Stock ECU Misbehaving?

[Ska]

OK I own what is in my sig.

So when I first bought the car, previous owner told me speed cut kicked in at 180kms and would not go past it, to which i have proven him wrong, on a dyno of course, got up to 193 kms before the guy running the car on the dyno backed off.

So had someone check out my ECU and he said it looked as stock as it can get.

So I went out on a private road and took it too the limit, and funnily enough I do hit a limiter I think, it tries to go, but something just hold it back, this is when the speed needle is pointing just past straigh down.

Also today noticed that sometimes I can pass the rev limiter, scared me as I usually use that as a shift guide, thought I was going a bit fast for a certain gear, looked down and WHOA 8500 rpm, but then got back to that level and hit the limiter, this seems to be sporatic and cant reproduce instantly, but it does happen and it does worry me.

So I do have a totally intact stock ECU and only the mods listed below, so why should/could the stock ECU play up like this?

Thanks!

[Craved]

that is definately a wierd one, unless the ECU has been chipped! but redline is 7000rpm and speed cust should come in just past 180km/h

any stickers on the ecu? any things plugged into ecu, my SLD is stuck to the back of the ECU!

[predator]

I've seen a few that kick past the redline a bit.. I believe it is due to the type of exhaust and a few other things. If its in neutral and you redline it (which isn't too good for the engine apparently) that is when it can do it more.

The speed cut of 180km/hr is fairly rough. .some have reported going up to 200km/hr before it cuts out the injectors. There may be some inaccuracy of what the speed the ECU is picking up and that displayed on the speedo too. Even if its only 5% at 180km/hr its going to be a bit over 180km/hr.

I wouldn't worry at all to be honest!

[strutto]

I've seen a few that kick past the redline a bit.. I believe it is due to the type of exhaust and a few other things. If its in neutral and you redline it (which isn't too good for the engine apparently) that is when it can do it more.

The speed cut of 180km/hr is fairly rough. .some have reported going up to 200km/hr before it cuts out the injectors. There may be some inaccuracy of what the speed the ECU is picking up and that displayed on the speedo too. Even if its only 5% at 180km/hr its going to be a bit over 180km/hr.

I wouldn't worry at all to be honest!

[rb25]

mine used to cut out at about 195 (reading from the stock speedo) on the standard ecu. but the 8500rpm thing is very strange indeed :s. i have no ideas there.

-rb25

[Ska]

Alrighty then, firstly thanks to all for the suggestions, I unbolted my ecu and took a look at it, nope no stickers other than nissan ones.

Yeah the speed cut does not really worry me, it is the ROM limiter that does, seem to get it to do it very often in neutral by free revving the guts outta it, but also happens rarely under load, in gear, so just have to watch it when I do give it a bit

[knore]

yea my factory speed cut is at 191, the highest rpm ive hit is 7100rpm

Ide be very worried if your revs spiked to 8500rpm!

Are u sure it was 8500 and not 7500 ?

[Ska]

Yeah, positive, did not stop there either, it just sailed past then I looked up to concentrate on the road, and whacked it into neutral as fast as I could, when I looked back down, it was just coming down past 6,500, scared the living crap outta me! Thoughts were, "Oh crap what have I broken now!"

[JAS-25T]

is the stock rev limiter a fuel cut?

wouldnt that lean the motor out at high rpm and shag it?

[Craved]

jason, pretty sure it cust the spark, hence the puffs of black smoke out the back when it happens