Adjusting the ignition timing

I was talking to someone about remapping the G13BB Jimny. We were discussing modifying the base timing using the trim resistor but searching through Google for a link I found no information on this so I wonder how many people have actually checked their timing. The FSM does explain how to do it but it seems that many people believe that its not adjustable. For information I've compiled a table of the stock resistor values and part numbers:

Part Number, Mark, Resistance (ohms), Advance (correction)
33926-76G10, 1, 0, -5
33926-76G20, 2, 82, -4
33926-76G30, 3, 160, -3
33926-76G40, 4, 270, -2
33926-76G50, 5, 430, -1
33926-76G01, N, 680, 0
33926-76G60, 6, 1000, 1
33926-76G70, 7, 1500, 2
33926-76G80, 8, 2200, 3
33926-76G90, 9, 3600, 4
33926-76GA0, 10, 6200, 5
33926-76GB0, 11, 12000, 6


There should be a sticker on the timing cover that indicates which resistor is currently fitted. Timing advance should be fixed using a jumper in the monitor coupler before checking timing. It is possible to fit a variable resistor in place of the fixed resistor.

Edit: My apologies for the formatting - it looks OK in the editor.

Another way you can do it with the G Series engines is to slightly drill out the 3 allocation/mounting holes bigger for the Cam Sensor Housing. I put the G16a in my Jimny and still wasnt happy with it running at 10 degrees. Drilled out these holes a couple of mm bigger and it allows you to rotate the cam sensor like a distributor. Put a timing light on and you are good to go. Think the most i could get was 13-14 degrees However. It made the world of difference in performance.

If i remember right you could only drill a couple of mm bigger before hitting the o'ring seal. Still enough to slightly rotate the cam sensor housing enough to bump up (or down) the timing a little.

Still Rhinoman's way is best.

Hello, the timing correction is very interesting.

whereas gasoline that the engine G13BB was designed differs substantially from that used currently

in joint work with carlos (carlos hma from chile) experimentally determine the optimum ignition point

Factory ignition point



Carlos hma replaces the original fixed resistor for a variable resistor (lineal 20kohm)






And the ignition timing is adjusted while driving

Found the ignition point works best satisfies us, we replace the variable resistor for a fixed one.

Cheers

Gustavo

Rhinoman wrote:
There should be a sticker on the timing cover that indicates which resistor is currently fitted. Timing advance should be fixed using a jumper in the monitor coupler before checking timing. It is possible to fit a variable resistor in place of the fixed resistor..

would say there is no reason why you could not fit a 10k 25 turn pot/trimmer to replace the resistor that's fitted.. something like this:

LINK

The manual say s the ignition resistor is behind the glovebox but have you got a photo of where the sticker is as I cannot see one on mine

Resistor in my jimny. (LHD)



Marked with number 2

You could use a variable resistor like that one, the CO adjusters fitted on General market models are just that mounted to a connector. This one is from a Swift:




There should be a sticker on the timing cover like this one (borrowed from the net):




You need to be cautious when experimenting with the timing but if it hasn't been checked then there could be gains in power and economy from getting it set to the stock settings.

How do you know what number resistor to get or do you just keep trying until it feels better?

You need to check the timing and then note how far out it is. If it is, for example, -2 degs then you should check the resistor currently fitted, if its a 2 degree resistor then you need a +4 degree resistor.

Can someone please confirm for me, is this the Timing Trim Resistor?
it has number 4 on it.
After bridging the monitor coupler and using a timing light, I got the figure of "0" TDC.
Can someone please shed some light on which resistor I need to purchase to get my timing back to stock "5 BTDC".
also where to purchase from. I live Adelaide South Australia

Thankyou
Blackie

First Time Poster.

As far as I can tell you need to add 5 degrees to the timing, you already have a 4 which is -2 degrees so you would need a +3 degree which would be an '8'. The difference should be quite noticeable.
You could pick up a 2k2 1/2W resistor and connect it using spade terminals to test that, it would be a cheap test.

Rhinoman wrote: As far as I can tell you need to add 5 degrees to the timing, you already have a 4 which is -2 degrees so you would need a +3 degree which would be an '8'. The difference should be quite noticeable.
You could pick up a 2k2 1/2W resistor and connect it using spade terminals to test that, it would be a cheap test.

What wattage variable resistor would you recommend for testing purposes?

1/2 watt would be more than sufficient. If my memory is to be relied upon then the value of the resistor is only read at key on so you can't adjust it on the fly.