The harmonic balancer on the 2002 v6 vtec accord has 3 timing marks on it.Which one is true TDC for timing belt? Which marks on camshafts align with which marks on head for TDC? What is the cylinder numbering layout on the vtec engine?I cannot find this basic info in the Haynes manual.
Any help will be appreciated.

 

It is the white mark on the harmonic balancer. The cams should line up with a hash mark on the rear timing cover with the UP mark or a 1 (for TDC cyl. 1) on the cams. You may have to turn the engine over a few times before the marks all line up. Also, you want to loosen the cam bolts before you remove or cut the old belt if you plan on replacing cam seals why your doing the belt. If you don't, it is VERY difficult to remove the cam bolt without messing up your timing.

 

I am in the midst of a timing belt replacement on 2002 Accord EX V6. Unfortunately, I did not mark the edge of the camshafts before removing the old timing belt. I relied upon the vertical marks on the sprockets (the ones painted with a white dot) to align the cam shafts. i

 

I am in the midst of timing belt replacement on a 2002 Accord EX V6. Unfortunately I did not mark the edges of the camshaft sprockets before removing the old belt. Instead I relied upon the vertical hashes in the center of the sprockets (the ones with white painted dots). Then, I noticed a stamped mark in the edge of the front cam sprocket and thought I should align with that. It's real close to the vertical hash with white dot, but perhaps 1/2 notch off. After aligning with the stamped mark and running the engine, the TCS and check engine light came on and engine revving/slowing. Figuring timing was off, I reinstalled the belt according to white vertical hashes with painted dots in cam sprockets. Engine runs much better, but at high rpm in idle (2000 rpm) and revvs/slows.

Can anyone help me figure this out? I've replace timing belts on Civic 4 cyl, but this is the first 6 cyl I've tried. Really regretting not marking the cam sprockets before removal.

 

This doesn't look like it will result in a long detailed write-up, so I'll move it to General Tech.

 

I finally figured out TDC.The harmonic balancer did not have a white mark,or it had worn away, so I used the center one.When the balancer was removed, I made sure the keyway was dead center of the vertical mark cast into the block behind it.The camshafts have a mark impressed into the metal on the face on the proper tooth.This must be aligned with the vertical hash mark on the back cover.
In order to get the belt exactly right, the center,stationary idler must be loosened till it almost falls off.After everything is in proper position,and the automatic tensioner has been released, tighten the stationary idler.Recheck all three marks, cause it loves to slip a half-tooth or so after tightening.Rotate by hand several revolutions and recheck all marks.
If all is still aligned, you are in business.If the engine was out of the car, and on a motor stand, it would be less than 30 minutes to do timing belt and water pump,but the confined space makes it very difficult.
I hope my experience helps someone else with timing mark issues.
-------------------------------------------------------------------------
I had a problem with my TCS light and check engine light before timing belt change, as well as engine surging. I replaced the Idle air control valve, which was indicated by the engine fault code, but I still have a surging problem.Cause undetermined.Still get intermittent TCS light, which I understand may be caused by unequal air pressure in tires, or uneven wear on tires.This is a minor concern at present time, but the surging is very troublesome.
Does anyone know what else may cause the surging?This is a 2002 Vtec 6cylinder engine.

 

Surging idle can be caused by a couple other things, which you can check.

- Air in the cooling system (really!) That can throw off the idle-air valve as it passes through. Bleed out all the air.

- Throttle cable tight? The cable MUST go slack, and the throttle plate has to close tight. Some misguided mechanic may have used the cable, or the mechanical throttle stop, to adjust the idle RPM. That mechanical throttle-stop should only just prevent the throttle from wedging stuck closed.

- Dirt around the throttle plate?

- Set the BASE idle.
1- Warm up the engine completely.
2- Unplug the idle-air valve. The engine will almost stall, so nurse it with the throttle.
3- Adjust the idle-air needle valve for 550 rpm (all accessory loads OFF). (Verify the 550 number with a shop manual for your year/engine?)

- Force the ECU to re-learn the idle behavior.
1- Reset the ECU by pulling fuse #13 at the right-side door hinges.
2- Let engine cool down completely.
3- Start engine without touching the gas pedal.
4- Let it warm up completely without touching the gas pedal.

------------
Idle-air needle valve is #1. Idle-air control valve is #2.

 

Thanks for help I will try these steps and let you know.