What controls timing on my 08 Honda?

[Roland]

So my 08 Honda Odyssey has real poor acceleration, so i live stream scanned it, and the timing retards WAAAAAy too much. It goes all the way to 10 degrees AFTER TDC!!! (when i stomp on it.) and when it does that, it has no power.

It has power and doesn't retard bad when it's cold (OL), but when it warms up (Closed Loop) retards bad.

I do have valve train noise that gets louder as i try to accelerate and i'm guessing the Knock sensor may be playing a roll. I'm thinking it's 20 degrees off at times

Anyway just trying to understand why a engine would EVER retard more that TDC

 

[StevieC]

Either your VVT solenoid is messed up, and/or the tiny oil port for the cam phaser is plugged causing the cam phaser not to work properly or the Knock Sensor is telling the computer the engine is pinging and it's retarding it. Both are not active until closed loop. Sometimes an EGR valve can cause this and the computer tries to compensate as well.

Could also be the timing belt slipped because the tensioner is messed up or if the timing belt is old and never replaced and the mileage is high.

Do you have the CEL on? A live data scan would be able to tell you.

 

[JC1]

What's the mileage on the Belt? Is the belt original?

 

[Roland]

Thanks Stevie C
, i have to look up what is "VVT" silenoid and find out more about the oil port.

The EGR is easy so i'll clean that or replace it this weekend.

I bought it with 200 K owner wasn't sure when they did the Timing belt last . I put 70k on it in the past year and a half, i was prepped to do the TB soon but now the engine noise (valve train) is getting pretty loud when i rev it up. Sounds bad like a old Detroit diesel. So im debating a engine swap instead.

 

[Roland]

Oh, Variable Valve Timing... i don't think My Odyssey has that. It has the stupid Variable Cylinder Management.

 

[StevieC]

Oh you have the one with the VCM. That's a whole other can of worms and that could be why the timing appears messed up.

You will have VVT though I'm pretty sure. There are tiny holes that can get clogged with oily sludge both in the cam and the VVTI solenoid and cause a problem or the solenoid itself can stop working.

 

[Hall]

Originally Posted by Roland
Oh, Variable Valve Timing... i don't think My Odyssey has that. It has the stupid Variable Cylinder Management.

Two different things and yours has both (I'm very certain).

 

[Roland]

You guys are right. im looking into the VVC maintenance right now maybe hit that this weekend also.

PS, No CEL (at times i do get a PO420 rear cat but before i replace the cat i wanted to correct the timing issue)

 

[StevieC]

The Cat might be just the downstream oxygen after the cat. Check that first.

As for the problem you are experiencing I would look into the VCM system first, those are problematic for sure.

 

[clinebarger]

Originally Posted by StevieC
Either your VVT solenoid is messed up, and/or the tiny oil port for the cam phaser is plugged causing the cam phaser not to work properly or the Knock Sensor is telling the computer the engine is pinging and it's retarding it. Both are not active until closed loop. Sometimes an EGR valve can cause this and the computer tries to compensate as well.

Could also be the timing belt slipped because the tensioner is messed up or if the timing belt is old and never replaced and the mileage is high.

Do you have the CEL on? A live data scan would be able to tell you.



The J35 doesn't have Cam Phasers. I view VVT & VTEC as two different things....The K24 is a example of an engine using both VVT & VTEC.

Timing belts don't usually just skip one or two teeth & stop there. The teeth on the belt tear away or the belt fails/breaks. Bringing the engine to TDC & checking timing marks is pretty easy on a J35 & would put this theory to rest.

I have seen some old Mitsubishi/Chrysler engines jump time a few teeth from incorrect belt tensoining (Cam style tensoiner pulley).

Cam/Crank position error should definitely set a trouble code!

I know you mean well StevieC......But you are NOT a seasoned technician & it shows in your posts! You didn't notice me being facetious in your Automatic Transmission thread that no one has responded to since!

 

[Roland]

I replaced the four O2's 2 months ago.
I disabled the VCM with a S-VCM controller a while ago.
With the timing off im thinking some extra un-burnt fuel is dumping in the cat so that's might be part of the random po420 codes.

It looks like the VVC is best Replaced rather than cleaned it looks like a lot to it on the 08 model but im not sure i imagine after market is ok for $190

 

[Trav]

Sounds like possibly a clogged cat. Abnormal combustion due to excess back pressure will cause noise that in turn will be picked up by the knock sensor and retard timing.
A cheap vacuum gauge can help diagnose a bad cat. Worth a look at IMO.

 

[StevieC]

Originally Posted by clinebarger
Originally Posted by StevieC
Either your VVT solenoid is messed up, and/or the tiny oil port for the cam phaser is plugged causing the cam phaser not to work properly or the Knock Sensor is telling the computer the engine is pinging and it's retarding it. Both are not active until closed loop. Sometimes an EGR valve can cause this and the computer tries to compensate as well.

