Hello all!

I have a 2000 Ranger 2.5L that has developed a rough idle. I went to autozone to have them hook up their code scanner and it doesn't do anything when they hook it up. I have cheap one at home that does the same thing. Acts like it isn't even plugged in- nothing.

I've been reading about the possible rough idle solutions and have so far replaced the plugs and wires (which needed done anyway) and the PCV valve, but any thoughts on why the scanners can't read anything?

As I sit here thinking about it, maybe it's a bad fuse. The cigarette lighter has been dead forever, and if they're connected that's probably it. I guess I'll check it out over lunchtime.

Yep, there was a bad fuse.

The code scanner returned P0302, which looks like a misfire on cylinder 2. Could it be a bad coil?

2 days ago i got code p0303, misfire cyl 3. I added a bottle of techron and changed my fuel filter. the code is gone and truck is running a lot better. I still am investigating a slight hesitation.. your misfire can be from spark, fuel, etc. have you done any recent maintenance.

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2004 Ext Cab, 4WD, 4.0, Auto, 154k. (4.0 engine is out of a 2009 Ranger w/96k) ( as of 7/1/2017)

2004 Ranger, Ext Cab, 2WD, 3.0, 5 speed , 4WABS, crank windows, no cruise, Edge 116k.(6/5,2014) (SOLD).
1999 Ford Ranger, Reg Cab, 2.5, 5 speed, 2WD, no AC, 150k (SOLD).

No maintenance done recently other than new plugs and wires and a pcv valve which apparently did not fix the problem. I did run about 1/2 a can of Seafoam through the gas tank with no improvement just prior to the plug and wire change. Haven't tried running Seafoam through the brake booster yet.

I will try a new fuel filter and cleaning the MAF sensor this weekend. I was also thinking of switching the coils around to see if that helps, since I have heard the passenger side plugs are not really as important as the driver side ones.

Thanks for the suggestions.

you might as well clean the maf. it is good to do. I dont think that is the issue. you will need a torx 20 tamperproof. the fuel filters require a special removal tool. you need the 5/16 one. the kits are about $10. I think the the passenger side cleans up the combustion waste.

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2004 Ext Cab, 4WD, 4.0, Auto, 154k. (4.0 engine is out of a 2009 Ranger w/96k) ( as of 7/1/2017)

2004 Ranger, Ext Cab, 2WD, 3.0, 5 speed , 4WABS, crank windows, no cruise, Edge 116k.(6/5,2014) (SOLD).
1999 Ford Ranger, Reg Cab, 2.5, 5 speed, 2WD, no AC, 150k (SOLD).

Alright, I will be sure to get the kit and t-20 screwdriver. With some luck and hopefully less frustration than was involved with changing the spark plugs and wires, my Ranger's problems will be solved soon!

Thanks again!

tamperproof torx 20

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2004 Ext Cab, 4WD, 4.0, Auto, 154k. (4.0 engine is out of a 2009 Ranger w/96k) ( as of 7/1/2017)

2004 Ranger, Ext Cab, 2WD, 3.0, 5 speed , 4WABS, crank windows, no cruise, Edge 116k.(6/5,2014) (SOLD).
1999 Ford Ranger, Reg Cab, 2.5, 5 speed, 2WD, no AC, 150k (SOLD).

Well I did everything including swap the fuel filter. I am having a problem with a leaky connection on one of the input connections to the filter though. It seems awfully loose compared to the original one and I'm not sure if I am getting it on there good before inserting the clip.

The other connections seem ok though.

I have never run into an issue where the filter leaked. did you see the seal in the fuel line? did you push the line all the way in. I usually hit them with liquid wrench the day before i am going to change them. I think they sell a repair kit for it. you might even want to call the stealership.

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2004 Ext Cab, 4WD, 4.0, Auto, 154k. (4.0 engine is out of a 2009 Ranger w/96k) ( as of 7/1/2017)

2004 Ranger, Ext Cab, 2WD, 3.0, 5 speed , 4WABS, crank windows, no cruise, Edge 116k.(6/5,2014) (SOLD).
1999 Ford Ranger, Reg Cab, 2.5, 5 speed, 2WD, no AC, 150k (SOLD).

I must not have gotten it on all the way the first time, but I finally got it on with no leaking. It runs better for sure, but it still idles rough a times. The more miles I drive it, the better it performs.

I'll just keep driving it and try to figure it out.

Great was the filter clogged. Did you blow thru the new one and old to compare. Put injector cleaner in the tank. Do a fuel pressure test if you can. Harbor freight sells a tester for $20

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2004 Ext Cab, 4WD, 4.0, Auto, 154k. (4.0 engine is out of a 2009 Ranger w/96k) ( as of 7/1/2017)

2004 Ranger, Ext Cab, 2WD, 3.0, 5 speed , 4WABS, crank windows, no cruise, Edge 116k.(6/5,2014) (SOLD).
1999 Ford Ranger, Reg Cab, 2.5, 5 speed, 2WD, no AC, 150k (SOLD).

Well, I didn't compare the flow rates, but I know it needed changed. Dark colored fuel came out of it when I tipped it upside down. I have almost 200,000 miles on the Ranger and I've never changed it before.

I will try some injector cleaner in the tank next and will look into a fuel pressure tester. I assume the tester screws onto a valve on the fuel rail?

there is a shrader( looks like a valve on a tire) valve on the fuel rail. hook the tester onto there. do a koeo test looking for around 65( you might have to cycle the key on and off a few times) and then do a koer test looking for around 65. I had the same issue with my truck p0303 1 week ago. I changed the filter added a bunch of injector cleaner and drove it. seems to be all better and my koeo pressure is 62 with one cycle before it was 7 cycles to get to 62

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2004 Ext Cab, 4WD, 4.0, Auto, 154k. (4.0 engine is out of a 2009 Ranger w/96k) ( as of 7/1/2017)

2004 Ranger, Ext Cab, 2WD, 3.0, 5 speed , 4WABS, crank windows, no cruise, Edge 116k.(6/5,2014) (SOLD).
1999 Ford Ranger, Reg Cab, 2.5, 5 speed, 2WD, no AC, 150k (SOLD).

If all that doesn't work, you may have a bad vaccuum line. That can sometimes cause a rough idle as well.

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'00 Ranger 2WD
2.5L Inline 4
31x10.5 Tires
Flowmaster muffler w/ turn down
Airflow module