ssgnco

Hello All,
First post to this forum. Here is the issue:
Car: 2010 TL SH-AWD, 3,7L, 6-SPD manual, 100,000 miles
Issue: Check Engine, SH-AWD, VSA, Hill Start Assist lights periodically when car is started. They can be reset and stay off for random amounts of time - a couple of drives, many drives, etc. They only come on when the engine is initially started, not while driving.
Codes: 0300,0301,0302,0303,77,83(not sure if this is the correct number, but it is the VSA code). There are never misfire codes for any other cylinders
Performance Issues: No misfires detected nor problems with performance detected. The one exception is that on one occasion, there actually seemed to be a cylinder missing for a bit when the car was started, but it stopped when the car was shut off and restarted. The graphic on the dash for SH-AWD indicates proper power distribution even with the light on.
Work Performed: The problem started after a timing belt and associated hardware (tensioner, idler, water pump, tension pulley), drive belt, plugs (Denso) replaced (I put a small amount of anti-seize on the plug threads - never had a problem doing this on other cars). The lights did not come on for first couple of starts, but came on after car sat all night in the garage). I am quite sure the timing is correct. There was a good amount of coolant spilled when the water pump was replaced.

Questions:
1. Anyone ever have this problem and know where to start?
2. How does this system sense misfire? Is it based on variations in the crankshaft speed sensed by the crank sensor? If so, could the sensor just have gotten dirty or ruined from the coolant?
3. How does the OBD number the cylinders? Do the numbers correspond to the Acura cylinder numbering? Are 1,2,3 all on one side?
4. Are the SH-AWD, VSA and Hill Start lights on just because there is a CEL, or do they share a sensor with the misfire codes? (Hoping this might narrow the search).

Thanks in advance.
Greg

ssgnco

I think I answered one of my questions. I believe cylinders 1-3 are the rear bank. This would seem to eliminate anything covering the entire engine, like the crank sensor. Could I be off by a tooth on the rear cam and only have intermittent issues with not performance problems?

justnspace

iTrader: (1)

sounds like timing is off, which could have damaged some valves?
I would recheck the work making sure timing is correct.
then I would do a pull of the negative terminal of the battery to reset the codes.

if codes come back with the same misfires, I would then do a leak down test and a compression test.
the leak down test will tell you if you damaged anything

justnspace

iTrader: (1)

Firewall
123
456
Radiator

ssgnco

[QUOTE=justnspace;15854843]sounds like timing is off, which could have damaged some valves?

Thanks for the response.

Neither cam nor the crank was moved during the job and I know the marks were aligned when I put the belt on. I followed the sequence of crank gear, idler, front cam, water pump, back cam and then tensioner. I did not verify by rotating the crank two revs (my mistake). If the timing is off, it is not off by more than one tooth. The single bank issues is definitely making me think the timing is off on the rear cam. Is the valve-piston clearance so close that one tooth would result in a hit? If so and I have damaged valve, it seems like I would have performance issues and more consistent codes. My understanding is that you need to consecutive driving cycles with random misfires to get the CEL and codes to lock in. Apparently, I'm not getting the misfires every time, which leads me to believe that there is no valve damage. Maybe a timing problem though.

justnspace

iTrader: (1)

I have a 2006 TL equipped with a six speed manual. a friend over-revved the engine and it did make piston to valve contact.
i had inconsistent misfires ranging from 1-6, but not all at the same time.
and it was def. missing at idle.

in your case, most likely piston did not come in contact with valve, as I agree maybe off by 1 tooth.
re-check the worK!

ssgnco

Yes. Not looking forward to tearing it apart again to get the covers off. At least the crank pulley bolt should be easier....

justnspace

iTrader: (1)

dont worry, I took mine apart twice.
and yes the timing belt covers were the worse!! I couldnt get access to one bolt and ended up making a mess of the cover, I broke a piece of the plastic that holds the bolt in place....

maybe this time, you could check the valves to see if they are in spec, since everything will be off anyway and you'll be checking the timing.

ssgnco

If anyone is interested, here is a great article on diagnosing misfires:


Intermittent Engine Misfire Analysis - Tomorrows Technician

Reorge

I agree with the dancing-crab-dude. Since your problem started after the timing belt (TB) replacement it's probably the most likely cause. An out-of-time TB is an easy check since there are inspection openings that are available in the TB covers.

It's very easy to install the timing belt one tooth off (as mentioned already), on the rear bank. It happened to me the first time I performed a J-engine TB replacement and I caught it before I finished. When the TB tensioner is released it can rotate the rear cam and sprocket "back" a small amount when the belt slack is removed. I now position the rear cam sprocket about a half or full tooth forward (clockwise) when I install the belt. Now when I release the tensioner is pulls the cam and sprocket back into alignment.

Keep us posted on your findings.

Skier4lyfe303

iTrader: (32)

I would check/do a valve adjustment, since that's something included in the 100K service and you didn't mention doing it. This could very well be your issue.

Reorge

Out of spec rocker arm lash on a J engine is not commonly known to cause any problem other than excessive noise. If you've had any experiences to the contrary I (we) would like to know to expand our knowledge.

ssgnco

As a follow up, finally got to this. As suspected, the rear cam was off (retarded) by one tooth. Once I got it restored, everything was fine. No valve damage. A couple of notes from my second go-round:

1. No new lesson for me, but should have made sure I rotated the crank through one rev after putting the belt on to make sure the timing was right. The crank goes clockwise and you can do it before tensioning if you are careful. If you use the bolt, make sure you put the pulley on first. Otherwise, you will never get the bolt off.
2. If you get the rear cam the slightest bit past the mark before you have the belt on, the rocker spring pressure will cause it to self rotate about 90 degrees
3. I had saved the grenade pin and tried to reuse it after compressing the tensioner. No dice. I had a tough time getting the pin out without binding. I finally used an Allen wrench attached to a good handle to give me leverage. The battery hold down bolt method is useless. Don't even bother.
4. On this car, make sure you take the shock tower tie bar off for better access.

greg