Car: 1995 Ford Contour
Engine: 2.5L Duratec
This car is driving me to drink!!!!
You start the car, it revs to 2500, tries to come down to regular
RPMs(below 1000), and then dies. If you play with the gas pedal, you
CAN get it to stay idling, but it's VERY shaky and does not sound good
At first, I thought it was an EGR problem because I had one before
with similar symptoms. But I tested the valve with a Vacuum Pump and
it worked perfectly.
Then, I noticed that the car would not stall and die if I disconnected
the IAC's air supply hose that comes off of the main air intake
system. Of course it would idle at about 1300, probably beacuse of the
New vacuum leak, but it would not die in Park or Drive. I also found
that as SOON as I hooked that IAC air supply hose back-up, the engine
immediately would stall. And I MEAN immediately!!
So, knowing this, I assumed it was the IAC valve not responding to
allow more air into the engine. I went and got a New one, installed
it, and it made NO difference at all!! This really got me mad!!
Then I decided to keep starting the car and REALLY listen closely to
hear what was going on.
I first noticed that every 20 seconds or so, I could hear this wierd
"popping" sound. It was pretty startling. Maybe a really bad lean
mis-fire. I then got in close to where the plug wires connect to the
coil and I could hear a pretty loud "ticking" sound. With the engine
running(barely), I disconnected one of the plug wires from the coil,
and to my surprise, it made NO difference at all!! I also noticed that
the spark itself was not the light blue color that I am used to with
my 3.1L Cutlass Supreme...it was more of an orange color, which may
indicate a weaker or less hot spark...which may just be normal for
Anyways, right now I have all the plugs and wires removed because I'm
going to replace them all anyways...they pretty much look like the
originals!!!(this is my sisters car)
I've measured the resistance of the ignition coil, and I'm getting 1.8
ohms, which is 3 times higher than the specified 0.45-0.55 ohms. I'm
not sure how much of a difference this will really make though?
One other thing that I'm weary of is the IAC's supply voltage. Ford
states that the VPWR should be 3.5-11.0 volts at 3000 RPMs. Well, when
I test it with my Multi-Meter, the voltage is ALWAYS 14.5, or whatever
battery voltage is at the time of measurement. I assumed that the
voltage would be variable based on what the PCM wants the idle to be