Drivability issues - long
My car is a '90 XR-7. About 3 weeks ago, after a weekend of constant rain, my CEL came on and I developed a miss.
I gave it a day to dryout, no change.
I had it scanned. First they thought an 02 sensor, so I had them change that. No difference. They pulled the plug on #4,it didn't look as though it was firing.
Then they thought a bad plug wire. More scanning and they figured a bad fuel injector (that was only a guess). I changed the plug wire, no difference. Idling fuel pressure is 40 lbs.
Here are the symptoms:
It appears #4 is dead and not firing. Runs the same with plug wire off.
Starting from cold, it will not idle.
Hard to get over 20mph when cold, pumping the gas pedal helps.
Warm, it idles but shakes.
Stumbles when accelerating below 1000 rpm
At cruise, you feel an occaissional miss. Actually, a little more than a miss. Almost like the ignition was shut off for a 1/4 second.
CEL goes off, once in a while, but running does not improve.
Well into boost while crusing at 60.
Acceleration is very, very poor.
Can a bad coil pack effect just one cylinder?