I have a '97 Accord and I'm replacing the F22B engine with an F23A. I'm moving all of the external components from the F22B to the F23A (distributor, brackets, intake, exhaust, etc.) as recommended by the shop that sold me the engine. I have the Honda shop manual, but, in the section that deals with ignition timing, one step shows you how to adjust the timing by rotating the distributor. However, in the next step, it says that ignition timing is not adjustable and if the timing is incorrect, you have to replace the ECM. I'm confused again by the manual. So, which is it - adjustable or not?

Thanks in advance.

 

Not adjustable but that's a unique year for that. It'scCommon for books & such to get that wrong.

 

Are you using the 97 ECU, or a 98-02 ECU?

Here is the way I think about this, and I may be dead wrong.

On the 97 accord:

The timing is controlled by the ECU. It can advance or retard the timing over a certain range, lets say from -1 to +1.

When you install the distributor, you want the distributor to be physically set at zero, so the ECU can advance or retard the timing over the entire range (-1 to +1). If you had the distributor physically set to +1, then the ECU could not get to -1 (it could only get to zero). That is why you would fine tune the timing.

On the 98-02 accords, the engine computer must be able to adjust the timing over any range. Or the specs on the distributor were tight enough that fine tuning was not needed. The distributor on the 98-02 does not have the slots to fine tune the timing.

I hope this makes sense.

 

I think the 97 uses about the same timing sensors as the 98, in other words the timing is triggered by the sensor down at the crankshaft. So if you rotate the distributor, you're not rotating the actual sensor that's controlling the timing. This is a case where not all 5th-gen are the same...

 

I'm using the '97 ECU. I checked the crankshaft position sensor part numbers for '97 and '98 and they're the same. I think I now know enough that I can stop being paranoid that the timing is going to be all messed up when I swapped the distributor over.

Thanks, gents.