Hi Everybody, I'm new to the forums. My name is Eric from Iowa and have a 2003 Ford Ranger - basic of the basic - 2.3L, 5-Spd Manual with ~74k miles.

I got it a few months back and it ran/runs great overall. The only slight concern was that in Jan/Feb (colder months), if I didn't let the Ranger warm up all the way, it would cut-off/jerk when taking off slowly in 1st gear. This didn't seem right, but ran great once it warmed up.

Last weekend I decide to give it a tuneup, so I replace the following:
Spark Plugs - Replaced with NGK Iridiums - old plugs looked a bit old
Spark Plug Wires - put in Premium Autolite Wires
Air Filter - BOSCH Brand
Oil/Filter - Valvoline Synpower Full Synthetic 5W-20, Motorcraft Filter

Fired it up, sounded great. Take it for a spin and at low RPMS, around 1200-2000, it would cut out for a split second, then when I reach 2k or so, it runs like a champ. It's fully driveable, but just doesn't seem right. It happens in a variety of gears, so I don't think trans related.

I did a bit of googling and found that the Mass Airflow Sensor is very touchy, so when changing the Air Filter, it's recommended to also clean the MAS with special spray. I pull the sensor and soak it pretty well (followed the instructions, the liquid evaporates). Give it a good while to dry, put the sensor back in, and it acts just the same.

I'm here to ask, any ideas on the culprit? Perhaps I need to ditch the Iridiums?

Thanks in advance!

 

Welcome and have you checked and cleaned the throtle body ?

 

I haven't, but have googled it and seems quite simple. I might need to make a trip to grab some cleaner, but should be able to check this today.

Thanks for the suggestion and welcoming :). I'll let you know soon...

 

Update: Cleaned the Throttle Body pretty well with special TB cleaner, toothbrush and Shop Rags. It wasn't very dirty but I was able to shine it up good including around/behind the flapper.

Took it for a spin, but unfortunately it still hesitates at very low RPM's under medium acceleration. If I granny drive the truck it doesn't hesitate, but at ~1500 RPMs, if I give it some gas it hesitates/jerks for just a sec or two until it hits around 2k.

Also, this may sound like a normal hesitation you would get driving a stick at low RPMs, as if you needed to downshift. This however definitely isn't right and didn't really have this symptom before changing the plugs/wires/air/oil.

Quick example would be dropping to 2nd gear to slowly take a right turn and then medium gas pedal to accelerate. It will hesitate/jerk for a second or two and then nice and smooth from there...

Sorry for the rambling, I get descriptive sometimes. Anyways, if there is possibly anything I could look at, I'm happily open to suggestions :). I'd just try a different set of cheap plugs, but it was kind of a PITA pulling out the plug wires the first time (I think were OEM's).

 

Did you look at the screen by the MAS in the air tuck pasage way?? Is it clean and how dirty was the existing air filter???

Check Idle Air Control valve.

ANy check engine light on??

 

If it misses make sure you have all the plug wires push onto the spark plugs.

 

Check your Throttle Position Sensor on the the throttle body.

 

I would put it on a diagnostic code reader it should give you a code of what the problem's is.I don't think this is the problem but it could be in the fuel system?

 

Hey everyone, sorry for the delay, been too busy to work on it until this last Sunday. From talking around, I never checked the gap on these NGK Iridiums. I could have with a metal gapper, but I believe that is a no-no. Anyways, I try to find a clay or non-metal gapper in-town and surprisingly couldn't find one without ordering.

So, I decided to pop in some basic Autolites, in which I gapped to .44. I install 3 of them, easiest install ever, and then the last one was a bit tougher to remove. When I started hand tightening the plug, after about 3 full turns, it gets too tough to do by hand. It felt threaded fine in the start, so I slowly tighten it by socket, but it was considerably tougher to tighten than the others :(.

I put the plug wire on and it will not go down all the way flush as the others. It's on there pretty good so I take it for a spin - actually runs great. On the drive, I ponder the tough plug and think maybe I didnt tighten it all the way - hence the plug not going in flush.

So I get home, pull the wire and the metal piece stays on the plug! Oh man, I broke my brand new spark plug wire - Autolite Premium I believe. I pull the piece off with pliers and tighten the plug a little more. I then piece the wire back together and reinstall - still not flush.

