[big gear head]

I just bought a '02 Mustang 3.8 5 speed. It's in very good condition, but it has a misfire when it gets under a load. When I start up a hill or just push the pedal to the floor it has an occasional miss. I put in new plugs and wires, but it still has the miss. Could it be the coil? Is this a comnon problem? Thanks.

 

[Yadkin]

I just bought a '02 Mustang 3.8 5 speed. It's in very good condition, but it has a misfire when it gets under a load. When I start up a hill or just push the pedal to the floor it has an occasional miss. I put in new plugs and wires, but it still has the miss. Could it be the coil? Is this a comnon problem? Thanks.

Plugs and wires were the most likely culprit, so you done good to change those out. And you are right, the coil is the next most likely. I'd check the low voltage side to it first though, specifically loose or dirty connections.

Are you sure that this happens only under load? Does it happen at idle, on rough roads at speed, or under high rpm? Are there any OBD2 codes present?

 

[big gear head]

No codes. I checked that first. I have only noticed it under load. There are a few hills that I have to go up every day and that is where I notice it the most. I also notice it if I try to pick up speed quickly. I haven't had a chance to check the fuel pressure yet, but I think it is probably an ignition problem. There is oil around the terminals on the coil. I don't lknow if someone tried spraying WD40 in it or if there is oil coming out of the coil. Are there any other coils that are the same as the 3.8 Mustang?

 

[Yadkin]

No codes. I checked that first. I have only noticed it under load. There are a few hills that I have to go up every day and that is where I notice it the most. I also notice it if I try to pick up speed quickly. I haven't had a chance to check the fuel pressure yet, but I think it is probably an ignition problem. There is oil around the terminals on the coil. I don't lknow if someone tried spraying WD40 in it or if there is oil coming out of the coil. Are there any other coils that are the same as the 3.8 Mustang?

Some folks think that WD40 is for everything. Its not for electrical contacts, nor is it the best stuff to loosen rusted bolts (but that's another subject).

Take off the connectors to the coil, both low and high voltage, and clean everything up with an aerosol electrical contact cleaner. After that's dry a little dielectric grease on the plug wire contacts, both on the coil and plug side, will help to keep water out. Follow the low voltage wires under the hood and clean those out as well.

If that doesn't work you should find out what other contacts the WD40 was used on and clean those. It wouldn't hurt to clean the fuse connectors, ECU contacts, etc.

 

[big gear head]

Are there any other Ford cars or trucks that use the same coil? I'd like to pick up a spare coil and swap it out to see if it makes any difference. I'll try cleaning the connectors and see if that helps.

 

[wmburns]

Try this. Go to www.oreillyauto.com and look up the part for your model year car. In the compatibility tab, there is a list of all other cars this same part fits.

 

[big gear head]

I can't find the compatibility tab. Where is it located? List: Coil - 2002 Ford Mustang | O'Reilly Auto Parts

 

[wmburns]

Dude you have to select a part. Any part. Under the part's picture are two tabs. "Product details" and "Compatibility".

 

[big gear head]

Got it, thanks. Looks like over 100 that will work.

 

[blkmstg01]

+1


Sent from my Autoguide iPhone app

 

[shinerstang]

A mis-fire under load is usually a clogged fuel filter or dirty MAF.......

 

[big gear head]

I replaced the fuel filter when I changed the plugs and wires. The old filter had dirt in it. I also used a bottle of injector cleaner. I blew out the MAF with air when I replaced the air filter. It seems to be getting better. I haven't noticed it in the last few days. The weather has also been better. It's been about 10 degrees cooler and the humidity has been lower. I don't know if that has anything to do with it or not.

 

[big gear head]

Shiner, I see that you run at Beech Bend. Are you there often?

 

[big gear head]

Miss fire has gone away. I guess the injector cleaner and new fuel filter fixed it.

 

[shinerstang]

Shiner, I see that you run at Beech Bend. Are you there often?

Haven't done any racing this year. I was too busy with other cars, and just got home from the hospital. We always make the NMRA's in October......:bigthumbsup

 

[knightofthewind]

i would replace the coil pack, my mustang had the same problem and i did it and it fixed the problem...its what the spark plugs plug into...it wasent that expensive fix to me.