Engine misfire?

Hi

Yes injector will cause the condition try some Techron made by Chevron in tank see if there is some improvement. Due to the intermittent nature injector maybe dirty and not allowing fuel to flow. Which will give lean code bank 2. if it was an ignition issue the unburnt fuel would enter exhaust and create a rich condition. I would clean the MAF sensor and then follow this guide.

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

Please run down this guide and report back.

My car has a skip. Things I have replaced on it

1. alternator
2. Intake manifold with thermostat
3. Eight new ignition coils
4. New battery
5. New water pump.

What could it be?

Have you done the spark plugs with the ignition coils? I would change those out. Here is a guide that will help you.

https://www.2carpros.com/articles/how-to-change-spark-plugs

Please let us know what you find so it will help others.

Best, Ken

When I bought the car in December I got a full tune up including new spark plugs so I mean it's time to get new ones again??

No the plugs should be okay, we need to do a compression test to see if you have any low cylinders. Here is a guide that will help you.

https://www.2carpros.com/articles/how-to-test-engine-compression

scan for codes and check fuel pressure with a gauge auto parts rent it. also check for a vacuum leak like hoses/ etc.
https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Ignition coils are very common to fail but will not set misfire codes unless it is severe enough. If you can get a good scanner where you could see MOD 6 data then this is how you check to see if you have a cylinder misfiring.

Go to MOD6 and go to Test Id $53 Next screen will have the component numbers. $00-$0A That would be cylinders 1-8 Click on each one, one at a time and record the recorded misfire counts. If you see one cylinder higher then the rest then swap that cylinder coil with one that shows no misfires. Reset the computer and road test again until it acts up a few times. Recheck your MOD6 data and if the counter jumped to the new cylinder you installed the coil too then your coil is defective.


You can also do that with spark plugs and fuel injectors. But I believe if you do have a slight miss especially under load, then I suspect you will find a bad coil using the information I gave you. Good luck to you and let us know how you do,

Please get back to us with what you find and thank you for visiting 2CarPros.

Renee
Admin

All 8 could are brand new

It is a starting point I am directing you too. Have seen defective coils before but as stated earlier you can do the same tesy with plugs and fuel injectors.

But first you need to look at the data I pointed out to see if you do have a misfire? If you do not have a scan tool to provide Mod 6 data then you should take it in to your local shop for proper diagnosis.

Transmission problem V8 Two Wheel Drive Automatic 101,00 miles

Hello,

When I accelerate in my 2001 Lincoln Town Car, it jerks constantly. It is worse up hill, but also does it on level roads. The oil and transmission fluid / filters have been changed at factory recommended intervals. Besides that, the car runs fine. 4.6 V8 with a bit over 100K. Car has been babied - this has been going on since the beginning of summer.

Any ideas?

Thanks
[email protected]

Hi [email protected],

Jerking during acceleration are mostly engine performance related and likely to be due to spark plug and/or related problems.

Here is a video to help you see what you are in for when changing the plugs.

https://youtu.be/E6oier7agkY

If the Check Engine Light is indicating, get a scan done to retrieve for trouble codes and let me know what they are.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Please let us know what you find. We are interested to see what it is.

Cheers

Thanks for your reply. There is no check engine light.
Do you recommend that the coils and spark plugs be changed? The plugs were changed @ the last tune up but I think they broke one because when I changed all of them again the problem went away and the truck runs great.

Thanks, [email protected]

Spark plugs would be difficult to test, only visual inspection for signs of shorting.

The ignition coils can be tested for resistance specifications. Check for oil or water contamination in the spark plug tubes.

Check for loose wire couplers.

If you have not solved this problem, I have had the same problem on 5 diferent Ford full size cars with 4.6 engine. I fixed all of mine by installinf new spark plugs and connector springs with boots. I spite of claims I have not had any plugs go 100K before causing an engine miss. A mechanic told me the boots were bad to leak spark by the time the plugs needed replaced. I now change the boots when I change the plugs because they are only about $35. per set at NAPA and easy to change when you change the plugs. If you do the job yourself make sure you blow out the plug holes before removing the old plugs and before putting the new boot into the hole.
Hope this helps.

I have had a misfire on cylinder 4 since I purchased the car. I have replaced all plugs and coils with Motorcraft parts. Have swapped injector 4 with 2 and no change. The misfire is not consistent but when has a miss it always shows to be in cylinder 4. Any suggestions on where to go from here would be appreciated.

