Hi guys,


Newbie here. Austin Texas is my hometown. Bought a 2002 Ranger with 45K miles . Good shape.

Engine stumbles when idling about every 3 or 4 seconds. I also got a misfire code on cyl 2 I had autozone check it for me. They cleared the code out. Ive changed out plugs, going to do fuel filter next. Anything else I should check immidiately before I go throwing money at this thing?

 

My 03 is also developing a rough idle. The only code its thrown so far is a misfire, and only once. I replaced plugs/wires/fuel filter before the October Centralia meet. I'm not sure where to go next, without a code my Ford tech buddies are reluctant to offer advice, esp. since they're all adamant that 3.0 Rangers all idle rough.

 

I was thinking abut cleaning the IAC and possibly checking the EGR passage as well. Maybe use some seafoam to do a top end cleaning. Im fairly new to this truck so any advice would be great. Thanks in advance.

 

Is this with the A/C on? Maybe the A/C compressor?

 

have you checked yer o2 sensors?.. they can go bad outa the blue as well, other than that looks like most checks have been brought up. might just need a good cleaning inside after watever happened..

 

I would imagine that an O2 sensor failure would throw a code, but I could be wrong. Mine idles rough with or without the A/C on, I thought the same thing Mike. Its not only rough, but its a little low, sometimes 650-700rpm. Not always though. Also, it usually idles fine cold, but after I run to work (1+hours at 65-85mph on I95) its much more prone to the problem.

 

That's a good thought. I don't know if the O2 sensor can make that happen -- but it's certainly in the loop, so to speak.

Ranger coil packs have been known to have "issues" as well -- however, usually what you have is TWO cylinders that show misfires because each coil fires two cylinders.

All 3.0's DO idle rough -- some rougher than others. I'd tell you to clean your MAF; but you're getting misfire codes for a single cylinder? If you're getting them for two cylinders, and they are the "pair" that goes to a coil pack, you might want to look at the coil pack.

I just replaced my wires, a little after replacing my plugs and my idle DID get smoother, interestingly enough. My wires were 3+ years old, with 60,000 miles and a LOT of offroading water, dirt and mud having hit them.

 

It is most likely the coil pack......2002 locations for the coil pack put it in direct fire....the heat from the manny messes them up....get a new one or a working one and shield it

 

Hey, another Newbie here, but I imagine you already fixed this issue. For others, I thought I would share some knowledge as a red-seal HD mechanic. The 3.0L Vulcan engine is well known for having coil pack issues. The location of the coil pack is right on a hot area of the engine which doesnt help, but the windings internally were not great to begin with. Once they get some miles on them, they start kicking misfire codes on cylinders 1 and 3 if im correct. I would change the coil pack to a replacement motorcraft unit, change the fuel filter, do the plugs and wires and clean the Idle Air Control valve and Mass airflow sensor. . If that doesnt cure it, your DPFE (delta pressure feedback egr) sensor and EGR are likely the culprit.

Hope this helps.