Engine misfire?

Had a misfire replace 1plug & 1coil. Still runnin rough. Any other ideas

Cylinders 1-3-5-7 are on the drivers side. first I checked for continuity between the primary and secondary circuts on all ciols and found 0.0 omhs. Then I found constant 13.5 v on the negitive side by putting red lead of volt meter to positive power. On positive side of coil connecter I got a intermitent reading from 5.2v-10.6v. Each coil has different colored wires. If the PCM did quit I don't think then truck would run at all. Would a comperesion test be in order to see if there is proper conditions for smooth idle?

check for a vacuum leak then have a pro do a freeze frame with his scanner these are very hard to find. also check fuel pressure with a gauge auto parts rent it.

Based off some other issues I am having. Like white exhaust in the morning & loss of coolant. (It's not leaking did a pressure test)
Could be the head gasket?

yes head gasket can leak in other places besides coolant area. check compression all the way around on this. but you are losing coolant so it may very well be

I have a 1998 durango with a 5.2L. It has a #1 Cylinder misfire and the Light is on with said code. I have done a tune up (plugs,wires,cap,rotor,air,fuel,pcv) and cleared the code. The light came back on during the second drive cycle. I pulled the injector rail off checked the fuel injectors by comparing fuel spray pattern and #1 looks no different than the others and injector has a normal pulse width. I then did a compresssion check and all cylinders including #1 were 150#- 160# on two complete test cycles. Except #8 cylinder was 90#-120#.
Could the low compression in #8 be causing a #1 cylinder misfire code in the ECM? Also when I accelerate the blower air goes from the dash vents to the floor vents and as soon as i let off the gas it returns to the dash vents? Could this also be related to the misfire code?
I have had a chevrolet truck in my shop that had a #3 misfire and it ended up being the downstream O2 sensor on bank two. Could my problem be a o2 sensor? I hate to just start changeing o2 sensors $$$$ any help would be awsome thanks.
ERIC

I would think that #8 would miss. That cylender would cause a miss I would think. As far as #1, the only thing I can think of is a vacuum leak. I base that off of the problem you have with the vents. THey are actuated by vacuum. If the air changes direction under a load, that is caused by a vacuum leak because under a load, the intake vacuum drops. If there is a leak, that is when the vents will change. It could be under the hood or the dash. That is where I would start checking.

I have a 2000 Dodge Durango 5.9 4X4 about 50,000 miles on a dodge rebuilt engine, with a problem I cannot seem to isolate. Symptoms are: spark plug in cylinder 7 will foul after 2 months, the plug looks good, its the plugs threads which gets a build up of what looks like a caramelized gas mixture and this goes all the way to the plugs compression ring with some of the material on the compression ring. I have replaced dist. cap and rotor twice, plug wires twice, spark plugs 3 times, Champion Iridium. Compression test, high cylinders around 145 -150
with cylinders 5 & 7 being the lowest at 135. Test preformed 4 revolutions on each cylinder, all plugs out throttle closed. I have tried injector cleaner, no change. I have talked to several local mechanics locally who scratch their heads and say "never heard/saw that before" My fear is that there is a crack in the head at the threads, your thoughts... If you need a photo of the spark plugs, I can provide later today. Thanks in advance Mike Wywias

Since 5 and 7 are next to each other I would lean toward a head gasket failing between the two

Read the post.......... Dodge rebuilt engine...... someone has already been in there once