Based on mileage and what you have already done, I would recommend checking engine compression. If the compression is more than 10% lower than the highest reading, it can cause a misfire. Also, have you checked fuel pressure?

Here are a few links you may find helpful:

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

https://www.2carpros.com/articles/how-to-test-engine-compression

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Let me know what you find or if you have other questions.

Joe

Thank you. I will give this a try.

You are very welcome. If you get the chance, let me know what you find. Additionally, here are the directions specific to your vehicle. I said 10% difference is an issue, but the attached directions indicate 25%. This information is right from the Alldata manual.

_______________________________-

2000 Lincoln Town Car V8-4.6L VIN W
Compression Test
Vehicle Powertrain Management Tune-up and Engine Performance Checks Compression Check Testing and Inspection Component Tests and General Diagnostics Compression Test
COMPRESSION TEST
AllData Editors Note - Ford does not provide a cranking pressure specification, only an acceptable range.

General Remarks

Note: Removing fuses and disconnecting electrical components causes the powertrain control module (PCM) to log an error message. After the measurements have been carried out this error message should be cleared from memory by connecting to PDU.

Note: Only check the compression pressure with the valves set to the prescribed clearance (if this can be adjusted).

The compression pressure should be checked with the engine at operating temperature.

Check The Compression Pressure

WARNING: On manual transmissions shift the transmission into neutral. On automatic transmission vehicles, select "P". Failure to follow these instructions may result in personal injury.

1. Remove the fuel pump relay.
2. Start the engine - the engine will start, run for a few seconds then stall.
3. Remove the spark plugs.
4. Install the compression tester.
5. Install an auxiliary starter switch in the starting circuit. With the ignition switch OFF, using the auxiliary starter switch, crank the engine a minimum of five compression strokes and record the highest reading. Note the approximate number of compression strokes required to obtain the highest reading.
6. Repeat the test on each cylinder, cranking the engine approximately the same number of compression strokes.
7. Install the components in reverse order, observing the specified tightening torques.
8. Reset the PCM fault memory.

Interpretation of the Results
The indicated compression pressure are considered within specification if the lowest reading cylinder is within 75% of the highest reading.

CAUTION: If engine oil is sprayed into the combustion chamber, after carrying out the measurement run the engine at 2000 rpm for about 15 minutes, in order to burn the oil and prevent damage to the catalytic converter.

If the measurement on one or more cylinders is much lower than the specified value, spray some engine oil into the combustion chamber and repeat the compression measurement.

If the reading greatly improves, the piston rings are damaged.

If the reading stays the same, the cause is either damaged valve seats or valve stem seals.

If the measurements for two cylinders next to each other are both too low then it is very likely that the cylinder head gasket between them is burnt through. This can also be recognized by traces of engine oil in the coolant and/or coolant in the engine oil.

____________________________________________

If you have the chance, let me know what you find.

Take care,
Joe

My car has shown lean conditions. It may not start on the first and second try. Now getting a random misfire. Car runs okay over forty mph. About eighteen months ago changed plugs and coils. Cleaned throttle body and EGR and replaced IAC. Still misfiring.

Sure it could if the compression is below like 90 psi but the misfire on that cylinder would most likely be there all the time and not get better over 40 mph.
I think you should first try to narrow it down to which cylinders are misfiring, when and then why.
You should start with removing all the spark plugs, remember where they came from and see/smell if any smell like gasoline or motor oil or if any have motor oil, gasoline or even coolant on them. If so, that is probably the cylinder that is misfiring.
Was the P0300 the only code?

Yes p 300 was the only code.

Okay, let me know after you remove the spark plugs and see/smell what they are like and if you do have a compression tester, go ahead and test all of the cylinders.

My Towncar is missing on #1 & 5 cylinders. I had a bad tank of gas. Drained the gas put new in and have had this problem. The shop says it has no compression on 1 & 5. It was dripping some water and vapor from the exhaust. Did not have any antifreeze in it. Any thoughts?

