Oddjob

A little off topic of the other knock sensor/control threads:

The KLR monitors the knock sensor, or the signal from the sensor goes to the KLR. If knock is detected, the manual states the the boost will be cut to approx 1.3 bar (absolute) and the timing will be retarded 6 deg. Supposedly this well known "limp home" mode is triggered by any of the various faults the KLR recognizes (knock, low/excess boost, TPS, KLR faults).

Im assuming the KLR will cut the boost by sending a different cycle signal to the cycling valve.

But how is the timing retarded? Does the KLR send a signal to the DME to use a fault ignition map (6 deg retarded timing) in the DME chip? The KLR has no control over ignition or fuel curves, correct?

If so, is this fault ignition map programmed into most of the aftermarket chips, or just the factory EPROMs?

toddk911

MMM, good question. Also, if timing AND boost are pulled back that much, how do so many in here have blown head gaskets at one point in time???

As from my understanding, most blown head gaskets were not someone just turning up the boost to 25 psi then banging on it like a jack ***. It was a simple situation of running a little to lean and/or hot then detonation, then head gasket.

If timing and boost are pulled back, how have so many blown head gaskets?? Unless this answers the question that this feature is not in aftermarket chips.

Bengt Sweden

The ignition signal goes from DME to KLR and modified back to the DME according to factory drawings. There is most likely no map just a time delay.
Bengt

crazyracer

Blown head gaskets come from using a different KLR chip which eliminates or alters the knock control.

toddk911

ok, I did the tap on the intake test with my GURU chips and it stumbled, so I guess they have some knock control, maybe just not as much safety margin as stock.