Goob

Hey all, I just purchased a 2004 Mustang V6 3.9L.....

Heres the story. Got it home and it was idling rough at about 30-40 mph - took it to O'reillys to check for error codes (check engine light did come on). did have a couple error codes as in Cyl 3 was missing. I replaced the engine coil with a new one I purchased at O'reillys.... At this point it got bad. The car now wouldn't even get power enough to make sound like it was going to turn over.

So, I put back on the old coil thinking the new one may just be bad. Now, I did number the plugs so they would go back on the same.... So, here I'm scratching my head - the darn car won't turn over at all now! It sounds like it might (which is better than the new coil sounded) but it just wont turn over! UGH.

Any ideas what may be going on?

Thanks!

BabyGT

Okay. Let's clear some things up first. Idle is only what the car does at a complete stop without touching the gas. When you say turn over you mean start? That's actually two different things. When you turn the key does the motor spin at all? That's turning over.

Have you checked the plugs? Could be a whole list of issues.
Go for a full tune up, plugs, plug wires, fuel filter, air filter, see what that does.

When buying a coil never buy the OEM spec replacements, only ever get Motorcraft or a respected brand like MSD. I'm at work at the moment so I can't get to my car to give you a wire layout for the coil.

PNYXPRESS

How old is the battery? Sounds like the starter isn't getting any power to spin the motor. Also check for loose or cut wires

JeffBall

Could be the alternator decided to crap out on you.. Just isn't putting out enough juice to spark the plugs and in turn not burning the fuel. (That is, if the starter is trying to crank it at all)

Goob

Hmmm, great points - sorry for the sloppy type earlier. Reading back through I didn't really say what I meant. I didn't mean idle I meant running....

It's not the battery - I went ahead and replaced that as it looked like it could need it.

The cut wires is a good thought - the silly thing is, is that it worked before I tried replacing it..... Just not as good as it should have.

The alternator is a thought that's worth checking out.

As for the tune up - Yes, agreed - that's what's needed and would be willing to take it to the shop to even have it done right but - it wont start.....

A buddy suggested going through the relays and fuses again.... Worth a shot.

PNYXPRESS

A missfire is caused by one or more of three things. Air fuel or spark

Check your maf and wires to make sure they are plugged in tightly

How old is the fuel filter? Check the connections for the injectors, both electrical and fuel lines.

Check the plug wires and plugs.for signs of arcing and separation of the wire from the boot
Also how old are the plugs and wires

PNYXPRESS

Also when you say won't start, do you mean wont start running or the engine won't turn over at all

Won't run could be a fuel or spark issue

Won't turn over is a power to starter or starter issue

Check to make sure the battery cables and starter cable are hooked up correctly and right

Goob

Thanks so far - unfortunately still no luck!

Just to clarify - The car cranks up but just doesn't want to turn over and start actually running......

So, based on that your saying a fuel/spark issue? Hmmmmm. The car has 52k miles on it so it's not lot but it is 10years old.

IronMan0002005

So the engine will turn, but wont actually start?

Goob

Yes, that is correct. It will turn... That's the strange part - it started up before messing with the engine coil. I've checked the plug wires again and again, I've reset the ECU, I replaced the battery and cleaned the conections, I've checked all the fuses twice, I reset the relays, I've double checked the fuel cut off button in the back.....

I guess the next thing to do is to check the spark plugs for spark along with the engine coil just to make sure.... I'm running out of time - I may just have to break down and tow it to the shop....darn.