Why replace the knock sensor? If you're actually hitting those compression numbers, then your stock ignition timing will cause detonation at stock fuel mixture.

Everything is setup to run an engine at stock compresssion, and if by some weird coincidence you're getting figures 25% higher than stack, then you will be getting detonation.

Detonation can be caused by a few things and I'm hardly an expert on this. Detonation happens when the air/fuel explodes instead of burning.

Causes I can think of:

High compression or high boost
Lean air/fuel mixture
Advanced ignition timing
Low Octane fuel
Any combination of the above

-Justin

 

mine is having this same problem as well we got the timing down but tomorrow I'm gonna try all the things you guys have mentioned and see what happens.

 

Replace fuel filter, check fuel pressure.
Also the ECU could be in the "limp home" mode.

On the '93-97 Altima KA24DE, in some cases, the engine will not be allowed to rev above a certain point when a sensor failure occurs.

Or your ECU could be malfunctioning.

 

well about that aiv thing when you remove it what could you use to plug the whole cause father dont want to till we get something to plug it up with and all this other nonsense

 

Try checking your sensors such as:
TPS sensor
MAF
Coolant temp sensor
and lastly Oxygen.

If the computer doesn't see proper ranges for these sensors it will go into a safe mode and not allow you to go above 4K RPM.
It may even run really bad because the computer is making calculated guess for any sensor that is out of range.

 

yea mine idles pretty rough so it might be a sensor still havent had time to remove that via iva vai? whatever thing

 

Get your hands on a Scan Tool. It will help you out a ton. Borrow beg steel. It can tell you what sensors are saying what and what your ECU is doing with that info.

 

so did u fix your problem?...cuz i am having the same problems

 

that guy hasn't signed on for three years now. good luck man.

 

s13 are OBD I so u cant u a scan tool. scan toools only work for OBD II.. u gonna have to do it the old way.. get to the ECu and count da blinking lightz :P.. so much fun trust me i know :P..