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Discussion Starter #1
I have a 02 SVT, that just hit 77k. About 10,000 miles ago i was getting some crazy hesitation and jerking around 2800-3200rpm (at any speed, and didn't seem to occur worse or better at any particular speed ban) I replaced everything i could afford in the way of fuel and spark (plugs and wires, altentor, ignition coil, and fuel filter)--same problem. so after visiting some forums i discovered a common problem with the MAF that could be fixed with a computer update at the dealer..dealer flashed it and tada! no more problem! well about 500 miles ago, the problem seems to be returning. this time the jerks are not nearly as noticable, or consistent (before it would ALWAYS do it) it also seems to happen at a slightly lower range of rpms (2600-3000k) so really i'm not sure if it is the same problem; I love this car and hate to give up on it--it's the first car i have ever bought myself and i own it!--but i cannot afford to pay $100 at the dealer every 8-10k miles; or to keep playing trial and error with the replacment parts...i have again! replaced the plugs and wires and fuel filter...no better.

does anyone have any idea what this could be? if it is the computer again, should the dealer have to flash it again for free since it's been such a short time? will it continue to reoccur? please help--the dealer has been no help, they "can't find anything wrong"
 

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The fact the reflash fixed it temporarily suggests a bad sensor possibly. I.E. The ECU has a function called "adaptive learning", so essentially, it's relearning bad things. You may want to try this. Remove your negative battery cable for 5 minutes. This will zero your adaptive tables in your ECU and it will take it a while to relearn them. During that time if it runs good, then I would bet you have a bad sensor. But 1st thing is to see if that helps of not.
 

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Well, first off, you can reset the ECU yourself. Here's how to do it: first warm the car up to normal operating temps, then remove the negative terminal from the battery for 10 mins or more. Afterwards, reconnect the neg terminal, and start the car. Allow the engine to idle for 5-6 minutes without touching the accel. This will reset the air/fuel ratio. The ECU times 5 minutes of idle to reset the A/F. If you watch the tach during the reset, you'll notice it fluctuates slightly, and once the A/F is reset, it drops slightly.

As a guess, I'd say you have TPS issues, but at this point it's hard to tell. It could be something else, so I'd have to agree with the Ford techs that you should wait until the problem is bad enough to be diagnosed properly. There are some things that you can clean and check on your own.

1) The wires leading to the coil pack. The plug-in to the coil pack has caused problems similar to what you're having. The problems are usually a loose wire, so pull on the wires and see if anything is loose. If so, you can get a "pigtail" from your Ford dealer to repair the problem.
2) Check the alternator output. The easiest way to do this is to use a voltage tester between the two battery terminals with the engine idling. Correct voltage should be more than 12v and less than 14.5v. Ideally, it should be on the high side around 13.9v. You can use the TB under the hood to rev the engine to approximately the RPM where you have the problem and see if something happens with the voltage. It might be best to have some help to do this unless you have 3 hands or are clever.
3) Clean your TB. Use a rag with carb cleaner on it, and just clean what you can reach. You can also use your hand to move the throttle plate and clean what you can on the back side of the plate.
4) Clean your MAF. This is probably the MOST important of all the things I listed. The cheapest way is to remove the MAF, and use alcohol on a Q-tip to clean the little resistors in the front side of the MAF. Check our Complete HOW-TO Archive Archive for more information on how to clean the MAF.
 

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dont give up on your car... you just landed on "Focus Haven"... you will get your answers in here.... for now just do what whynotthinkwhynot and soconfused said...


and welcome to FF
 

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Oh! the MAF. Oh well, thats a sensor! 8-D. You don't by chance have a aftermarket airfilter like a K&N that has been recently re-oiled? MAF pollution is pretty common.
 

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Take the effort and try to find a local shop that has had the same mechanics for a long time. The dealership, if it's like the ones where I live, rotate through people like you wouldn't believe. My brother in law works at a small shop and the dealerships occasionally send the seriously weird problems to the smaller shops simply because they would rather rotate tires, change oil and replace tire air with nitrogen than solve a tricky problem.

Also, if you "give up" on your car, you'll be trading a vehicle with a driveability problem which will lower your trade value. Even $100 every 8,000-10,000 is a lot less than $300/mo for a Chevy Aveo.
 