If you are in a warm climate area such as Florida or any other states where freezing temperatures do not take place you do not need antifreeze .. however antifreeze mixed 50/50 is better for your complete cooling system than pure water. 126,000 miles on a 4.6L V8 is really not bad at all. No compression on cylinders 1 & 5 could possibly be bad exhaust valves on #1 and#5. If you hear a popping sound from within the engine it very well could be a intake valve. If you hear a popping sound from your exhaust it very well could be a exhaust valve. If you are seeing white steam coming out of you exhaust you could have a cracked head gasket. The 4.6L Firing order is 1-3-7-2-6-5-4-8 so that would possibly mean both head gaskets are bad because cylinder 1 (Standing in front of vehicle looking toward the windshield is on your "left side" of the engine and cylinder 5 (Standing in front of vehicle looking toward the windshield is on your "right side" of the engine. (See Diagram Below)

Usually the crack in the head gasket would be right above or close to a specific cylinder where the coolant can enter and create steam when burned up by combustion, and exit through the exhaust. I strongly feel the engine with 126,000 miles does not have bad head gaskets unless you overheated the engine and continued driving it. I would advise you find another shop and see if they tell you there is no compression in cylinders #1 and #5. Usually a misfire is often solved by cleaning the M.A.F. (Max Air Flow) Sensor with spray Electronics or carb cleaning solution. Mak sure it is completely dry before putting it back on. Hopefully that will solve the problem of #1 and #5 misfire. Good Luck; Rick

EASY FIX!!

So I've had the problem myself in the past and there's often a simple solution that MANY are strangely enough overlooking. If any work was recently performed on the car or if the battery went dead/was changed, then an idle relearn procedure MUST be performed. If this is not performed A Lean Bank 2 trouble code will emerge.

1. First begin by draining the PCM capacitors of any learned values via disconnecting the wire harness from the negative terminal, placing an insulating rag between it and the negative battery terminal, then applying a jumper wire to the positive lead battery terminal and the other end of the jumper wire to that of the wire harness otherwise connected to the negative battery terminal.

2. Allow about a minute or so for the draining procedure to complete, then remove the jumper wire first from the negative wiring harness and then the positive battery terminal.

3. Then replace negative/ground wire harness to the negative battery terminal to reestablish completion of the normal car electrical circuit.

4. Make sure all accessory items (head lamps/air conditioning/etc...) are off and place your key in the ignition.

5. Turn the key to the ON position and wait for your dash indicator lamps to clear, then start the ignition on the car.

6. Allow the car to idle from a cold start until it's fully warmed up. Then allow another 5-10min for the PCM to fully calibrate and store the throttle position at idle (a total of 15-20 min altogether (10min from ignition start + 5-10min post warm up =15-20min total).

7. Once these parameters have been properly stored within the PCM drive your car normally on the road for a while that it might calibrate the full range (throttle position at various accelerations and speeds + vital gear shifting points) of key throttle points.
(*note: I'd recommend clearing the code before attempting this, though not wholly necessary.)

¡¡EASY FIX!!

So I've had the problem myself in the past and there's often a simple solution that MANY are strangely enough overlooking. If any work was recently performed on the car or if the battery went dead/was changed, then an idle relearn procedure MUST be performed. If this is not performed A Lean Bank 2 trouble code will emerge.

1. First begin by draining the PCM capacitors of any learned values via disconnecting the wire harness from the negative terminal, placing an insulating rag between it and the negative battery terminal, then applying a jumper wire to the positive lead battery terminal and the other end of the jumper wire to that of the wire harness otherwise connected to the negative battery terminal.

2. Allow about a minute or so for the draining procedure to complete, then remove the jumper wire first from the negative wiring harness and then the positive battery terminal.

3. Then replace negative/ground wire harness to the negative battery terminal to reestablish completion of the normal car electrical circuit.

4. Make sure all accessory items (head lamps/air conditioning/etc...) are off and place your key in the ignition.

5. Turn the key to the ON position and wait for your dash indicator lamps to clear, then start the ignition on the car.

6. Allow the car to idle from a cold start until it's fully warmed up. Then allow another 5-10min for the PCM to fully calibrate and store the throttle position at idle (a total of 15-20 min altogether (10min from ignition start + 5-10min post warm up =15-20min total).

7. Once these parameters have been properly stored within the PCM drive your car normally on the road for a while that it might calibrate the full range (throttle position at various accelerations and speeds + vital gear shifting points) of key throttle points.
(*note: I'd recommend clearing the code before attempting this, though not wholly necessary.)

Hi,

Thank you for that information. I feel it will help others in the future.

Take care,

Joe