Sorry for the long story. I like to give too much info instead of not enough.
The snow is melting quickly here in Colorado so I went to go play in the Mud/Dirt/Rivers of Slush that can be found all around the front range.
It seems the Monty has developed a new problem. It started after I went blasting through some snow and had to really punch the vehicle for a good 2 mins. As soon as I let off the gas I could hear the Montero begin to misfire.
I was now running on what felt like 4 or 5 Cyl's. Letting it idle was not helping so I gave it some gas and reved a few times. After about 30 sec to 1 min the problem stopped and I was back wheeling (now trying to get out of there).
Driving home yesterday I had some large hills to get up and needed to pass so I again punched the beat and held WOT for about 1-2 mins. As I was passing I began to notice that I had way too little power. I left off and the problem (misfire) appeared again. This time I was down to like 3cyl or less and it wouldn't idle. The Montero shut off and I tried restarting a few times. I had to hold the gas down to get it to start and even then it was on 3cyls or less. Eventually I did this enough while playing with the throttle to get enough power to finish the drive home. It is now in my garage. It only runs on 5ycl or 4cyl but will fire up. In other words, my problem is constant now.
Sorry for the long story but before I tear into this I have the following plan. Please correct me or let me know if I am missing something:
1. Spark Plugs were replaced about 5000 miles ago along with the lower intake Plenum, timing belt and water pump.
2. The ignition coils are supposed to be new (previous owner blamed problems from butter fly valves on coils).
3. The spark plug wires are NOT new and could be very old. The Montero runs better at higher throttle than idle.
4. I have no check engine lights
5. Valve stem steals are leaking....not a new problem.
I plan to check the Ignition coils with a volt meter, replace spark plug wires and spark plugs and look for bad gaskets...etc. I also plan to do a compression check too.
Anyone have anything else they would check? I hate that I can't check plugs without taking the lower plenum off! I am not even sure which Cyl's are firing.
I have 232XXX miles and I am basically stock. Just some tires :-)