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Discussion Starter #7
thanks a lot

thanks for all the responses, i'm going to try everything! i'll get back with what solved it! thanks again!
 

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Discussion Starter #8
no k&n but it has a low-end cold air intake on it--that came on it when i bought it....so good call on the air filter
 

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the dealerships occasionally send the seriously weird problems to the smaller shops simply because they would rather rotate tires, change oil and replace tire air with nitrogen than solve a tricky problem.
Been at my dealership for 5 years and never not once have we done that. Its always the other way around...except the smaller shops want us telling them what wire is what, where the wires are, what they go to, what color they are, how to do it, blah blah blah and at that, for free.

But yeah, undo the battery and lets see what happens.
 

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Discussion Starter #11
Well, first off, you can reset the ECU yourself. Here's how to do it: first warm the car up to normal operating temps, then remove the negative terminal from the battery for 10 mins or more. Afterwards, reconnect the neg terminal, and start the car. Allow the engine to idle for 5-6 minutes without touching the accel. This will reset the air/fuel ratio. The ECU times 5 minutes of idle to reset the A/F. If you watch the tach during the reset, you'll notice it fluctuates slightly, and once the A/F is reset, it drops slightly.

As a guess, I'd say you have TPS issues, but at this point it's hard to tell. It could be something else, so I'd have to agree with the Ford techs that you should wait until the problem is bad enough to be diagnosed properly. There are some things that you can clean and check on your own.

1) The wires leading to the coil pack. The plug-in to the coil pack has caused problems similar to what you're having. The problems are usually a loose wire, so pull on the wires and see if anything is loose. If so, you can get a "pigtail" from your Ford dealer to repair the problem.
2) Check the alternator output. The easiest way to do this is to use a voltage tester between the two battery terminals with the engine idling. Correct voltage should be more than 12v and less than 14.5v. Ideally, it should be on the high side around 13.9v. You can use the TB under the hood to rev the engine to approximately the RPM where you have the problem and see if something happens with the voltage. It might be best to have some help to do this unless you have 3 hands or are clever.
3) Clean your TB. Use a rag with carb cleaner on it, and just clean what you can reach. You can also use your hand to move the throttle plate and clean what you can on the back side of the plate.
4) Clean your MAF. This is probably the MOST important of all the things I listed. The cheapest way is to remove the MAF, and use alcohol on a Q-tip to clean the little resistors in the front side of the MAF. Check our Complete HOW-TO Archive Archive for more information on how to clean the MAF.


TPS DID IT!!! THANKS EVERYONE!!!!
 

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Glad the TPS was the fix.

I MAY have more good news for you. However, it is going to irritate you.

You need to go back to the dealer and get your money refunded. If they had to reflash the ECU on the car and you have less than 80K on the odometer, that service is covered by

A FEDERALLY BACKED EMISSIONS WARRANTY

http://www.epa.gov/otaq/consumer/warr95fs.txt

Excerpt from the LAW:

EMISSION RELATED PARTS

These are examples of other parts of your vehicle which have a
primary purpose other than emissions control but which nevertheless
have significant effects on your vehicle's emissions.
If any of these
parts fail to function or function improperly, your vehicle's
emissions may exceed federal standards. Therefore, when any of the
parts of the following systems are defective in materials or
workmanship and have failed in a way that would be likely to cause
your vehicle's emissions to exceed federal standards, they should be
repaired or replaced under the emissions warranty:

Fuel Injection System

fuel distributor

Air Induction System

turbocharger intake manifold

Exhaust System

exhaust manifold

Ignition System

distributor spark plugs
ignition wires and coil

Miscellaneous Parts

hoses, gaskets, brackets, clamps, and other accessories used in
the above systems.


What Are Specified Major Emission Control Components?

There are three specified major emission control components,
covered for the first 8 years or 80,000 miles of vehicle use on 1995
and newer vehicles:

* Catalytic converters.

* The electronic emissions control unit or computer (ECU).

* The onboard emissions diagnostic device or computer (OBD).
 

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Be sure to see previous post.

BTW - Welcome to focus Fanatics.[welcome]

Hope you stay a while! [:)]
 
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