Sputtering problem with 2002 mustang
 

Hey guys,
What would cause a 2002 ford mustang to sputter at 60-65 MPH? The wife's car just started doing this weird sputter on the freeway. What's funny, the RPM to don't fluctuate, the speed of the car stays the same, and power stays on the whole time the car is in motion. This is weird.

Breakdown of the car:
Ford
Mustang
auto
3.6 or 3.8 V6
everything is stock on this car.

We would appreciate any help on the subject.

How many miles are on it? MAYBE a sign of the fuel filter getting plugged up? I have my doubts about that though as you should feel a reduction in power if it was getting fuel starved. Check the basics first, plugs, filters, any loose vac lines, electrical connections...

I forgot to mention that the spark plugs, fuel pump and, fuel filter are brand new. Also, I checked the plug wires to make sure there is a connection. I will need to check the vac lines. Could this be a vac line? everything works fine until you get to 55-65...

If all of those items are new then I am lost. Unless the trouble started at the same time the tune up was done?
There is a chance it could be a vac line, but honestly I doubt it is. Do you have a scanner to check trouble codes with? That will get you right to the source of the problem. If you don't have one, maybe a shop near you will scan it for a small charge and then you can take care of the problem at home.

You are sure it is the engine you are feeling and not the transmission acting funny?

Look on the steering wheel, the problem is circled for ya! LOL!!!!! But really, I think Autozone does free code scanning still, might be a good place to start as stated above.

You found the problem!! Nice work! :rofl:

Very funny. I didn't pick the car.

Just teasing. I actually just sold a 2000 GT Mustang a couple years ago. It was my wifes daily driver for a long time. I never had the same trouble you are and I wish I knew which direction to send you in. I think a scan at this time is your best bet.

Yeah, I think that is the next step.

:cheers: You might also check for any Ford tech bulletins on this issue, just a thought.

a scanner to check the fuel trims while acting up would be best! Vacumn leak would probably show up at idle also though. Surge in idle or fords like to shutter almost take off at idle while your on the brake with a vacumn leak. I bet its plugs though. Is there a slight delay while cruising and you load it up with heavy throttle? I would just pull the plugs and check them first, bet thats where you will find your issue :cheers:

oh...forgot to read the plugs were new! What brand? Hopefully motorcraft? If there some garage like bosch or something might as well throw them away! If they are motorcraft, check gap

Yes, they are motorcraft.

If I recall correctly, this vintage of Mustang is MAF equipped (mass air flow). Air filters simply do not catch 100% = I'll bet you that the MAF sensor is dirty, which will cause drivability issues without necessarily setting codes (even highly experienced ASE Master Techs / Advanced Drivability Specialists miss this one). There should be two anti-tamper Torx screws holding the actual sensor (black plastic rectangular item) down to the MAF assembly casting. Remove the actual sensor and look for a tiny hotwire spot welded to 2 thicker pegs. Any dust, dirt, fuzz (and I mean magnifying glass visible) on the actual hot wire will insulate it from reading the appropriate amount of actual airflow entering the engine. The PCM adds fuel based upon the amount of air entering into the engine, and will skew the fuel tables to the lean side if it is reading low amounts of air to the PCM. Having said all of this, I advise you respect how delicate this sensor is. One wrong move and you will wreck it and they are not cheap to replace. This is also applicable to most all hotwire type MAF cars (there is also a siphon type design that is less sensitive to dirt) - you would be suprised how much better a vehicle can run when the MAF sensor is cleaned (providing it was dirty).

Hey wait a second, aren't you the hydroboost guy?? LOL ;)

Paul,
I give take a look at it when she gets home.

that is some great info Paul. Thanks for posting it. I will keep it in mind for any future issues I may run into.:thumbsup:

My '03 'Stang is having some idling issues so I'm gonna give the MAF a blast of electrical cleaner and see if it fixes the problem.

John

thats why being able to see the fuel trims would help out to diagnose this problem.......

Just buy your wife a new car....

Take it easy on throwing the rocks...I have seen your glass house.

The damn coil packs! The car is now on the road :)