[Timing Help] Checked my timing today - it is all the way advanced and shows...

[ktm]

....7 degress BTDC. It is fully rotated clockwise. I have not checked my timing since I bought the car in March.

The PO installed an electronic ignition, but I do not know what kind.

The car idles and drives fine, but I know that something is not right and want to fix it (this is not my primary car).

After doing some reading, I understand that it could be one of a few things:

1) Worn out springs in the dizzy (unlikely to be this worn out though).

2) Dizzy rotated 180 deg.

3) Oil pump spindle installed incorrectly.

I am leaning heavily towards number 3 with 2 a close second.

Am I on the right track? Suggestions?

1972 Datsun 240z - Bone stock

Currently in the midst of a re-freshening

[jmortensen]

Just to make sure, you do know about BOTH adjustments, right? There is one on one side of the distributor that is kind of hidden, uses an 8mm bolt I think. Then there is the more visible one with the 10mm bolt.

If that 2nd adjuster doesn't allow enough movement, then it is definitely #3. If the dizzy is 180 out it will barely run, and since the timing slot isn't 173 degrees around you wouldn't be able to get even close to 7 degrees BTDC. Pretty common for this to happen when swapping distributors or pulling the timing cover IME.

[Arne]

Where is number 1 lead on the distributor cap? My car have the pump spindle off one tooth when i got it, and number 1 was pointed towards the radiator cap. When I corrected it, number 1 points almost straight forward.

[Maddos]

Just to make sure, you do know about BOTH adjustments, right? There is one on one side of the distributor that is kind of hidden, uses an 8mm bolt I think. Then there is the more visible one with the 10mm bolt.

Could you please explain what the two adjustments are for. I mostly have only been adjusting timing with the hidden 8mm one and the Haynes manual isn't too specific in it's instructions.

Also after i had my head off, I managed to get my distributer 180 deg out of wack and believe me the engine won't run. It'll just cough and backfire thru carbies. To get car going (before fixing properly) found where rotor was pointing for no.1 cyl TDC and changed distributer leads to suit but now my timing reads about 40 deg advanced??? I'll fix it properly soon. I've already pulled the oil pump out and set up as explained in Haynes but with same result. But as engine is running ok except for being able to adjust timing properly will do for now.

[jmortensen]

Both bolts allow the distributor to turn. IIRC the 8mm bolt allows more movement than the 10mm. Most people just use the 10mm and don't even know about the 8mm. As to your problem maddos, screw the manual. Adjust it one more tooth and you'll be fine.

[Maddos]

Thanks for the tip. I'll probably still have to make the oil pump go 180 to get number one pointing forward again. I'm with you, it may be a guide but if it doesn't work will have to make it up as I go.

[ktm]

I used the 8mm bolt (the one that is up-side down) to do my major adjustments. The dizzy is turned completed clockwise with this adjustment.

Arne, if I remember correctly, my #1 lead points towards the radiator (though it may be cocked towards the radiator cap - I am not sure at the moment).

I'll check the second adjustment bolt.

Thank you for the help.

[beandip]

KTM , If you have a ZX ignition and the PO used the 240 bottom of the dist. the part that actually bolts to the block. The 240 part will not allow you to properly set the timing . The position of the plate where it connects to the dist is in a different position on the 240 part from the ZX dist. you dident say what ignition you have. Gary

[ktm]

Thanks for the insight Gary.

The ignition is unknown as well. A nondescript black box with a nondescript blue coil.

I may have to call the PO and inquire as to what ignition and dizzy they used.

[Arne]

Is the nondescript black box mounted on the side of the distributor? Or to the inner fender?

[ktm]

Inner fender, right below the coil.

[naviathan]

Could you please explain what the two adjustments are for. I mostly have only been adjusting timing with the hidden 8mm one and the Haynes manual isn't too specific in it's instructions.

Did you also use this haynes manual to set the firing order? The haynes firing order is off by one or something like that.