Any Ford Mustang experts here?? Engine misfire. Read details.?

Question

I took my car the mechanic and they diagnosed that cylinder 1 is misfiring. I believe them because that's what the computer scan showed. I replaced the spark plugs, wires, and coil (so far) and it still misfires. Before I replaced my coil, it would backfire (I hear "pa pa pa pa") and the misfiring is only bad between 40 and 60 miles per hour. AFTER I replaced the coil with a new one, the backfiring is gone but the car misfires at any speed especially when I heavily push the gas pedal. The computer scan gave me code P036 which is "Engine Misfire on startup" (Doesn't tell me much). I put in fuel injector cleaner, but with no success. So here is what the car is doing:

-When I put my car into the "R" or "D" gears and keep my foot on the break, the car shakes badly (it also does that when I first start the car.

- When I heavily press the gas pedal, there is a vibration noise and the car vibrates as well. It sounds almost like there is a lot of air somewhere (Is that a clue somehow?)

- The acceleration is really slow especially when I heavily press the gas pedal.

So based on these facts....... Any ideas? Is it some kind of belt? Is it the fuel injector for cylinder 1? What is it?

Thank you.

MasTec 1970 · Accepted Answer

You did not mention if this is a 3.8L V-6 or a 4.6L V-8? The P0316 indicates that the PCM detected a misfire in the first 1000 revolutions of engine start-up (this means that you have a "Dead misfire") 
  If spark is weak on one cylinder, and good on its partner cylinder on the coil pack (cylinder #5, in this case), the problem part is either the coil pack or the plug wire. Swap the #1 and #5 plug wires at the coil pack, and see if the weak spark moves to cylinder #5. If it does, replace the coil pack. If not, replace the plug wires.  
NOTE: On a Distributorless Ignition System (DIS) system with a coil pack, the cylinders are fired in pairs by separate coils within the coil pack. Since both cylinders in a pair are fired together at the same time, the wires can be swapped at the coil pack for test purposes. The partner cylinders are normally directly across from each other at the coil pack.
 
 Firing order: http://i1127.photobucket.com/albums/l629/mastec1970/40vinXFO.png

? · Answer

I would test your coil primary and secondary resistance to make sure you got a good part.  But I'm highly suspect of the timing.  I would check it out.  You might have a bad sensor or something got out of alignment.  You should say which engine you have.

Chris · Answer

Leak down test sounds like the next step.  Symptoms also sound similar to a bad mass air flow sensor, though that should throw its own code.

ClassicMustang · Answer

Get a leak down test done to determine the condition of the cylinders..

Trending News

Any Ford Mustang experts here?? Engine misfire. Read details.?

4 Answers