This is where I'm at, the Ranger now drives okay but definitely needs another new set of wires.

Any idea on the tough spark plug and the wire not going flush? This simple tune up has really been a pain...

I think worse scenario, if needed I can get the spark plug hole re-threaded or an insert installed, but could totally be wrong.

Thanks in advance for any advice!

 

When you removed the plug did the compression ring from the original or NGK plug stay on the head???

 

Well thats the weird thing, these ones dont have that little metal ring. None of the Iridiums had it, nor the new Autolites i bought. I even talked to the guy at the auto store regarding that and when we opened the autolites, he said they were "tapered" type and wont have them.

Never heard of that, but he was fairly confident.

Unfortunately I think it's something with the threading. I tried hand tightening a handful of plugs in the same cylinder and all of them got pretty tough after 3 full turns. I'm hoping that by slowly tightening it, I didn't severely damage anything...

 

Buy a thread chaser and run it in the trhreads, when done make sure you blow out the clyinder the best you can of shaving with a air compressor

 

Thanks tempfixit, I'm googling this now and it appears very promising. I'll see what I can figure out and will provide an update this weekend :).

 

That can become a problem. the new plug,'s do not come with a ring they are taperd, just be very careful when you rethread and blow the cylenden out to get any shaving out.

 

I have this exact same truck, engine, tranny and problem. Mine has about 135K on it, mostly highway, and it is doing the exact same thing yours was doing. So changing your plugs and wires fixed your problem? I just did that about a year ago on mine, so I don't think that could be my problem, unless I got something that is defective. Is that the only thing that you did on the trial that fixed the problem? I currently am running a can of Berryman thru my gas tank to see if it will clean out my fueling system. It almost feels like a vacuum leak, since it cuts out only at lower RPM's when accelerating rapidly. Just like yours, mine does not cut out when I baby it, and it runs much better once warmed up good.

 

The fourth spark plug wire hole is slightly smaller than the other four. I don't remember the wires I bought but for the life of me I couldn't get that fourth wire to seat on the plug. Then realized the fourth hole was smaller but all my plug wires had the same size seat. Could be you have the same issue. I also had this same miss/hesitation problem you mentioned after installing NGK irduim plugs. Pulled the plugs and none were gapped right, all had to large of a gap. Mine were from .003 to .007 too large of a gap. So I regapped the plugs and reinstalled the old fourth wire and that solved my problem. Maybe a no-no but if they are not right you have no choice but to regap.

 

This seems to be a very common complaint on the 2.3s low speed off idle stumble or hesitation.
My 2001 2.3L Ranger has had a minor one in it for years mostly while running down level ground at 40mph in 4th about 1900-2100 rpms. Over the past couple years it has become more and more pronounced. with it now being pretty bad. It may even be sensitive to outside temps like super cold days it seems better than warmer days but could be my imagination. TPS, Idle contol valve, already cleaned the maf.

 

i wish someone would figure it out already..... mine has been getting worse and worse, last few weeks have been change this and fix that, even plugged it in to a coder but it kept giving me IAC and coolant temp sensor codes after i changed them, check engine is never on, but i know light works. checked EGR cleaned throttle body, going to test the TPS soon. cleaned fuel tank and new pump because i was getting <20PSI when keyed up. after i changed pump & filter it ran OK, a little hesitant of the line but much more power than before when it wouldnt pull itself. drove it for 2 days, then all of a sudden it wudnt start, and a day later i get it started but has no power to move itself nor will it run when i press the accelerator. im going searching for possible fixes

 

I did FINALLY get my truck totally and completely fixed. I had been dealing with low rpm stumble and hesitation for years which turned to bucking and missing under load. After new plugs and wires it was remarkably improved but not fixed. Our mechanic here at work told me about the plug wires being culprit. After reading much on the web about this engine and truck AND my smog guy who used to work at Ford told me to change out the coil pack, so I did. I bought one on line as OEM replacement for literally $29 bucks, it was EXACTLY like the one on my truck in every detail. bolted it on the afternoon it showed up and BINGO! problem TOTALLY GONE!....... Truck now runs perfectly at every rpm and gas mileage has improved. Guy at smog shop said the ranger and explorer both had crap coil packs and notorious for going bad making the thing run like crap.....yup!.

