Nistune Forums

I'm having a very strange problem when the engine is warming up. At random points between first starting the car and the engine reaching a certain temp (close to warm) my timing just falls flat to 15btdc. The timing simply goes from what ever normal timing value (usually between 30-50 depending on the map and temp advance) and flops down to 15btdc for a few seconds. This has been verified with a timing light and with the nistune logs. I have found no pattern related to chts, afm, rpm, anything. It only happens seemingly randomly until the engine reaches a certain temp. Obviously it has an affect on driveability and I'd like to figure it out.

What I would like you guys to do is to just do some warm up logs for me to see if this is an issue that anyone else is having.

starts at 30ish goes to warmed up......

Would you mind posting the bin that was used?

I think it was this one.......I haven't changed my warmup stuff for a while, so it shouldn't matter.

no idea why...........around 1:45 to timing suddenly drops to 15degs.

Good to know I'm not the only one. Now we just need to figure out whats going on.

What condition was this in (driving, parked) and how did it feel?

I was driving. The car went quite a bit richer, from low 13 to low 12. It doesn't bog but it's very sluggish. I basically got into the car and drove, I usually let it warm up for a couple of minutes before heading out.

is this a same issue without the board installed? just curious. shoudln't have affected anything but just in case

I'm almost certain this happened long before I installed nistune. Nistune simply allowed me to log the timing change which verified my suspisions. The only other thing that I can think of is something to do with the z32 maf or not having something (EGR, AIV) connected.

Bryant, I have had a similar issue to what you describe but I have not logged it, I'll try to get one within the next couple days. It occasionally happens on my way to work in the morning, but is very brief during a flat cruise down my road so I either dont notice or just ignore it.

You guys should try trace the RAM bytes 0027 and 003E when this occurs and note any correlation/record data.

I spent a little time looking through this, but cant do much else without running simulation, those are couple bits of data I would check first.

So did anyone figure it out?! umm... why did everyone just stop posting about it?

Sorry to drag up a REALLY old thread, but i believe I am having a similar problem.

At the present the engine is in the car with no EGR, AIV or O2 sensor. It is a project car so I actually can't hook up those sensors as yet.

Has there been any more info on this one?

I haven't altered the standard map in any way and can see this occuring.

This happens because upto x temp, x rpm and x tp scale, the timing is held to the idle map. I'm not sure if Matt has found/released the addresses yet for the z31. I use a z32 ecu on my s130 and have removed the parameters completely.

Its definitely something on my list to look into. Its also something we don't notice on the RB30s which use the same ECU as the VG30s

I'm wading through RB30 assembly at the moment, I'll have a look around the timing area of the VG30 code tomorrow and see if I can find some clues