Thread: Negative timing spikes

I was monitoring my ignition timing the other day and noticed a lot of negative timing spikes. Only thing I did was reset the ecu. Is this a normal occurrence or is there something that is going wrong. I am using a Jwt ecu. I really don't think this should be happening during acceleration. The lowest spike was negative 5.

Are you using 93 gas with that ecu? If not then your knocking and ecu is retarding the timing. Otherwise bad knock sensor

I was using 93 octane Vadim, On the other hand know sensor is good and I even paid retail for it. Which sucks because I noticed greg V had them for a awsome price and they are genuine Nissan sensors.

If the signal from the knock sensor is interrupted or there is a bad connection making the signal intermittent, below 5000 rpm the ECU pulls 5 degrees.

Dave

Did you make sure both surfaces were very clean before installing?

The only thing that explains negative dips is knock and ECU trying to save your engine. If you have too much timing in one part of the map, ECU will retard if it sees a knock. Any extra vibrations to the knock sensor can be bad too.

Did you torque the knock sensor to spec when you installed the new one?

What are you using to monitor ignition timing?

has the problem only occurred since you replaced the knock sensor?
my long gone jwt (VE programmed) ecu was famous for pulling loads of timing from~2000-3000 rpm or so. made the ve run like squat. stock ecu/maf fixed the problem

Isn't there a way to desensitise it?
I'm having issues with mine being too sensitive too, it pulls timing at torque peak (4500rpms) and it's kinda annoying because it doesn't always do it.

It's a new Nissan sensor too.

What are the conditions, other than 4500rpm, when the timing gets pulled? WOT only? Have you advanced the timing around 4500rpm?

Dave

How badly are we talking here?

Maps go from high 30's to 9* depending on the RPM'S and engine type (low compression, high comp, boost, or no boost)