'02 Ford Focus has severe "sputtering" when cold.

[Acanthus]

I'm relatively new in town and my car has been acting up so I don't have a trustworthy mechanic to take my car to. I'm hoping to get a ballpark estimate of what could be wrong with the car based on the symptoms it is exhibiting.

If you guys can help troubleshoot this it would be a fantastic help.

The car is well taken care of and routine maintenance is done regularly. The only thing i did not do was the 100k mile "tune up" which involves changing plugs & wires etc.

The car "sputters" extremely wildly when it's cold, as in the idle seems to jump around between 600 and 1200 rpms while just idleing park. If i try to drive it in this state it also sputters while in motion, sometimes so severe that i can't get the car up to driving speed.

It has been doing this for a few days but it was finals week so i haven't been able to take the car anywhere to get it looked at yet.

I did some quick research on the symptoms and it appears based on my description that it can be one of three things.

An ignition coil. An oxygen sensor. Or a vacuum seal leak.

The check engine light FINALLY threw last night when i was driving it home from work for a few seconds. Should i take it to autozone and see if they can read an error on the ECU?

Thanks in advance for any advice guys. I'm really hoping not to get bent over on this.

 

[Possessed Freak]

The check engine light FINALLY threw last night when i was driving it home from work for a few seconds. Should i take it to autozone and see if they can read an error on the ECU?

Absolutely. This should clue you in. I doubt temperature has much to do with it, probably coincidence.

 

[Acanthus]

Absolutely. This should clue you in. I doubt temperature has much to do with it, probably coincidence.

The problems definitely subside as soon as the engine is warm. It is really strange to me but I only know enough about cars to do routine upkeep.

 

[LTC8K6]

Idle control valve?

 

[Acanthus]

Idle control valve?

Would that translate to problems at speed though as well?

I am really perplexed because of the problem subsiding when the car has been run for a few minutes.

It will even run fine just from start if the car has been driven in the last few hours.

 

[LTC8K6]

Get the code first and then you'll have an idea of where to "Focus"...

 

[Lotheron]

Definitely get the code, but it could be something as simple as dirty injectors.

 

[Acanthus]

I'll get the code and report back.

 

[alkalinetaupehat]

Could be the plugs/wires on their way out, or a vacuum leak. I have the same problem on my car, except much less severe. The process for leak checking is to get a vacuum testing kit and find out where the vacuum lines are on your car. I purchased a factory service manual on Ebay for $13, and have seen .PDF's going for $3 for some models. These manuals will tell you how to do anything on your car, and will have a plethora of diagrams and images for the various systems in your car.

If you're lost on where the vacuum lines are, remember that anything in your car which uses vacuum assistance sources vacuum from the intake manifold.

Also, you will have maximum vacuum at idle, as that is when the throttle plate is closed.

Vacuum testing kit ($18):
http://amzn.to/csIobC

 

[Acanthus]

Definitely get the code, but it could be something as simple as dirty injectors.

Actually now that i think about it, i ran a bottle of injector cleaner through it about a month ago. (probably 2 tanks of gas ago) So that's out.

 

[CrackRabbit]

My 03 with the SPI motor had the same issue.
Kept throwing o2 Lean sensor codes and sputtering to the point of stalling.

Turns out there was a rubber hose that goes from the PCV to the Throttle Body, the elbow portion of it had rotted out and was sucking in tons of air.

You will have to take out the hose from the air box to the throttle body to get at it, but I will bet that is your problem.

 

[Acanthus]

Back from advanced auto.

Misfire on Cylinder 2.

The rep told me it is likely just plugs and wires needed.

Given the symptoms could this be the case?

I know this is pretty routine. Would i be able to do it myself with some basic directions?

 

[LTC8K6]

If you have individual coil packs, I'd suspect that. If not, then plugs/wires.

 

[Acanthus]

If you have individual coil packs, I'd suspect that. If not, then plugs/wires.

Well the probable causes were: Ignition Coil, Vacuum Seal, Plugs/Wires, O2 sensor.

Since it is not throwing O2 errors i think that is out. A vacuum seal would have thrown a different error as well, right? I would imagine that would also be oxygen related.

So i'm going to attempt changing my own plugs and wires, and if that doesn't 100% fix the problem ill try to get some quotes to get the ignition coil for cylinder 2 fixed.

 

[LTC8K6]

What you do is swap that individual coil with one from another cylinder and see if the error moves with the coil.

 

[3chordcharlie]

What you do is swap that individual coil with one from another cylinder and see if the error moves with the coil.

I don't *think* it's individual coils on that motor. Plugs and wires are a cheap maintenance item, and probably smart to do anyway.

Ignition coil and distributor is a good idea on an 8-year old car, depending if they've been done before, but maybe not needed to cure the current problem.

Edit - coil pack seems to take the function of a distributor, too.

 

[thescreensavers]

Actually now that i think about it, i ran a bottle of injector cleaner through it about a month ago. (probably 2 tanks of gas ago) So that's out.

uh which cleaner did you run? If it does not have PEA in it. Then it did jack.

 

[Acanthus]

I forgot to give you guys a final update.

The misfire was caused by a faulty plug. It was the factory original Iridium plugs and the gap was over double what it should have been.

The car runs like new with just plugs/wires changed.