Could also be the timing belt slipped because the tensioner is messed up or if the timing belt is old and never replaced and the mileage is high.

Do you have the CEL on? A live data scan would be able to tell you.



The J35 doesn't have Cam Phasers. I view VVT & VTEC as two different things....The K24 is a example of an engine using both VVT & VTEC.

Timing belts don't usually just skip one or two teeth & stop there. The teeth on the belt tear away or the belt fails/breaks. Bringing the engine to TDC & checking timing marks is pretty easy on a J35 & would put this theory to rest.

I have seen some old Mitsubishi/Chrysler engines jump time a few teeth from incorrect belt tensoining (Cam style tensoiner pulley).

Cam/Crank position error should definitely set a trouble code!

I know you mean well StevieC......But you are NOT a seasoned technician & it shows in your posts! You didn't notice me being facetious in your Automatic Transmission thread that no one has responded to since!





Where did I claim to be? I was only offering advice where to look. I never claimed to be a mechanic. I have worked on a lot of engines under a mechanic though so while I might not be a licensed and seasoned mechanic I know a lot, done a lot, and have seen a lot and if any of that can help someone who has less knowledge then me then whats the issue. It is the Internet after all. He doesn't have to take my word or anyone else's. Furthermore this isn't a mechanics board and the majority of the users here are NOT mechanics.

Furthermore it's diagnosing over the Internet which is nearly impossible without seeing the car so it's all stabs in the dark. I never said ever that it's definitely this or that, just offered advice where to look and I did ask if there were codes in the vehicle and I did offer that it was most likely the VCM he should look into first because they are known to be problematic.

Don't agree, post what you think but don't attack my posts because I offered reasonable places to look and accuse me of moonlighting as a mechanic on this board when I haven't.

 

[Roland]

clinebarger,
I think I ruled out the timing belt because the fact it runs great when cold (except the noise)

 

[clinebarger]

Originally Posted by Roland
I replaced the four O2's 2 months ago.
I disabled the VCM with a S-VCM controller a while ago.
With the timing off im thinking some extra un-burnt fuel is dumping in the cat so that's might be part of the random po420 codes.

It looks like the VVC is best Replaced rather than cleaned it looks like a lot to it on the 08 model but im not sure i imagine after market is ok for $190


Don't throw parts at this problem! It has feedback pressure sensors for the VTEC & should trip trouble codes if something is wrong in the system.

 

[Trav]

Duplicate

 

[Roland]

Originally Posted by Trav
Sounds like possibly a clogged cat. Abnormal combustion due to excess back pressure will cause noise that in turn will be picked up by the knock sensor and retard timing.
A cheap vacuum gauge can help diagnose a bad cat. Worth a look at IMO.


A cheap vacuum gauge can help diagnose a bad cat??? how?

But if the cat was clogged would it run strong when it is cold?

 

[Roland]

Originally Posted by clinebarger
Originally Posted by Roland
I replaced the four O2's 2 months ago.
I disabled the VCM with a S-VCM controller a while ago.
With the timing off im thinking some extra un-burnt fuel is dumping in the cat so that's might be part of the random po420 codes.

It looks like the VVC is best Replaced rather than cleaned it looks like a lot to it on the 08 model but im not sure i imagine after market is ok for $190


Don't throw parts at this problem! It has feedback pressure sensors for the VTEC & should trip trouble codes if the something is wrong in the system.

Yeah but there's no codes and there's a problem.

 

[Trav]

VCM issues on this engine don't act this way. It is commonly a spool valve issue which has different symptoms eg not running on all cylinders.

 

[Trav]

Originally Posted by Roland
Originally Posted by Trav
Sounds like possibly a clogged cat. Abnormal combustion due to excess back pressure will cause noise that in turn will be picked up by the knock sensor and retard timing.
A cheap vacuum gauge can help diagnose a bad cat. Worth a look at IMO.


A cheap vacuum gauge can help diagnose a bad cat??? how?

But if the cat was clogged would it run strong when it is cold?


Usually no, it would usually run bad all the time but in open loop the fixed parameters may work ok with a partitally clogged cat, once the engine goes into the closed look with the A/F monitors controlling things it might be pulling fuel.
A scan tool for the fuel trims will show this,

A vacuum gauge is one of the most important tools in the box.

https://axleaddict.com/auto-repair/How-to-Test-a-Bad-Catalytic-Converter

Edit: These are just some thoughts, it may be off but I learned a long time ago to fix what you know is wrong that may contribute to the issue and go from from there. You have a P420 which could indicate a cat issue and a problem with the cat can cause all sorts of symptoms that are common to other issues,