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 :-)

I hope it's just plug wires, but might do a compression test just in case.

Good luck.

Best case a coil or 2 ate [censored], worst case it ate some of it's butterfly valves/bushings. i would check the second thing when you have it apart.

Good luck

Well I found the problem :-(

Took off the lower plenum and got to the spark plugs. Cyl 3 (if that's the middle on the passenger side) had a spark plug mashed into the tip.

The compression test showed 130-135 on all cyl (I am at 9200 feet) except for that cyl with the mashed plug. It has at 5...thus it looks like a bad valve or rings. This engine had the butterfly valves fail on it and I was able to salvage the machine but maybe part of the butterfly valve bounced around till it got in the way. Just my guess.

Pull the valve cover next?

I bought this machine with the purpose of putting the 6g72TT in. From what I know it will bolt up to the tranny. I may get started on this or rebuild the current motor. I can't seem to find anyone who has gone this swap...anyone know of any info that may be useful?

Can't help but just wanted to mention that I approve of your garage! Nice lineup there.

Glad you found us.

Cheers,
Phil

I put the plans for the 6g72TT on hold to see if I can get this guy to run again for cheap. I have plenty of body damage from playing in the snow...with trees and would really like to do the swap in a Montero that still looks good. It appears that buying a JDM motor with the wiring harness and ECU will make the swap cleaner and easier :-).

Pulled the Valve cover and found a rocker for one of the intake valves sitting in the head. I was able to put it back on and it stayed on during another compression test. No change.

I then pulled the head (the water pipe on back of the head really pissed me off!).

My guess was correct, the original butterfly valve from Cyl 1 some how got into Cyl 3 and it bounced around in there for 5K miles. Thousands of little nicks on the piston and head. Both exhaust valves were bent ever so slightly. Thus they wouldn't seat.

I consider spring to be the prime 4x4 time in Colorado and really just want to get the beast up and running quickly.

So I sourced a used passenger cyl head for $150. Assuming the used head checks out I am tossing it back together and doing a quick compression check.

The used head was in better condition than mine so I swapped some valves from my old head to the new one and installed some lifters from a 3g Eclipse (the hole is about 4 times the size...no lifter tick)

I put the timing belt back on and finished hooking everything up.

It doesn't want to start. I really don't get anything besides the motor cranking over. I can smell fuel.

I hooked up a timing light to the plug wires to see if I was getting spark. The light does go off but the pattern is not regular at all. I am not sure if it should be with the COP. I would have assumed it would fire at regular rate when cranking. I pulled the plug from cyl 5 and it looks like it is not even sparking because it appears brand new still (I know, that's a bad test)

As far as I know the following is needed for spark.

Crank Position sensor
Cam Position sensor
Ignition Resister (The trapezoid looking devices on top of the plenum)
The COP
The spark plug cables and spark plugs

My timing marks appear to line up correctly. They at not dead on but they are not off enough to be off a tooth in my opinion. I am nit picking here....we are talking about 1mm or less..

Anyone have any ideas on an order of attack. I routed my spark plug wires on the front of the engine so I can get to them easy. I also have my covers off so I can access the plugs without taking the plenum off again. I double and triple checked that everything was connected.

If it was running before the head swap go back and check every connector and sensor you removed or disturbed. Also check the sensors and connectors around the area you worked. It will be something you touched, start simple. Don't overthink it.

Thanks for posting some info.

I verified the following sensors were connected
Cam
Crank
TPS
ISC
Ignition Pack on the Plenum
Actuator for the Butterfly Valve
Injectors
etc

Everything was hooked up.

I pulled a spark plug and grounded it while cranking. I do have spark. I can see fuel in the cyl and I also tried using started fluid. It didn't even hiccup.

I pulled the window on the passenger side timing cover and verified that the timing marks lined up...not sure how to see the crank without removing the lower timing cover.

One item of note: Could I have got my Intake and Exhaust cams reversed? Would the timing marks still line up and would I get compression? There is a chance I also installed two exhaust cams or two intake cams. They almost look identical but I know the cut is different between them.

Anyone think I should be looking at the ECU or MFI relay even though I have spark.

So in Summary:
1. I have spark
2. I have fuel
3. Timing marks line up on both heads. Have not checked crank.

From what I know, even if the crank was off 1 tooth it would still start....

If you are getting unburnt fuel with spark, I would think that would indicate your timing off.

I would double check that all timing marks line up. Rotate the crank 2 full revolutions and make sure it is still lined up. The timing marks should be right on.

The FSM has a troubleshooting section for every sensor/ switch that the ECU uses to start/run. Real easy to check sensors like the crank position sensor and cam position sensor.

Did you use a new timing belt? Timing belt pre-load was set right?