1989 Nissan Truck ignition timing


#1

I just did a head job on my truck and getting the timing is a trick. I finally have the timing correct at 10 BTDC at idle. However when the engine is revved, the timing goes to (I’m guessing) about 15-30 after TDC. This is backwards. I guess I don’t know how this distributor is supposed to advance the spark.



Can anyone describe how the distributor for this engine advances the spark? I don’t see a vacuum tube and I may have done some damage to an electrical wire, I’m not sure. But if I knew how it worked, I could trouble shoot it better.



Thanks in advance.



mspart


#2

Hopefully you have set the timing using some sort of instructions. Sometimes you have to disable the ECU control of the timing before setting it.

As far as the advance goes I would guess it is controlled electronically. Times have changed from the older years.


#3

Cougar,

I read more about it in the repair manual and it is electronic advance. So we took the wires off and they looked clean. Compression check was good too.

So I used the time honored method of timing by listening. I put it to where it ran the smoothest at idle. That happened to be about 22 BTDC. So then we revved it. It went immediately to about 15-10 BTDC before going back to 22 BTDC. It sounded great. Then I played with it a little and put it back to 10 and it did not sound so good. I put it back to 22 and we took it for a spin, my son and I. It was great, no backfiring, power as it should have. I am happy.

Thanks for sharing your thoughts. I was really stumped. I guess the distributor has a lag on the advance or something. Anyway, it is good and we are going great.

Thanks,

mspart


#4

Great! I think your engine ignition may be close to the way a Subaru is designed and they run at 20 degrees I believe. So you are where you should be it sounds to me at least and the proof is in the running.

Thanks for the feedback and you’re welcome for the help.


#5

Timing a computer controlled engine by ear is a no-no which you may discover later.

Too much advance WILL seem to make it run better. The downside is that on the highway with steady highway driving you may find that the pistons will start disentegrating and then you’re going to need a new engine.

You should use a timing light and there should be a test plug that must be jumped when setting the timing. Does the underhood sticker not specify this? The sticker always takes precedence over anything that is written in a book or what you read on the net.