Timing Advance

JBT · Postby **JBT** » Mon Oct 16, 2006 12:46 pm

2000/2001 and later except SE? No, you can't change the base timing on the NB.

JBT · Postby **JBT** » Mon Oct 16, 2006 3:36 pm

JBT · Postby **JBT** » Mon Oct 16, 2006 4:09 pm

None of the MX-5 engines have \"lifters\". The NA engines had hydraulic lash adjusters (HLA) whereas the NB engine valve clearances are adjusted with shims.

Postby **Okibi** » Tue Oct 17, 2006 9:55 pm

I thought it would only retard timing, not advance it

sabretooth · Postby **sabretooth** » Tue Oct 17, 2006 10:07 pm

Perhaps the ECU has learnt and set its base timing to 14?

JBT · Postby **JBT** » Tue Oct 17, 2006 11:23 pm

rzzzwilson wrote:What *could* be the problem?

As Sabretooth said, the ECU could be holding it. You'd need to short the TEN and GND terminals in the diagnostics box to see what the base tming is.

rzzzwilson wrote:Mistiming the cams shouldn't affect the ignition timing?

Yep, sure can. We found a B6 engine with ignition timing of about 20+ degrees BTDC. Turned out that the mechanic who changed the cam belt set the intake cam (CAS cam for a B6) off by one tooth. We reset the cam to where it should've been, the timing came back to 10 degrees BTDC where it should've been and the overheating stopped happening.

JBT · Postby **JBT** » Fri Oct 20, 2006 7:55 am

Sorry, you asked about cam timing vs ignition timing. I thought it was a general question.

Possible reasons I can think of for NB:

Crank angle sensor not properly seated/located/fitted
Crank angle sensor mounting holes elongated
Front pulley slipped - really bad news
Aftermarket ECU
Parallax error when reading timing
That's where it always was ex factory.