Engine misfire?

hi yes first thing take truck to exhaust shop ask them to test convertors . this is done with a gauge and back pressure is tested high back pressure restricted .this will eliminate the expensive part.now the coil is a very good suspect. use a multi meter set the meter on ohms. ground one term remove plug wires from coil. probe each terminal on coil. are all the terminals in the same range. if yes coil is good if no coil is bad.good luck write back if you need too

This guide should help us fix it

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

Please run down this guide and report back.

It misfires when idling

Yep, an idle misfire is almost never an ignition problem, it could be a vacuum leak or a mass air flow sensor that needs to be cleaned which controls the fuel mixture. here is information on both, please heck it out and get back to me

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

and

https://www.2carpros.com/articles/mass-air-flow-service

Please get back to us so we can help you

No spark on three and four when tested with HEI spark tester on coil. Have changed out coil pack, plug wires and plugs. Using procedures on easy auto diagnostics.com there is no signal present on pin 1 per their procedure (no light flashing when engine started).

I would like to chase that red wire back to PCM, but would feel more comfortable with a diagram which shows the pin out supporting the ignition function.

Good morning,

I attached the diagram for you of the wires from the coil to the ECM.

I would also consider the crank sensor. That is the sensor that sends a signal to the ECM for cylinder location and to ground the coil so the spark will occur.

https://www.2carpros.com/articles/crankshaft-angle-sensor-replacement

and

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

Have you checked for any codes in the system? Do both the key on, engine off and the engine running check.

Roy

Thank you Roy. after looking at the diagram, I figured out I am an idiot! Having a background in electronics I seemed to ignore what a red wire typically indicates (B+). so, my test had no value. I am going to start over and pull codes for key on, engine off and the engine running check.

I noticed the wire colors on diagram do not match those on my vehicle. starting with red, next is white/orange, then white/green, and last is white/tan.

little background: last issue was crankshaft pulley disconnected from crank hub. Pulley went way back toward block. Visual inspection did not show any affect on Crankshaft Position Sensor. Misfire started earlier this year when I was on interstate. Started sputtering, then MIL started flashing code for Cylinder #3 misfire and multiple misfire. slowed down and it went to normal until I pulled a hill. replaced fuel filter. worked great around town, then when back when pulling on interstate same condition returned. I replaced the coil pack. Worked fine for a while, then started random missing with no code. So I replaced the plugs and plug wires. Now, last check was a cylinder 3 misfire.

I will check for current codes and get back to you. It does have a bad miss which I was trying to find. However, I connected to wrong wire to coil pack.

Thanks.

Yes, check for any codes.

As far as the miss, do a compression test to be sure there is no internal engine issues.

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

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

Roy

Spark intervals are not consistent and therefore causes the car to misfire as if not on timing or wrong firing order. We can't even find obd plug.

Data link is below dash on left hand side, get codes and re post for further assistance.

Good evening! Thanks for response to my previous request. We found the Data link and therefore tried to do diagnostics. Unfortunately the system we used couldn't give us option for this Ford Ranger model. And the system we've been using is " Auto Boss V30 SPX. Please advise me further in this regard.

You will have to find a quality scanner as I will require the set codes to work out the problem you are having

Good day Sir, the only data that reflects repeatedly is P1000

In neutral or park, engine starts missing @ 3000 rpm. Will not run above that rpm. Take truck on road and it performs perfect; no miss, no hesitation, accelerates right through to 5500 rpm.

Hello –

To better assist you can you tell me your engine size in liter and the 8th digit of your VIN.

Also, please go to Auto Zone (AZ) or O’Reilly’s (OR) and for FREE they can pull the codes to the car. Most important: Once they check your codes, if they find something and you don’t get it fixed and need to get back with us, please make sure you tell us exactly what the code was, number and all. Example, if the code was E0568 O2 Sensor bad. Then make sure you give us all of that. While there for FREE also they can bring their tester out and check your battery and alternator.

This code is set after an ECU re flash, you may just need to do a drive cycle to do the re learn first.

It is a 3.0 litre and the 8th digit of the vin is the letter U. Also, is it possible there is a rev limiter for when the truck is not in gear?

Good day! Thanks for previous response. I'm not very sure if by drive cycle you mean I should drive around, but the car doesn't start. It sound like releasing a low spark.

Hello –

Thanks for getting back with me.

Did you have time today to perform the checks for codes, battery etc?

In your original question you said it was misfiring, now you say I does not start, what is it doing exactly, I need correct info to try and help.

I did have the battery and altenator checked and they were both functioning prorerly. The check engine light did not come on and there were no codes.

The car was first misfiring on two plugs and smoking, I overhauled the engine and put new set of plugs. I timed it with cam position one v-up and four v-down, when my crank mark on zero, On starting the car I had to move plug wires around for it to start, even though it was still misfiring. It was blasting when on their real position. So it idled for six to seven minutes and it just stopped running. After that it never started again..

Hello –

Thanks for the info

Okay, so if I understand you correctly you had the battery and alternator checked and both are good.

The light does not have to be on to have thrown a code. So you check the codes with a scanner though and no codes were thrown.

Is this when the engine is still cold, say the first start of the day or does it do it all the time even when the car is warmed up?

At 60,000 miles, you are supposed to replace: Air cleaner filter, fuel filter, spark plugs and a few other things, but those don’t relate to your condition.

First, take a spray bottle of water and start the engine and mist the water all over the plug wires and see if it anything changes. Let me know.

Some of the things that can cause a rough idle are the throttle position sensor, mass air flow sensor, a vacuum leak, the EGR valve.

