tunerpike Posted September 1, 2013 Share Posted September 1, 2013 Guys, I am having some problems where when I get to a certain rpm in natural (or driving) the car starts to miss badly. Even in natural revving I get hit 10psi of boost... almost like a two step..... the miss usually start around 3700 rpm... I'm running EMS Pro which is based off MS1. Im running stock 83 dizzy with an MSD box. Any ideas?... Kinda thinking its a noise problem.. but just wanted to ask. thx Quote Link to comment Share on other sites More sharing options...
tunerpike Posted September 1, 2013 Author Share Posted September 1, 2013 just to post a little more info, if I lay into the throttle slowly as it get higher in the rpm range... say 2k it start backfiring though the intake. could this me a timing issue? Again, I really appreciate any help Quote Link to comment Share on other sites More sharing options...
winstonusmc Posted September 1, 2013 Share Posted September 1, 2013 I had the same problem and it was solved by noise filtering. It was so bad the ECU would reset itself.I just figured out what size each pulse would be at a given RPM and added a little for error. I could post up my filter curve but its for the DIY wheel. Quote Link to comment Share on other sites More sharing options...
tunerpike Posted September 1, 2013 Author Share Posted September 1, 2013 (edited) Please do.. I would really appreciate it.. Also, could you explain in a little more detail on what your talking about? where did you add for error? fuel? Thanks again. Edited September 1, 2013 by tunerpike Quote Link to comment Share on other sites More sharing options...
winstonusmc Posted September 2, 2013 Share Posted September 2, 2013 You have to figure what pulses your CAS is going to produce at any given RPM and add maybe 50% for error. I have the DIY wheel, which has 24-2. The windows are as wide as the spaces. This translated into 12-1 at the crank. Each window is 15 degrees of crank rotation. This is 417 micro seconds. I think I made it 800 just to be safe at idle. Then it tapers off as the RPMs increases. The stock CAS windows are 3 degrees if I remember correctly. Quote Link to comment Share on other sites More sharing options...
tunerpike Posted September 2, 2013 Author Share Posted September 2, 2013 I'm not seeing where I make these changes.... What is the name of the table? Thx Quote Link to comment Share on other sites More sharing options...
winstonusmc Posted September 2, 2013 Share Posted September 2, 2013 I use MS3, so I am not sure what MS1 has. It is under igntion settings ->" noise filtering" for ms3. Quote Link to comment Share on other sites More sharing options...
winstonusmc Posted September 2, 2013 Share Posted September 2, 2013 This is my table. You could use my settings if you devide the "usec" by 5 Quote Link to comment Share on other sites More sharing options...
Matt Cramer Posted September 4, 2013 Share Posted September 4, 2013 I'm not seeing where I make these changes.... What is the name of the table? Thx That setting is not there in MS1, however. Quote Link to comment Share on other sites More sharing options...
tunerpike Posted September 7, 2013 Author Share Posted September 7, 2013 Winston I really appreciate your willingness to help... During last weekend I was able to do a little tuning while someone else drove, I was able to get the car to stop missing with very very conservative timing.. I cant advance the time any past 23 degrees and once I hit boost I will start dramatically pulling back even more... By the car acting this way, does this pretty much confirm that its a noise issue? Quote Link to comment Share on other sites More sharing options...
winstonusmc Posted September 8, 2013 Share Posted September 8, 2013 No, noise would happen with any timing. I could post uP my timing curve, but its just one from the megasquirt map share. Sounds like you may be running too much timing. Quote Link to comment Share on other sites More sharing options...
winstonusmc Posted September 8, 2013 Share Posted September 8, 2013 Post up your timing table. Quote Link to comment Share on other sites More sharing options...
Matt Cramer Posted September 9, 2013 Share Posted September 9, 2013 Or better yet, the complete MSQ and a data log of the misfire issue. Quote Link to comment Share on other sites More sharing options...
tunerpike Posted September 9, 2013 Author Share Posted September 9, 2013 Guys, After playing with it today, I noticed if I fix my timing at 0 degrees and rev the motor my timing does not stay on 0 with my timing light. Does this mean my distributor has play? Quote Link to comment Share on other sites More sharing options...
Matt Cramer Posted September 9, 2013 Share Posted September 9, 2013 If it wanders around at random, yes. If it retards a few degrees as RPM goes up, adjust the latency number under Advanced -> Advanced Code Options. (If it's way off, switch Spark Output Inverted to Yes, and reset your trigger angle.) Quote Link to comment Share on other sites More sharing options...
tunerpike Posted September 9, 2013 Author Share Posted September 9, 2013 It works... Thx Matt Quote Link to comment Share on other sites More sharing options...
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