I've got an issue on my Escape, and I'm at a dead end. '01 XLT V6 150K miles.
About a week ago, driving to work, it started stuttering or misfiring while accelerating up inclines. Cruising and idle were smooth with no issues. I found that if I let off the gas as it was stuttering, it would stop, and then I'd give it gas again, and it would be fine. It was pretty intermittent.
Opened the hood and the large vacuum hose that goes from the top of the intake down to the PCV, has an L boot that connects it to the intake n****e. That boot was collapsed down on itself while the motor was running. It went back to normal when I shut it down. I felt the boot and it was very thin and wornout, so I replace the whole two piece hose, along with the PCV valve. The old PCV came out and was rattling, so I believe it was ok, but I installed a new one anyway.
Drove it after that and it still had the stutter. It was now also doing it just barely at idle. I'd hear the motor miss, and it would really start when I would give it gas. I thought it was still a vacuum issue, and that there were probably other bad hoses. I found two. There's a small hard plastic line that comes off the air intake hose from a T, and those lines go to the camshaft covers. The hard lines go to rubber boots on the cover, and the one in the back was in two pieces. Replaced it. No change.
The other line is a small rubber line that comes off a round component, (sorry, I still haven't found out exactly what this part is called), that is bolted to the drivers side shock mount, and has a couple soft lines coming off of it. One of the lines goes over the top of the motor and ties into a T right where that large PCV hose goes into the intake. The part is circled in red, and the arrows point to the hose in the attached pic.

 

I was looking around for other damaged hoses, and when I moved that hose I heard and hiss and found a nice gash on the underside of it.
Replaced it. No change.
There is another hose that came off that same part circled above, that goes over just under the air intake on the drivers side of the motor. That wasn't broken, but its pretty crusty, so I'm going to replace it also.
I've not checked the EGR valve yet, but will try that too. I have this posted on another forum, and people are suggesting a bad fuel pump, and/ or dirty filter. The filter was replaced four years ago along with the coils, plugs, and plug boots when I did it myself. I didn't have any engine problems until now. I used an OBD2 reader, and it shows no codes, and the Check Engine light has not come on.
I called a mechanic I know and just over the phone with a quick rundown, he says it sounds like coils. Again, their four years old, and I replaced them with Standard Motor Products, so they weren't the cheap ones.
I've also cleaned the MAF sensor and throttle plate; neither were very dirty. I replaced the air filter. I added fuel injector cleaner and a full tank of gas.

 

With finding the damaged hoses, I had tunnel vision that it was a vacuum problem, but I don't think that's the main issue. My wifes envoy did the same thing recently, and it turned out the plugs were fouled. New plugs and hers was driving fine. Thinking that might be the problem, I pulled one on the Escape's front bank, and it looked good, but again their only four years old.
Any other suggestions on what to check???? I'm going to try to test the EGR valve tomorrow, and also blow some smoke over the motor to see if I do have any other leaks. The mechanic I talked to wouldn't be able to look at it for a week and his suggestion was drive it until it throws a code so it can be read.
Is there anything I could try, or anything that I'm missing?

 

Check into your local Autozone, Advance Auto, ect... and ask to have the codes read. They do it for free. Even if the Check Engine light is not lit, they can read some pre-codes and hopefully point you in a positive direction.

Replacing the bad hoses and fittings is not going to hurt anything, so no effort lost!

My '02 had an issue with misfiring and it was the coils. You want to address it soon so the catalytic converter(s) don't get plugged causing more headache and wallet strain.... Trust me on that.

 

I took it by Oreilly Sunday and used their code reader, and it didn't have any codes showing. It didn't show any misfire codes at all.
I agree on the hoses; I'm frustrated with myself that they got that bad before I noticed them.
I am worried about driving it until it throws a code as the mechanic suggested, because I've read about the problem with the cars clogging after too many misfires. My plan is to drive it and let it misfire as much as possible, and hopefully it'll code. I've been letting off the gas when it does it so it'll stop, but I'll just let it keep going and it'll either throw a code or throw the motor out of the car...

 

I replaced those bad hoses today, and checked the EGR valve, which is working correctly. Drove it about a mile through the neighborhood with various start, stop, and accelerations up a hill. It drove smooth with no issues.
I drove it again about an hour later, and it stumbled as soon as I started it, then off and on while driving. When it would do it, I tried to keep a steady pedal, because if I let off or give it gas the stuttering stops. I wanted it to either misfire enough to give me a code or blowup completely. It didn't do either one. The drive home was smooth as can be...

 

Throttle position sensor maybe?

 

That isn't something I've checked, but I will. A couple sites are showing similar symptoms when that goes bad. It looks like it's checked with an ohm meter, so I'll look into that.

 

I drove it this morning, and was able to find a long stretch of road so I could maintain a constant speed. It started bucking, and after about 15 seconds at that speed, the check engine light started blinking. I stopped at where I was going, and when I started it again, the light was off. I drove it to the auto parts store, and it read no codes again....

So I'm guessing I either have to have a reader with me to use it when the CE light comes on, or I have to go straight to the LAPS and have it read without shutting the motor off?

When I use those readers, they say to have the key on, but the engine off, so how's that going to work?

 

My past experience with my '02 V6 and the CEL being lit is that it needs to read the error for a period of time before it stays lit, then it needs a specific startup/run/shut down routine. Typically, 50 miles of driving around town will fill that need then the light goes out as the system resets or "clears" the error code.
So if the CEL was blinking when you shut down, the code was not retained.

If and when the bucking starts up and your CEL stays on, turn the overdrive off to reduce the bucking and head to a reader. Not using the overdrive increases RPM and it won't buck as bad (past experience). The engine RPM VS Wheel rotation ratio in overdrive is somewhat of a comedy of engineering tolerances. The bucking of the engine is exaggerated through the drive line and your Escape thinks it's a Bronco. Much smoother with OD off regardless of the cause of the bucking.

Just curious... have you noticed a correlation with the bucking and humidity? When my coils went bad I got intermittant bucking like you mention and it was worse with high humidity. Early mornings with a heavy dew or on rainy days was the worst for mine. Once the engine warmed up it was better.

 

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Thanks for the info! I just got back from a 65 mile round trip. When I got close to where I knew an parts store was, I let it buck until the CE light came on steady. P0306. Cylinder 6 misfire. At least it's on the front of the motor, and not the rear bank.

As far as the humidity, I've read about that but have never run into that when it gets humid here. I know when I first bought it, I had a great idea to wash the motor with a pressure washer. After doing so, I tried to drive it, and it was bad... I learned not to do that again!

 

When you remove the coil(s) make sure to mark the wires. I've read that people have managed to route them wrong and they fit! Needless to say you will end up worse than before.
Inspect the coils carefully for cracking around the base of the coil.

Coils can be had for cheap on Amazon, but many here recommend using only OEM equipment if that proves to be your issue.
The rear bank of plugs/coils isn't all that bad if you're moderately inclined to do the work.

 

Yes, I replaced all 6 coils four years ago. The back 3 weren't that bad; and I made sure to mark every connection that I disconnected.

Looking at Rockauto, Denso brand coils are $28 and are marked OEM replacement. Motorcraft are over $70. I used Standard Auto Parts when I did my tune up. It's surprising that Denso, as OEM replacements, are that price.

 

I now it's an old post, but did you have a solution?

 

Better to ask the people here now rather than posts from 3yrs ago.

Start a new thread and post your symptoms.