Minnesota Focus Owners Club

2007 Focus ZX3 S

So... my car's been having some idle issues these last few weeks. I cleaned the MAF, my K&N filter and switched over to Autolite 104's, changed from short ram (winter) intake to my cold air intake w/ stock MAF tube, reset computer multiple times.

Nothing has fixed the problem.
the issue is:
When Rolling to a stop, out of gear. or just stopped all together. when the rev's come down, they drop TOO low (500-ish) and it shakes a bit then jumps up to 800 and settles in the low 700's and then bounces around a bit. never idles smoothly once warmed up. It's been really irritating.

NOW

I just threw a Check Engine Light
I pulled the code.

0171
Mixture too lean
Bank 1 - Closed Loop

I am bringing it to ford tomorrow. I know they're going to hassle me about the intake and exhaust effecting it.
I'll have to fight them to get some answers like always.

But what do you guys think?
I am at 13,100 miles. and I've been running all my mods for over 7,500 miles.

From time to time it starts hard. Like 5+ seconds of cranking... it's irritating.

My next guess... Sticky/Faulty Fuel Injectors
My dad's '06 F150 has had it's injectors replaced twice now because of premature failure.

Share your thoughts, please!

I don't have an answear for you.

But I have had a problem simaler to this. Mine actually died on me, also when accelerating it will cut out like it is on a limiter. My CEL has come on also but when I was going to take it in it turned off, I think the ZX5 heard my thoughts!

I think I have narroed the problem down with my car I *think* it is from Auto Car Washs "the under car wash"

Hope your Question is answeared!

Pat

Thanks for the good will.
My car has never died. it has come CLOSE a couple times (Polly bushings lets me REALLY feel when it's struggling)
But I've never had a single problem with it sputtering during acceleration.

I'd guess a IACV....

IAC or TPS would be my guess.

Also, I believe when the car throws a CEL and the CEL shuts off before you have it read you can still find out what it was because the PCM stores it in memory.

So even though the CEL is gone it should still be able to be taken from memory, I think.

Do you still have the stock intake stuff?

Well, no luck. Ford tried swapping maf sensors and they won't try anything else until I put the stock intake back on. But they are throwing a new throttlebody on to fix the sticky throttle.
Anybody have an unmoddified maf tube I can borrow or buy? Mine is cut off for the intake. Poopy heads won't even test the iac for me

On a good note, I got alot of compliments on the clean modifications. I guess they don't see many good looking foci

I do. I live in brooklyn center.

Well. Cars done
and wow... I can't believe I didnt get the sticky throttle fixed earlier! Its like a whole new car
PLUS
its not idling shifty anymore!
so something worked. We will see how long it lasts

Sweetiles!

Deagle50ae wrote:Well. Cars done
and wow... I can't believe I didnt get the sticky throttle fixed earlier! Its like a whole new car
PLUS
its not idling shifty anymore!
so something worked. We will see how long it lasts

That would lead me to believe it was the TPS, the new throttle body came with one on it.

that could be the case.
I know when I pulled the code it said TPS was at 18% with the car off... not sure why it'd say that.
but come on... 13,000 miles and little stuff like that is already going bad? My '92 olds had 180k on it and the only things replaced was the starter and alternator

Deagle50ae wrote:that could be the case.
I know when I pulled the code it said TPS was at 18% with the car off... not sure why it'd say that.
but come on... 13,000 miles and little stuff like that is already going bad? My '92 olds had 180k on it and the only things replaced was the starter and alternator

It could read that way due to the sticky throttle plate, The TPS needs to return to a known starting point every time or the PCM won't know what the throtlle plate is doing.

If the TPS is stopping in a different place every time the PCM can't read it right.

So once again it may have just been due to the sticky throttle plate and not a failed TPS.