RB20 Timing Question

[skillzilla]

I have an automatic RB20 from an A31 that was converted to manula at some point in time. First off, I set my timing at 18 degrees, not knowing if it should be 15 for a manual or 20 for an Auto, since it was converted.

Second, As Im timing it, the timing marks jump around a little bit, and are shakey. When I aim the timing light at the pulley and blip the throttle it will pull timing at first then when I release the throttle it will jump to full advance (all the way to the right, passed the last timing mark).

Is it supposed to change with the throttle like that? I have an atmospheric BOV, but it didnt come with an OEM BOV so i havent had any issues so far with that.

Also check my other thread about resetting the ECU, thought this was a seperate problem though, so seperate thread.

[Joe]

you unplug your TPS when you time it?

also yes your timing is supposed to changed based on RPM. if you think about it like this it makes sense: if your timing stayed the same but RPM increased each time your spark plug fired it would have less and less time to ignite the mixture. so to get a complete burn in the higher RPM ranged the spark needs to fire sooner.

[skillzilla]

you unplug your TPS when you time it?

also yes your timing is supposed to changed based on RPM. if you think about it like this it makes sense: if your timing stayed the same but RPM increased each time your spark plug fired it would have less and less time to ignite the mixture. so to get a complete burn in the higher RPM ranged the spark needs to fire sooner.

Im pretty sure I disconnected the right plug, I have an auto to manual swapped RB20, so I have the extra plug on the front of the TPS, the one I unplugged is a 3-pin grey plug that routes off the bottom of the TPS and zip-ties to the injector harness. Was that the right one?

[jdmser]

I did my timing with the tps unpluged and my idle set at 900rpms. Set it to 15 degrees and when I plugged the tps back in it went right to 5 degrees. Did it with the tps plugged in and everthing work out fine. I have my douts about unplugging the tps when setting timing, but thats just what I did. Not telling anyone to do the same. Mine came as a 5 speed and I'll prolly set it back at 20 degrees which is where it was when I check it the first time. Feels like I lost some power at 15 degrees.

[SHIFT_Lock]

Base idle adjustment is set at 15 degree.

The Blazt consult comes in so handy during this procedure.

http://blazt.biz/

Best $114 I've spent in a long time.

Makes trouble shooting alot easier to.

Scott-