2000 Ford Ranger, 2.5L, 225,000 miles, no catalytic converter. I purchased truck with 175,000 miles on it. It ran ok when I got it, but has always seemed low on power and gas mileage.

Now truck runs worse by the week. Won't go over 60 mph floored. Starts and idles ok when cold, less so when warm. Dies constantly at stops. If I press on the accelerator too quickly, it stumbles and dies. I have to keep feet on gas pedal and brake at same time to keep it running. I do not hear any knocking, tapping or other telltale noises from the motor. Sitting in the driveway, when I run RPMs up to around 3,500 it seems to flatten out, like valves are floating? Don't read too much into my description, I'm just trying to explain what I'm hearing. It's basically undriveable and I fear it's going to strand me soon.

I took to it to AutoZone and had codes scanned.
• P0301 / P0302 - cylinder 1 / 2 misfire
• P1401 - Differential Pressure Feedback EGR Circiut High Input

This weekend I performed the following:
• changed spark plugs and spark plug wires, old plugs looked ok
• cleaned MAF sensor with MAF cleaner
• new air filter
• swapped coil packs around to see if any change; none (has spark at all plugs)
• new fuel filter
• limited checked of fuel –simple tire gauge @ rail showed pressure@ 55 psi
• changed oil and filter
• replaced PCV valve
• cleaned out IAC valve
• searched/sprayed for vacuum leaks, but did not measure overall vacuum - no gauge
• checked injector #1 resistance; ok @ 15 Ohms; could hear it pulsing normally
• on 2nd tank with Lucas Oil fuel treatment


Things I didn't do yet:

• did not check resistance of other injectors due to time constraints
• did not check cylinder compression, no gauge yet
• did not check timing, no light
• did not buy new DPFE sensor (yet)
• did not remove EGR valve, for fear of twisting off a bolt or breaking the tube. I need to drive it to school/work almost daily

The things I've done so far needed to be done, so not a waste of time/money. I will try to get codes scanned again to see if anything else pops up. So far I don't think it runs any better. I did not install a new DPFE sensor yet, resisting the temptation to start throwing money at every possible cause and still not fix it. Can the DPFE sensor or EGR valve cause it to run THAT badly?

I've scheduled a diagnostic check next week with a nearby repair shop hoping they can more efficiently diagnose it. I have the tools and ability to do most repairs myself, but I can't afford to be without my truck for more than a couple days because I work and go to school.

Can anyone suggest what else I should check before I take it to the mechanic? Keep in mind I need to minimize downtime (and hopefully expenses), but will do what's necessary to get it fixed.

 

Update:

Just finished checking compression. Engine at operating temperature. Cylinder readings as follows:

1. 10
2. 110
3. 180
4. 170

Repeated with oil added to each cylinder:

1. 20
2. 135
3. 190
4. 180

What I find odd is that engine makes no ticking or knocking noises and actually idles fairly decent when cold. Obviously I'm going to have to pull the head off, but I need to be prepared to do whatever it needs and get it back together. This is my only vehicle and can borrow my parents car for a couple days to a week at maximum. Is a leak-down test necessary? Could it be a simple head gasket? What's my next step?

 

Wow, not much help here, not even one person offered advice, in over a month. I'll update just in case another user can benefit. Pulled head, had blown head gasket and tiny cracks between 2 valves. Salvage head rebuilt and put all back together, now purring like a kitten. Luckily I got lots of good advice in another ranger forum.

 

Yikes, glad it was just the head. I never saw the thread myself, but I don't think I could've contributed too much..

 

i was going to say it sounded like a typical 2.5l which other forum are you on? my ranger has 160k miles on it and it drives worse than my old nova with over 300k miles. mine is a 2.5l as well. it tries to stall in 1st gear, gets worse mpg than anything else ive owned recently, and its a 5 speed...i just started on this forum today, otherwise id have tried to help somewhat.

 

From the sound of it you definitely don't have a "typical" Lima.