HunterD,


Thank you for the diagram. The timing was off and I fixed it. The engine runs fine and smooth at about 702 rpms. I let it idle for about 30 minutes and got P0173 and P0300. I have looked at post and I believe P0173 fuel trim is on bank2 which is the driver side on a left hand drive car. Do you know if it is the upstream or downstream?


The P0300 post says it could be multiple things. The 2001 Montero XLS 3.5L full size never got this code until I installed the new water pump, crank shaft sensor and fixed the timing belt marks.


Here are the readings
MAF .5 lb/min at 700 RPM
1.4lb/min at 2000 RPM


Fuel Trim at idle Bank 1
Short term +3.1
Long term +12.5
Fuel Trim at idle Bank 2
Short term +15.6
Long term +12.5


02 sensor1 Bank 1 -2.3
sensor 2 Bank 1 -2.3


02 sensor 1 Bank 2 +11.7
sensor 2 Bank 2 +10.9


Any thoughts would help. I am so tired of taking all the parts off just to get to the timing belt.


Thank you,

 

Unfortunately it looks like your timing is off. I had the same thing happen to me when i had to mess with the timing belt for the first time. The passenger side mark is a pain to align properly (you need to have a mirror and lots of good light and patience). Both codes you are getting are most likely related to that. Your timing is off just a little (one tooth probably) but it makes multiple cylinders miss the optimal firing ignition timing and thus you get the misfire. The misfire (P0300) is simply because fuel mixture exits the cylinders without being burned. The P0173 is also related to this. Your O2 sensors reading a very lean condition. Since your fuel is not being burned in the cylinder and you have a lot of Oxygen (not used up) in the exhaust. The PCM thinks you just need more fuel and dumps more fuel into the engine. However due to timing being off, it still does not get burned and oxygen is not used. That throws a P0173 code, which is System reached maximum level of adjustment available for the fuel trim increase and still not working right.

I'm 100% sure that your timing is off and nothing else is wrong. Take everything apart again. I know it's a pain, but believe me - second or third time the job is much easier. Find your timing mark on the crankshaft and align it properly. Then check both camshafts with mirror to see your marks. You MUST be looking at the belt PERPENDICULAR and not an any slight angle, otherwise you get a parallax effect and thus an error. You'll see that at least one of your camshafts if off. You are going to have to relieve tension from the belt and get it back in proper timing. After that, before assembling everything, rotate the crankshaft two revolutions, stop at crankshaft timing mark, check that and check the top marks again. If it looks good, set the tensioner and one more check before buttoning it all together. Like I said, make sure to use a mirror for checking all three marks. It is very critical.

 

HunterD,




I got time to work on it today. It was off 1 tooth on the driver side. I decided to go step by step from the instructions that you sent me. The first step is to take off the crankshaft sprocket, crankshaft sensing blade, and the crankshaft spacer. I noticed that the sensing blade had 2 pins in it and 1 was crushed. Now I am really puzzled. After reading post, I believe that the Sprocket comes with pins in it. Does the spacer come with pins also? I read that people just put new roll pins in the sprocket. Maybe that was a problem also.

 

Can't help you with the issue of the sensing blade pins and the spacer - no experience in that area. I hope someone who knows about this can chime in.
I'm glad the timing belt issue got diagnosed correctly.

 

The crankshaft sprocket comes with 2 roll pins in it. They hold the blade and spacer in place. I went to the auto store and got new ones for $5.00 and put them in. This has been an experience.

 

Sweet

Look at it as something to brag about over a beer with friends. Not too many people in this world are brave enough any more to pull a timing belt off the engine. Everyone looks at them as some sort of voodoo magic that you don't touch. Glad you got it fixed. Good job

 

The Montero runs great! I let it idle for 30 minutes on 2 different days with no codes. Then I took for a 100 mile drive and P0173 showed up. P0300 showed up before I got home. I can read live data while driving. My search shows everything from vacuum leak, O2 sensor and a rain dance. I am thinking about a new Denso upper sensor. What would be the best order to start?

 

I would focus on the P0173 code. It is likely that P0300 may be resulting from P0173. If you think you got the timing corrected, they check for vacuum leaks and test your O2 sensors. Long cranking time may indicate problems with fuel delivery too. Do you have a way to test fuel pressure?

 

Hunter,
Thanks for the help. I replaced both upstream O2 sensors because they tested bad. It passed inspection and no engine light for 600 miles.

 

You are most welcome!