okay only so often when I start the car it will have a knock, when it intially starts. Sometimes not a sound. Also when going down the highway and I punch it, (automatic) it climbs but by the time its reaching around 4500 -5000 rpm it will seem like its pinging. Let off the gas it quits or when it shifts. But dont punch it, rather gradually climb it will not make a sound and rusn fine. Only when you punch it and it has the abrupt jump in rpm to 4500 -5000 it makes the noise.

I know I have the msd opti set at 2 turns out. And the accel fuel pressure at 43.

Any help please

 

What grade fuel are you using? When i use a lower octane it will ping or knock sometimes similar to your situation.

 

Pull a spark plug and look for specs on the insulator, this indicates true detonation.

 

premium gas and also with datamaster adjusting that set screw on the msd will datamaster show that? What is the stock timing at idle that I should see in datamaster. That way I can use datamaster to verify the correct timing.

 

Okay I found that I am getting knock just at the shifts. Auto. At most of 4 degrees. But It is exactly what Injuneers explaines it. So why would the map sensor cause the knock and how can fix that then.


From Injuneers website:

http://members.aol.com/InjuneerZZ/ScanMast.htm
"Using the "record" feature of the ScanMaster at WOT, many people have seen 4 to 8 degrees of retard. This is where the record features come in handy. If you hold down the recall button, you see minimum O2 level on the left and maximum retard on the right. Now hold down both the recall and mode buttons, and you will get the MPH at which the min O2 and max retard occurred, again, O2 on the left and retard on the right. Think about when this occurred. Invariably, you will find that this was at one of your shift points.

My theory (being an M6 type) is that on lifting throttle shifts, the sudden drop in MAP (remember the timing map above) on closing throttle causes the PCM to put in a few degrees more timing, and just as it has added this timing, you whack the throttle open as soon as you've got the next gear, and bang…. too much timing, here comes the retard. One way to explain it, and it tells you your motor isn't having any unhealthy problems, and not experiencing dangerous continuous knock, but still not good. Remember, it pulled all the timing back out real fast, probably overshot, and is putting it back in real slow. You are not at the better, more advanced timing."

 

You will never see any timing change in Datamaster when moving the screw on the MSD opti. Datamaster can only show what the PCM is doing with timing adjustment.

 

I'm not sure with your mods why you have done anything to the timing?

 

no no i was just tryin to think maybe the msd timing was off maybe that was screwin with it cause some ppl I read on this forum said there screw was off so I just double checked mine to see if from factory it was right.