This is what i just posted on the AEM Forums... i was having very similar problems and C14 oct didn''t change anything for me as well. I was knocking all over the place and didn't know why. i had a post regarding an knock bug, but i found a solution, read on....



Check it out guys....
I may get flamed from you guys for this, but whateva....
Administrators and most EVO tuners say not to sync the timing because the evo has non adjustable timing. Sync only if you have adjusted cam gears. Well after some dyno time with bad results, i knew there was a problem. If you saw the thread about the knock bug i posted, then as you know, the problem was never solved. I decided to battle it out again and use some knowledge i learned from the dyno shop i work at. Start with the basics, correct.... use a timing light to see where ignition timing corrresponds to the crank. Dead on perfect @ idle, but @ 4000 timing at the crank was nearly 10-15* advanced >>>> see where my knock was coming from, too much advance up top ( Knock Controls saves another EVO )

Before assuming the cam/gears were installed incorrectly, i checked mechanical timing numerous times and it was dead on, crank marker and both cam gear to valve cover markers were on the money. At this point i can get as much as 18* of timing advance @ 7200 with solid A/F of 11.1-11.2 with 1.5* knock max. The car feels much better and definitely a lot safer. I know EVO's theoretically should have a max of 13-14 on pump, but what can i say, all cars are different right! I have another appointment next week for more dyno time with hopefully better results due to the new found timing. Let me know what you guys think about this. It doesn't hurt to shoot a timing light on the crank to verify where your ignition timing is really going so give it a shot and see what happens.

 

I firmly agree, I have given the same advice several times. The Pickup Comp Delay is what causes the ignition to jump around at higher rpm and it usually has to be adjusted.

 

same here. before adjusting we were running like negative ignition timing values! now they seem fine

 

what kind of ignition timing are you guys seeing so far with your newly adjusted values. Also what is the exact reason why AEM EMS engineers say specifically not to sycnc timing.

 

This sounds exactly like my issue. As soon as I check on it I will report back with the results.

 

yeah, that is the first thing i would try before removing and swapping all kinds of parts. EMS engineers say not to but hey, it cant hurt. Give it a shot and let us know. Start with the basics and go from there.

 

Another thing when checking the timing at the crank, its good to have the ems right next to you or have someone watching it from inside the car. Shoot the light at the crank, verify timing @ idle, check to see if it matches the aem (if not pull up the options configure timing display , set it on fine and advance or retard slowly until the tiiming in the AEM matches that on the crank. Double check it again at a higher RPM like 4500 to make sure its within 1-2* from each other. When i say 4500, change the timing there on the AEM a bunch like 10-15 degrees just to make sure it follows the signal to the crank

 

Just becuase the timing light is telling you that you are at say....10degrees....doesn't make it true. EVO's are wasted spark, and dial back timing lights do NOT pick up wasted spark correctly, because the frequency is doubled. If you adjust the base settings in the evo, since the timing is NOT mechanically adjustable, you are going to be off. It is IMPERATIVE that when you are checking and adjusting the EVO, that you make sure to NOT use a dial back light....period. The Pickup delay comp should NOT be used on an EVO either. That function is STRICTLY for mag pickups...the EVO has logic (digital) sensors, so there is NO drift on these type of sensors, as frequency doesn't change their curve. The option ignition sync only syncs up the timing(when you go into the set ecu ignition in the EMS, this is the option that gets changed) so it DOES NOT affect the timing numbers anywhere else in the ecu. I.E. if you ask for 10 degrees the computer doesn't know if it is sync'd or not, so 10 doesn't mean 10

 

Ok, now I'm totally confused. So we shouldn't sync the timing at 4500 rpms?

Why did it seem to work on his car? What else could be causing the crazy knock that keeps jumping around.

 

It didn't "work" on his car... he effectively just retarded his ignition timing to get rid of the knock. The difference is, now the numbers in the timing map aren't accurate values. The stock sync is correct, I have re-verified it on several cars, and Mark at Turbo trix check one in his shop for me as well. The base maps are correct. When you go to sync the timing and use a dial back light, all you are doing is making the timing numbers false.

 

The plot thickens... (sorry) Interesting thread! I'm going to agree with Jason. On our 06 reflash, we are keeping around 0 to -1* (or a 1* of retard) during high boost. Small bore, Evo's simply don't need the timing. They get pissed.

 

you sure all ignition trims were off when you checked the timing! I have a craftsman timing light with rotary knob and it works ok on my evo.

 

If you leave the knob at zero...it will work fine. As soon as you start adjusting it....it's over. You won't know, however, that you are off....you just....will be! You CANNOT use ANY Dial back lights with wasted spark....PERIOD!

 

Jay is 100% correct. I went rounds and rounds with Dave Buschur on the phone with this same thing. Dave basically said NOT to use the light with any knobs on it to check mine.

 

Well this SUCKS! I thought we were on to something with the knock issue. Back to square one I guess. I have changed out plugs to BR7ES, BR8ES, Magnacore 8.5 wires, turned up the amount of methanol, switched out manifolds(long story), and used race gas with methanol with no luck.

The only thing someone else suggested was to see if the knock sensor was torqued properly and didn't come loose when we changed it out. I will be checking that later today after the engine cools down. This is the last resort and I don't know what else to do. The knock is still jumping around on my car as high as 3.5 to 4.2 volts with a/f's in the 11 to 11.2 range "ON METHANOL" no matter what I try. The only thing that lowers the knock is to get the a/f's from 10 to 10.3 "ON METHANOL" to get the knock below 2.5 volts.

The AEM logs are still showing i'm only running 2 deg of timing down low and 7 to 8 degs around 7500 rpms.
ANY SUGGESTIONS? PLEASE!