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A miss that I can\'t figure out
I am having a problem with a car I recently purchased. It has a miss that I can't place. Here is what I have checked and found out so far.
I have posted this on the regular ford muscle forum, but I was hoping to kill two birds with one stone here.
I drove the car in order to warm it up. It doesn't start to miss until the engine temperature increases.
-When the engine is cold, it has 15" of vacuum when
measured at the upper intake manifold
-When the engine is warm, it has 17" of vacuum at the same place
-With the engine warm, all spark plugs removed, and a battery charger on the battery, I checked the compression on all four cylinders
#1=112 #2=110 #3=105 #4=108
this is assuming that the #1 cylinder is towards the front of the car.
-When I was removing the spark plugs, the porcelian on the #3 was broken. I don't know if it was already that way or if I broke it while removing it. I don't think I did
anything that should have broken it.
-I measured the TPS with the key on and the engine off
it had .81-5.97 and the orange wire had 7.01
-I attempted to readjust the TPS and ,after messing with it
for a minute, I couldn't get the voltage to drop below
1.14. At WOT, it now had 7.56 volts
-I walked away and came back and, some how, the voltage on
the orange wire increased to 8.9 volts
Nothing was touched. I don't know why the voltage would be changing at the TPS for no apparent reason.
I disconnected the sensors one at a time, then checked the voltage at the orange wire again.
I removed the Oxygen, the sensor right by the TPS, distributor, 2 sensors on the lower intake manifold, and the 2 sensors on the ECM.
-After disconnecting the ECM, I had .05 volts at the TPS.
Unrelated---When I removed the intercooler, I noticed some oil residue on the intake side of it.
When I removed the spark plugs, they all looked a little "whitish", but not real bad. The spark plugs probably have about 300-500 miles on them.
I don't know if my problem is mechanical or electrical and I am getting pretty frustrated/confused!
What do you guys think? Just let me know and I'll check it.
Have a great day!
[addsig]
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