Just got a 2006 Ford Escape for $200, Trying to make it a daily driver for cheap

It was hard to get exact before/after numbers but it seemed to read a bit lower on average. It would still go to 100% with some throttle but seemed like it took a little more then before.

Hmm. So a minute of googling tells me there may be a fuse for the o2 heater circuit. That was on the v6, but the i4 may have that as well. That can be another way to disable/delay closed loop.

Cool, that sounds like the simplest option, I will see if I can find which one that is

Fuse #5. 15amp

Off to give that a try……

Well, sadly pulling that fuse did not keep it from going into closed loop.

I was looking for the temp sensor but could not seem to find it, did some searching and seems it uses a head temp sensor?

I have seen that plug by the coils but was not sure what it was for.

Shoot. Did you at least get DTCs ? P0141

Ok, disconnected the temp sensor in the head and tried again, still went into closed loop.

Although while driving I did notice something odd, when it gets up to the 4k RPM wall it would go into “open loop/deceleration”.

This is the same thing it says when I rev in neutral and the rev limiter kicks in at 4k.

Could it think it is in neutral?

Nope, no codes which I found strange as well, although maybe I didn’t leave it running long enough, I can check for pending codes next time I am out there.

Gonna let it cool off and try disconnecting the O2 sensor tomorrow most likely.

Oh that’s interesting… both getting no code and the idea about neutral/park.

As for the O2, I think I see the connector on the firewall behind cylinder 4 in an image search. Should be another easy one to test. If it goes into closed loop without an AFR sensor, the ecm actually becomes an suspect in my book. As of now, I’m looking elsewhere.

A test maybe for the gear selector might be to try and start it while it’s in drive. If it allows it to fire up, you’re onto something for sure

Another good idea, I will try that now.

Although this might be a more “hard wired” safety vs a ECU decision.

Hang on, let’s take a step back…

Open loop does 2 things: generally runs rich to warm up things in a hurry from a cold start, and (duh) uses open-loop preprogrammed values for everything. Once you go closed-loop, it leans out and uses soft trim-values instead.

So if open-loop is good, more fuel means better acceleration, etc., and those values are programmed at the factory, normal expected values but not trimmed for the specific engine.

Remember the old (rather stoopit) trick of putting a wedge under the accelerator for “better fuel economy”, simply to keep people from stomping hard on the accelerator pedal? Sounds almost like that’s what’s happening closed-loop, ie, something’s tricking the ECM to limit fuel-flow somehow? (Eg, load sensor, etc.?)

I forgot if your engine runs rough or does anything untoward, other than just having a lack of power.

I heard of cases where the VSS or cam/crank sensor, etc., “jumped a cog” and threw off valve timing. Ie, the sensor might read a good timing value, but it’s just off enough to let the engine run, but be horribly weak.

Case in point, miscalibrated temp sensor on Andouille-based lights. My new SC31pro was reading and blinking out 44C-45C, but it was really 23C (then slowly sneaking up to 25C from just sitting in my hand when I was playing with it). So it was thinking the light was already running pretty warm even though it was sitting in rather cool air undisturbed. But!, it was doing exactly what its sw was telling it to do.

So there are a bunch of hits for this model and bad transmission range sensor. This tells the pcm what gear it’s in. Might be something to look into if other things don’t pan out.

In case it comes to that… https://www.amazon.com/dp/B000C7ZR90/ref=cm_sw_r_cp_apa_i_MELCFbXRV5DWX

Ok, tried starting it in drive, no go.

Disconnected the O2 sensor and it was hunting all over the place with the fuel trim and timing for the first few laps of the block but eventually went into “open loop/sys error” mode.

There are also pending codes for the O2, MAF and temp sensor, so guess it was just not long enough for them to become real codes.

While it was hunting there were times it felt better but no pattern I could detect and it never seemed to be up to normal power levels. Once it went into open loop entirely, it oddly seemed very similar to the normal issues I have been having.

At low throttle inputs it would try to die now and at WOT it would also act funny but at normal throttle levels it was not that much different then before. So guess that rules out the open loop being the answer.

It must be the start up tune, if I start it, slam it into gear and floor it, it will take off like it used to for the first few seconds. Then it will fall on it’s face.

As far as any other issues, this is what makes it so strange, it starts, idles and runs perfectly other then having zero power at all. Thats the hardest part, no hints as to where the issue lies.

A timing issue is something I considered early on as well but this is a timing chain engine, is it even possible for it to jump a tooth? There is no rattle from the chain when running, so it would seem to still be tight.

Interesting, at least it is cheap, I need to look through the OBD output again and see if it outputs anything about the gear.

Thanks for all the help and suggestions by the way, I am about to drop kick this thing to craigslist lol.

I know it must be something simple, but no clue what it is. This is easily the strangest issue I have ever had on a car. I have had things I didn’t want to fix or were not worth fixing before but this is the first time I could not even get in the ballpark of what the issue is.

A plugged exhaust takes a few seconds to build up pressure and then cause issues. I would say this would be under 15s for sure and likely around 5-10s. I don’t know if I can rule that out from the descriptions so far…

The fact it runs good for a short time leans me towards exhaust or electronic.

To be clear, if your startup cold, immediately slam into low gear and go WOT, will it exceed 4k rpm?

This is seeming less and less likely. If the trans shifts properly and the dash gear position indicator is accurate, then I would forget about it for now.

I have not actually tried that, I live on a corner so I have to turn after a few feet so don’t generally get above 4k. I can try that tomorrow though when it is cold.

A clogged exhaust is possible, I have not completely ruled it out, sometimes it seems likely, others very unlikely.

I intend to spray the exhaust bolts down with penetrating oil for a few more days at least before I try to loosen anything.

I could pull the muffler off pretty easily since I replaced it, although not sure that would do anything except tick off the neighbors lol.