My suggestion is to do the normal required maintenance above to include the wires. Look at each plug though to see how it looks and let me know.

Then answer the above it there is no change. Your thoughts?

Have you checked injection pulse, compressions and fuel presure

replace. spark plugs, spark plug cables, catalisti converble,mufflerand pipes. all sensor,fuel injectors,troter, all the parts out side the engine was replase. compretion on each cylinderis about 90 bls. across.

[quote:e63a4d91cc="rmt2323"]Engine Performance problem
2004 Ford Ranger 6 cyl Two Wheel Drive Automatic 60000 miles

In neutral or park, engine starts missing @ 3000 rpm. Will not run above that rpm. Take truck on road and it performs perfect; no miss, no hesitation, accelerates right through to 5500 rpm.[/quote:e63a4d91cc]

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Sorry I am here because of PM was sent to me
and this is what I think

It is very normal for the PCM to limit the RPM when no load reading
when RPM reach 3000 or above PCM looks for load
and since its in neutral or in park (load is very low if any )
PCM will shut down injectors to limit the RPM and protect the engine from internal damage
so I believe what you are experiencing is a normal operation
if it running and driving fine and no check engine light on
I would say all good and nothing to worry about
do you regular maintenance
and happy driving

2004 Ford Ranger engine light comes on( randon miss fire ) P0300 normally points to vacuum leaks and bad fuel

Could be caused by the following worn or fouled spark plugs, a weak spark (weak coil, bad spark plug wire), loss of compression, vacuum leaks, anything that causes an unusually lean fuel mixture (lean misfire), an EGR valve that is stuck open, dirty fuel injectors, low fuel pressure, or even bad fuel.

Good day. I've changed my cam positions of one and four respectively, i.e, changed my timing from one to four. The engine is now excellent and very powerful. But firing order has changed completely in all terminals. I'd like to thank you for every effort and time you have offered, with your advises and concerns on making sure that I get the car in good condition. Thanks!!!!!

thank you for the feed back, good tom hear all is well now.

Okay so for the past 2 years, the check engine light in my truck has been sparatically on and off. When it comes on and begins flashing usually when idle. the car idles real rough and when i push the accelerator it takes off extremely slowly, untill about 30 mph and then the engines power returns and its ok and the light stops blinking. Now there are some times it will be on for a month or two and then it'll go away for another 2 months. its very random. When it first happened i had it scanned and it reported a Cylinder 4 misfire. Since then i have replace the fuel filter, cleaned the injector, replaced the spark plugs, replaced the wires and was told that my O2 sensor was ok and there was no vacuum leak. No one can give me a straight answer to fix the problem and i cant afford to take it to a dealership for 3 days only to find out i could fix myself and save 600 bucks. please help me.

Sounds like an injector that is intermittently shorting out.When the light is on, or it is missing, you need to use a meter to measure the resistance across the injector and compare it with another one or to to see if it iis different.Ther are unfortunatly no "straight" answers when dealing with intermittent issues, unless you are able to do some testing during the failure.I would have it scanned again just to be sure it is coming up with the same misfire.

I'm having the same exact issue. I took it to a shop and explained the problem. They replaced an injector. I drove it out of the lot and the problem started at the first light I stopped at.

I'm stuck with this one as well.

KEEP GETTING CYLINDER 6 MISFIRE. INSTALLED NEW PLUGS, WIRES, INJECTOR, CRANK SENSOR,COIL, AND CHECKED COMPRESSION. STILL HAS MISFIRE. WHAT DO I DO NOW?

Have you checked compression, fuel pump pressure, and the injector to make sure it is getting power?

I CHECKED COMPRESSION, HAS 150LBS. USED NOID LIGHT.GOOD PULSE. HAVNT CHECKED FUEL PRESSURE. DIDNT THINK FUEL PRESSURE WOULD CAUSE A CYLINDER TO MISFIRE. IM LOST!!!

It can. If you have a good pulse at the injector and compression, it is either a short in the plug wire, coil, fuel pressure, weak spark to that cylender, or even a vacuum leak.

I have a 2004 Ford Ranger 3.0 V6 with about 80k miles on it. A few years ago, while I was idling, the check engine light started flashing and it started running rough. The RPMs lowered to about 800 and the needle was bouncing a bit. Ten seconds later it picked right back up.

This would happen sporadically but it became more and more constant until it would do this anytime I stopped the truck and idled. However, whenever I started driving the power would kick right back in. The problem only happened when I idled.

The check engine light eventually stayed on. I used a code reader and it had two--that the truck was misfiring under 1000 RPMs and that the #6 cylinder was misfiring.

I took it to a shop and they diagnosed it as a bad plug (their code said it was the #4 cylinder). I paid them to replace the plug, drove off the lot and at the first stop the truck started running rough again.

The shop wants to tear down the engine and I'm not able to have it registered until it passes smog--which it won't because the check engine light is on. Any ideas? I've changed plugs and wires and I've cleaned the air sensors.

code for #4 is p0304 for six its p0306 compression test will tell if engine work is needed or if you have a bad injector or coil. try moving the coil to a different cylender if problem movrs with it replace coil.

The compression test came up normal. I'll try moving the coil. Thanks!

Fixed?

Not sure... The coil pack for the 04 Ranger isn't the kind that you can move the coils around (I was told you could with older versions). I couldn't get a shop around here to bench test it so I swapped it out with one that I know works properly. Because the truck's not currently registered I've only let it idle and the CEL hasn't triggered yet. I'm hoping to put some miles on it soon to see if that was the issue. I'll add an update once I'm confident either way.