Ovrated

Gents,

been chasing an ignition issue lately that i haven't been able to figure out.
put a set of Sake Bomb IGN-1A coils on my FD and have been having ignition issues since.
car is a 93 fd with street port, greddy t78, aem ems 30-1800 box, ffe rails, id1k primary, id2k secondary, etc.

i finally figured out how to set the dwell times correctly but was still having the issue.
basically it feels like the car is blowing out spark around 5800-6000 rpm and above.
it doesn't matter the boost level or the AF ratio. doesnt matter if its pump gas or e85. it has done this with all of the above.
so the other day i popped an IC pipe off and decided to half throttle the car to 6000rpm to see if i had issues with 0 boost and sure as **** it still cut out.
so then i pull over and try to just free rev it and i find its STILL cutting out just free revving it.

i regrounded it, tried 2 new sets of plugs, new battery, different alternator, different map sensor, etc etc. still had issues.

so the other day i clicked on ignition, then advanced ignition, then rotary engine setup, then options.
the box that comes up gives an option to use ign difference map with a check box and then below it is a box that says dwell alt mod, which is set at 50%.

out of desperation i unchecked the ign difference map check box and did a pull at 8psi. magically the car pulled all the way to redline with no issues! no blow out. no stuttering etc.
i was excited but even more confused at this point. i checked my coil wiring about 7 times to make sure it was all 100% and it was.
then i started searching for anything to do with the "Dwell Alt Mod" box that was at 50%. couldn't find ANYTHING about anyone changing it or adjusting it. also looked in my aem manual. couldn't find anything on it.
i downloaded every aem map i could find that everyone has posted from their rx7 and no one has changed that 50% setting.

i finally googled "Dwell Alt Mod" with the parenthesis and i pulled up an updated manual off the k20 forums..
the details it shows for the dwell alt mod and what it does-

Dwell Alt mod - % - Rotary only. 2 different specs of coil. (multiplier for 2nd dwell charge time)


the bold part is the important part.. thats basically telling me that the stupid box is cutting the ignition on the trailing coils to 50% of what the primary coils are...

i haven't had a chance to go out and test this yet, but i would like to put this at 100% to see if it fixes the issues i seem to be having..

so my question to you guys... how in the hell am i the only one to have this issue and to find this?
has anyone adjusted this percentage? if so, why and what happened? i don't want to over drive the coils and fry one or something but i also want to fix this stupid issue.

for those that are still at 50%.. if you change to 100%, would you be potentially adding power to your existing set up with no other changes????

discuss!

Ovrated

well scratch that.
called aem. they said set it at 0. no change in my issue.

anyone interested in rx7 parts? I'm about to part this thing out.

bumpstart

leave it unchecked ? it seems to have worked for you ?

scotty305

iTrader: (2)

Disabling the ign difference map should fire the leading and trailing coils at the same time... essentially zero split for the trailing coils. Are you certain your leading and trailing coil wires are all going to the correct spark plugs? Leading = Lower, Trailing = Top. Also, remember that you want to have negative numbers in the Ign Difference map, conservative numbers would be (-10) or (-15) in boost, so the trailing spark plugs are fired after the leading spark plugs.

Ovrated

I am 100% positive the wires are going to the correct plugs. i have checked it many times.
and the difference map is -14 from 5psi and up

i don't want to leave it unchecked, as i don't want to damage anything with a zero split. not sure if it will or not, but i don't want to risk it.

scotty305

iTrader: (2)

It would be interesting to set the entire ignition difference map to zero, then adjust that checkbox and see how the engine acts.


Another good way to confirm that everything is wired and configured correctly might be to temporarily adjust the individual cylinder trims for each coil, watching the timing on the front pulley using a timing light. When you edit the cylinder trim table for coil 1 you want to check that coil 1's timing changes, but timing for the other coils remains the same. Similarly, you can edit the values in the ignition difference map and check that the timing for the trailing coils moves as expected.

I haven't done this myself, but have heard of some people running zero split in boost. The engine would probably want less ignition advance.

Copeland

iTrader: (42)

Interesting find on the secondary dwell, I will check and see if it helps any on my setup and report back.

Sorry I couldn't help with the original problem, sounds like CAS skew/issues or map related since it's RPM dependent. Try taking some advanced logs with more CAS related options and see if it jumps around funky at 6k+ rpm.

Mind sharing your map so we can see what the timing figures look like?

Ovrated

I would love you have you guys look at my map and tell me if i am crazy in any area..

dl it HERE..

let me know what you guys think/find.

for anyone else stealing this map, i dont care if you use it. i am however not responsible for any damage that may occur by using this map.

I do feel this map is fairly safe and is set up rather well for the non boost areas. it may be a bit rich in boost still.

scotty305

iTrader: (2)

Are you sure the coils need that much dwell time? It looks like you are still using three ECU outputs to trigger the coils (wasted spark, so both of the leading coils fire twice per 360 degrees). That means you don't have much time for them to recharge at high RPM. The high RPM misfire might be from overcharging the coils at high RPM.

I don't know why that checkbox would make a difference, but try setting the 'Dwell vs RPM' table back to 100's everywhere to see if that helps. Can you add the channels 'Dwell Angle' and 'Dwell Time' to one of the Parameters window and save a PC log of the engine free-revving to high RPM in neutral? Try it with that checkbox on and off, it would be good to see if that's changing the dwell or not. There are options called 'Dwell Alt 1-10' and it looks like they are all turned off so I don't think the Dwell Alt Mod number will make any difference.

Ovrated

Is there a better way to do this so they have more time to recharge?
would wiring the could up in direct fire vs waste spark help? i just don't know what settings to use in the aem if i do that.

this may be the issue because i was out testing it the other night and turned the T1 coil off, made no difference. then turned it back on and turned off T2. made no difference. then turned off both trailing plugs and it still made no difference.

I have turned the table back down to 100 and it still does it.
i can get a log in a few days. i took the interior apart last night to clean it up a bit.