfire. Anytime a misfire is detected by the powertrain control module (PCM) it flashes the check engine light (CEL) on and off. Do not drive it this way because it won't take long to damage the catalytic converter. Have the diagnostic trouble code (DTC) read with a scan tool or "code reader" to see what DTC or DTCs are set. If it's a 4 cylinder, it will have a P0301 set for a cylinder # 1 misfire, a P0302 for a cyl # 2 misfire & so on. If the misfire is random (ocurring in multiple cylinders intermittently) it will have a P0300 set. Once you know which cylinder is misfiring you can check that cyl to see what the cause might be. It could be an ignition coil or spark plug failure. The # 1 cyl is always the one closest to the front of the eng or this car, the one closest to the passenger side fender.

Dec 16, 2008 | 2005 Chevrolet Cobalt

Not finding what you are looking for?
Cars & Trucks Logo

Related Topics:

333 people viewed this question

Ask a Question

Usually answered in minutes!

Top Ford Experts

Marvin
Marvin

Level 3 Expert

85239 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22485 Answers

Jeffrey Turcotte
Jeffrey Turcotte

Level 3 Expert

8984 Answers

Are you a Ford Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...