 

I tried to fix the bucking under load today by changing to Autolite plugs and Napa Premium 7mm plug wires - and it got WORSE!!!! LOL

Gonna try the coil next....

 

Put a new NAPA coil on it yesterday and it is totally cured. Drives smoother than it ever has.

 

I've been having problems with my 2002 Ford Ranger (120K miles) 2.3 L engine misfiring at certain speeds, most noticeably around 1500-2000 RPM. I thought it perhaps was spark plugs so I replaced them with a set of Bosch platinum plugs. The plugs needed to be replaced since I could not remember if they had been replaced within the last 50,000 miles. It seemed to run a bit better, but soon it was apparent that that was not the solution.

Next easiest thing that might have been an issue was a clogged fuel filter, so I changed that. No change.

Nothing showed up on the diagnostic test codes. I got a message from the tester that the cylnider head temperature sensor was broken or reading out of range. But then I realized I had tested it first thing in the morning, the engine was cold and a quick warmup run (with a mis-firing engine) took care of that problem.

A couple of cans of gas treatment to "clean the fuel injectors" also did not seem to make any difference.

The problem continued to worsen over time to the point where it had a distinct lack of power Note: some would say a Ford Ranger with a 2.3 L 4-banger ALWAYS has a lack of power, but this lacked even that.

So this morning I surveyed the various forums and this seems to be a general problem with the species. Some mentioned changing the coil pack, others seemed to indicate this did not fix the problem.

I pulled the coil and checked the resistance across the secondaries. Both the 1-4 and 2-3 secondary coils bothed checkout around 11.4 kOhms. The primary coils, though both seemed to run around 0.7 ohms, but I noticed if I pressed on the left-most terminal the resistance would vary up to ten ohms or more.

I changed the coil and it seems to fix the problem. There's still a little bit of hesitation under certain conditions, but nothing like before. It runs much, much smoother. I consider the problem fixed for now.

 

I have a friend who works for Ford and i enlisted his help on trying to find why my 02 ranger was bucking and stuttering while picking up speed, usually at lower rpm's while changing gears. The code that came back, or the diagnoses his 5000$ scanner gave was, intake valve sticking open or sticking shut. That's exactly how the scanner worded it. I'm in the process now of trying to get the carbon cleaned away from the intake valve which causes it to stick. It all made sense when all the evidence was gathered. Check with your mechanic about your intake valve.

 

I posted on the runner control valve which after reading everyone's posts on how they were dealing with the stutter at lower rpm's in the Ford ranger I took it to a local garage where a buddy of mine works who was employed at Ford for over 10 yrs. But he believed it was the runner control valve which is located on the driver side of the engine at the bottom, it has two vacuum hoses and an electrical plug hooked into it. After buying a new one it was installed and seemed to do alot right at first but within a few miles it was right back, if I drive hard and fast it really doesn't stutter and buck but at lower Rpm's it's terrible! I replaced my coil pack and it had no impact at all! My map sensor appeared clean. I'm starting to get really frustrated, I'm sorry for the post claiming to have found the issue. I should have waited until it was confirmed. Hopefully myself or someone will find the issue and help others by posting it.

 

I have a 2003 2.3L that is doing the same thing. I had a sudden miss that started instantly about 30k miles ago. I replaced the plugs and wires and it fixed it. About 10k later the coil pack started having problems and it was a bad miss at all RPMS and I couldn't even get above 10mph. Then about 5k miles ago I started having a mild miss/hesitation when accelerating in taller gears when going up hill. At the advice of a friend, I replaced the plugs wires (which only had 25k-30k miles on them) and that fixed the problem. Now I have this low RPM hesitation/miss. I notice it mostly in 2nd gear when accelerating and below 2300 RPMS. It struggles to gain RPMs but the second it hits 2300 RPMS it goes completely away and is normal. After it warms up it doesn't do it either. It will do it in 3rd gear too, but I am rarely below 2300 in 3rd gear.

I am going to hook it up to the computer and check some of the sensors and then I will clean the MAF. But With the plugs, wires, coil and IAC relativley new, I kind of hate to start replacing that stuff again. But I have had problems with repeated failures (IAC failed twice close together and plug wires went bad after just about 25k miles). The coil back was from autozone, so maybe I should get an OEM one. I will check the resistance of the unit first.