Unstable Timing

[ELM'sLX+CHL'sDX]

Hi Guys:

I'm having trouble passing smog (High Nox) because the timing is off on my 89 LX (Manual 4 dr). The guy at the smog station said my timing was 33 btdc. The timing is too advanced creating too much nox.

While I had the vehicle for a brake fluid flush, the Honda tech said that the timing was not stable and it was jumping around. He got it down to around 23 degrees btdc but could go no further. I've run the test on the Vacuum Advance diaphram and have replaced Thermovalve B. Still same problem.

Funny thing is though, my inductive timing light wont display the timing on the flywheel however, it shows it just fine on my 89 DX. The digital timing light however does show the timing on its own display. Are there any other components, I should check out? A loose timing belt was mentioned but I can hardly believe that would be the case, especially since the car doesn't have any driveability issues.

Any help is appreciated.
Thanks,
Claude

[Oldblueaccord]

Very good chance the timing belt is loose and making the timing jump some. Take the top plastic cover off and see if it has any slack in it.

I would look towards the distributor/cap rotor etc.

Any normal timing light should work on our cars unless your running some kinda after market ignition.

As far as the high nox probably gonna have to go for a new catilitic converter but hopefully a little tuning will get it.

wp

[POS carb]

first you have to make sure your base timing is right, 4*
then you hook up the main vacuum #2 hose, it should go up to around 15*
the secondary vacuum adds about another 3* of advance when the engine is cold, there should be no vacuum when it's warm. For my smog test mine was getting vacuum at both ports so I put a beebee in the extra hose to plug it up and still appear stock for visual inspection

If you can't see the marks make sure your TDC marks line up (put the #1 cyl to TDC and check the "up" mark on the cam gear and the pointer on the flywheel should be right on)