My Ford Ranger 3.0L FFV 2X4 recently developed an odd characteristic where it will stumble at steady state speeds. For example, it is most noticable at 25-30 miles per hour while tacking around 1800-2000 rpm. My truck has 57,000 miles on it.

It doesn't do it for the first 60 seconds of driving (while completely cold) but once the engine begins to warm up it starts to stumble. It doesn't seem to do it when the engine it completely warm or at least isn't bad enough for it to be an issue. Another interesting point is that if I accelerate is doesn't misfire and idle seems to be fairly smooth although I do catch a little "blip" in the idle here and there but I wouldn't call it a miss by any means.

I drove it this way for a few weeks and then it threw a CEL. We pulled the codes and it gave us P1151 and P1131 both of which indicate a problem with the upstream O2 sensor. Hence, I replaced the upstream O2 sensor which seemed to clear up the problem until I realized that I warmed the vehicle as recommended in the manual to make removing the sensor easier, so of course it wouldn't do it.

Since replacing the O2 sensor I haven't had the CEL come on but my problem is still there. Just as regular maintainence I replaced the fuel filter about 7,000 miles ago, have new plugs, air filter, cleaned the throttle body and cleaned the MAF sensor. The only thing I haven't done is to change the plug wires (but they don't spark in a dark garage). I should also mention that I have run multiple cans of fuel injector cleaner though it, tried different levels of octane gas and tired different gas stations. I also looked over all the vacuum hoses and everything appears to be O.K.

I'm not sure of what to do next. Any ideas? Any help would be much appreciated as I am baffled. Perhaps a fuel problem? I should also mention that I only drive this truck about 7-10,000 miles per year as I use it for weekend work around the home and as a commuter in which I only live about 2 miles from home (so this is when I drive my truck--when it is in the warm-up period and stumbles through town).

Thanks in advance for any imput.

John

 

You were running lean. The 1131 and 1151 codes indicate that. Since you said you checked for air and vacuum leaks already, my first impression is to agree with your hunch that the cause is related to fuel dilevery.. So you should consider the following

- Leaking fuel pressure regulator
- Low fuel pressure
- Bad fuel injectors

Also, make sure your PCV system is secure, and keep in mind that a faulty EGR system can also lead to a lean condition.

 

Thanks Rockledge! You have pointed me in a good direction. I'll check over the fuel system, PCV system and EGR system. I'm wondering if perhaps it wouldn't hurt to change the DPFE sensor? I'll also check the EGR valve for proper function.

 

Good news! I have solved the missing problem thanks to your imput. I first tried replacing the PCV Valve because it was cheap--no change. I then changed the DPFE sensor and the DPFE sensor hoses--it all only cost about $75 including the hoses. My truck has not hesitated or stumbled since. Thanks for all your help. I must have been getting a little too much air through the ERG system. The DPFE only takes about 10 minutes to change too.

 

Good to hear you fixed the problem. It could be that the DPFE was sending the wrong signal to the PCM, causing the EGR valve to open and allow exhaust gas into the combustion chambers at the wrong time(s).

 

K...I'm having the same problem as you...arround 45 or 75 km/hr my 2008 ford ranger 4.0 L SOHC makes a slight stutter and then keeps driving perfectly. It only happenes periodically (sometimes 5 or 6 times on a half hr drive) and mostly when engine is warm. It happed at 120 km/hr once as well...Could this be the same problem? Its very random b/c it wont happen for a couple days and then it just starts again. Any ideas?

 

I have the same problem with my 2008 Ford Escape 3.0 L and i think that i may have the same issues as you did. Will follow the same procedure as you did. Thanks for the help.

 

I put a bottle of that gas line and injector cleaner you can get from canadian tire or wherever and the truck never stuttered again...Its been 7 months and nothen again...I ran my tank to empty a lot so i assum i just had dirt in the filer/lines/injectors, wherever...but she cleaned er out.

 

Thanks Lambert....Off to Crappy Tire to get me some of that stuff. Hopefully the one here in Langley can help.

 

I have the 2004 5.4 and I have the same issue.

odd though, had my knock sensors replaced under my manifold and right after that (like first drive after) this problem started. I suspect its a leak in the manifold gasket as a result of a poor repair.

my question is would i hear the engine sucking for air if thats what it was, because i believe i can here that under load.

thanks!

 

think I have a similar problem my 2008 2.3l 5 speed started jumping last night. also it only does it when I press down on the gas, mostly in 4th an 5 th cause I shift soon. trying to make this truck last any help would be nice. thanks

 

I have a 91 ranger with a 3.0L that does stutter/stumble. Don't have an egr or the dpfe sensor. Ran some sea foam thru it but didn't help. What do u guys think.

 

My 2009 Ford Escape is giving me some cause for concern. The engine will not run steady but stumbles every now and then. When in idle, it goes off. When it restarts, it goes off again within 15 seconds.
Scan returned the following codes: P0104, P0420, P0430, P0456. It seems my mechanic does not really know what to do.
What do I do? Can anybody help?

Nsiekere