Anyone familiar with Nissan DataScan?

[Ryantzer]

I finally got Nissan DataScan connected to my '90 Q45 to help diagnose failing NOx on my local emissions test. I was looking at the realtime data and the ignition timing was showing 45 degrees at idle - I don't think the engine would be able to run with that much timing advance, but I'm not sure what the number relates to. Does anyone have enough experience with DataScan to tell me if I'm supposed to be offsetting that value somehow in order to read the actual timing?

[fontana dan]

Not familiar with DataScan but I used an old-school timing light to check the ignition timing on my 1997.

[Ryantzer]

I'm not trying to set the ignition timing, I've already done that with a timing light and the method in the FSM that you showed above. I was using DataScan for the first time so I could monitor the EGR valve behavior when I noticed the ignition timing shown was nowhere near what it should be. I've since learned that other people have apparently experienced the same issue so it's some sort of quirk with the DataScan program.

[Q451990]

I think that's a quirk with all of the software. If I remember correctly, you're seeing the target timing being sent by the ECU, not the actual timing. I also wonder if what you see for EGR behavior would be an actual ECU opening, or just when the ECU is telling it to open. Maybe if you have a California model with the EGR temp sensor?

In my experience, checking the EGR is feeling for it to lift at a certain RPM range specified in the FSM at idle (it'll just lift a bit and kind of flutter) - and pushing the valve up manually to see if the idle drops. If you lift it up, and idle doesn't drop, you probably have a carboned plugged port in the plenum.

[Q451990]

From the groove yard of forgotten favorites.

91-q45-timing-question-t279759.html

[Ryantzer]

From the groove yard of forgotten favorites.

91-q45-timing-question-t279759.html

Thanks for that - I figured there was just something being lost in translation from the ECU values, and since I know my timing is set correctly via timing light and CAS adjustment I wasn't too worried about it.

[BCC93QT]

"don't think the engine would be able to run with that much timing advance, but I'm not sure what the number relates to." Just went through the same shtt.. how did you know your timing was set correctly?

[Ryantzer]

Followed the instructions in the FSM: I set the ignition timing with a timing light, using an extra plug wire from the #1 coil to the spark plug to be able to have somewhere for the timing light's inductive pickup to work.

[BCC93QT]

You know what you are doing obviously. I replaced my crank angle sensor myself. Both dog bones need to be aligned. Dont let your random mechanic do it.hmm

[UK-SRi]

Hi,

I need to look at the data for my ABS on my japanese version of the Q, what device do you use to read the data?
I would like to know what devices actually work properly on old nissans, as the internet is full of info about scanners not working for whatever reason.

Thanks,

[Q451990]

I'm not sure that we've ever seen an aftermarket scan tool or adapter that works beyond the ECU, or maybe the TCU. Once you get in to ABS stuff, we've pretty much been limited to whatever self test is shown in the service manual that gets you to a flashing light on the dash. Hopefully, I'm wrong and someone else knows of something that would work.