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walker_741 11-08-2012 12:21 PM

Can't figure this out to save my life. Literally.
Ok I am new to the forum and have looked high and low throughout it to try and find an answer but I can't. I would appreciate any help as my next step is to junk the car and by a new one, not ideal since I can't really afford the new Focus I want.

I have a 01 ZX3 Zetec DOHC Automatic and since I bought the car two years ago it has had an idle problem that came and went randomly. If this helps at all when I bought the car the airbags had gone off which made the fuel pump cut off, all I did was hit the button and it reset. The car ran fine while under power and fine while at idle expect once in a while. I scanned the CL on car when I first bought it and it gave me P0171 System lean bank 1. Recently the car has become impossible to drive.

Here is a list of parts I have replaced: MAF, Spark Plugs (twice), Plug Wires, IAC, EGR Valve, EGR Valve Solenoid, Motor Mounts and Fuel Filter. I have also checked every vacuum hose on the car and there are no leaks and the hoses are not collapsing. After replacing all of this the rpms race, it accelerates by itself, and stumbles while I am driving. This makes it hard to stop since the rpms are not dropping as they should.

Now for the weird part of this all. One night as I was driving home I hit my brights and the car stumbled and jerked. I tried it again and the same thing happened. It stumbles pretty much whenever I turn on anything electrical in the car. Now yesterday coming home I went to pass a car and while in the throttle (going 40 mph) the car started to stumble and sputter.

I have begun checking the CPS and am wondering if this could lead to this at all or not. If so I have found that with the ignition on there is no power to the CPS connector and the CPS itself is at 401 Ohms. Could anyone possible tell me if this is correct or not.

I don't want to keep throwing money into it and not have the problem get any better but I would love to have my car back. Maybe I'm just not the mechanic I thought I was or something that I haven't checked is wrong.

drunkyoda 11-08-2012 12:51 PM

check your pcv hose and there is a pigtail on your alternator that is also a common problem. check those and come back.

GreySkorpion 11-08-2012 02:34 PM

Open your hatch up, find the black rubber "boot" that goes from the car to the hatch door and peel back the boot exposing the wires and look for any cracks in the wires insulation. Wrap each cracked wire with electrical tape. It has solved many electrical related problems.

hurtinfocus 11-08-2012 03:20 PM


Originally Posted by GreyScorpion (Post 4446543)
Open your hatch up, find the black rubber "boot" that goes from the car to the hatch door and peel back the boot exposing the wires and look for any cracks in the wires insulation. Wrap each cracked wire with electrical tape. It has solved many electrical related problems.

this is indeed a common issue. But to me it sounds like your throttle position sensor is malfunctioning. it is approximately a $25 part at the local auto parts store.....just pay attention to the way the one on the car is pointing and install the new one exactly the same....if you install it pointing a different direction it will read incorrectly AND damage it.

GreySkorpion 11-08-2012 03:34 PM

I will second the tps and replacement. My suggestion was based on the headlight and surging going hand in hand.

walker_741 11-08-2012 09:57 PM

Ok I replaced the pcv valve and the line. The line I bought is a little pinched but not to bad temporary until I got to ford and buy the right one. The car still stumbles and idles high but not as bad as before. Tomorrow I will go get a new tps and see if that helps. Thanks for the tips

fhh02a 11-08-2012 10:18 PM

Check the coil pack for cracks.
I would , if you can, get the alternator checked while you're at it.
Most auto places can check it.

walker_741 11-08-2012 10:26 PM

Ill check it and see if there are. I looked at it when I replaced the wires it seemed ok but I wasn't looking to hard at it. And I can test the alternator at work (aaa driver) so I will do that also.

whynotthinkwhynot 11-09-2012 05:21 AM

You can use the electronic odometer trick to monitor voltage while you drive. There's no odo test function for amps that I know of though. This can be a handy trick for problem diagnosis. Usually the alternators on these cars are tricky, but don't cause high idle issues. You might also have a TB that someone fiddled with the throttle plate stop screw.
Key off, press and hold odo reset button. Turn key on while holding odo reset. The needles will jump, and the odo will read [test], release odo reset button. Now each time you press and release the odo reset button you will scroll through one of 30 test functions. Look for the one that reads [bat 12.2], and expect it to read about -.2v from what you read on the terminals. The odo will remain in test mode until you turn the key off, so simply start the engine, and now you'll be monitoring alternator voltage while you drive.

The TPS replacement, follow this procedure: remove both screws, but hold TPS in place. It will twist under it's own spring towards the air intake. This is what it should look like when you install the new TPS, then you turn it back to line the screw holes up. Some people make the mistake of installing it with the screw holes lined up, then forcing it with the screws to be flush with the TB face. That's how it gets broken. It happens often enough that I always ask about that when problems show up right after TPS repair.

PO171 is our typical DTC that points to a bad PCV vacuum line that causes high idle. However, other vacuum leaks can cause high idle. Have you checked the intake manifold bolts? Also, some people have missed the IAC gasket, and installed a new IAC with 2 gaskets. Ford is known for not using gaskets on some parts- the IAC is one of them, but typically with aluminum intakes, there is a gasket. If you check those intake manifold bolts- tighten from center to outside.

Forgive me if I'm too rudimentary, we sort of assume nobody knows anything until we know better.

walker_741 11-12-2012 05:00 PM

Ok sorry for the delay. I bought an new tps however it was the wrong one (manual trans one). So I ordered the Motorcraft one and got it yesterday. This one doesn't seem to have a spring to make it return to its original position. Is it supposed to? Maybe I have a defective one because now the car shifts like the sensor isn't working. I can't track down another one to compare it to. With it in though it seems to be driving/idling a lot better besides the rough shifting. I also bought the correct pcv line so that is installed correctly now.

The alternator is working correctly and putting out about 14 volts.

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