13bdarren

I keep having the secondaries dropping of at a 5500rpm then a tach spike. It continues to pull after till 8300rpm does it and every load condition even free reving. I tried to upload a datalog but it was too big will make another one tomorrow.

Aaron Cake

iTrader: (1)

Post your MSQ and a datalog.

The tach spike may be noise caused by the misfiring due to the injector problem. Or the spike may be other noise which is causing a misfire and thus causing the injector problem.

13bdarren

here are the msq and datalogs notice the injector drop at around 5800rpm

muythaibxr

The secondaries won't drop unless you lose sync and RPM drops to 0. Most likely the secondaries dropping are caused by noise on the VR inputs.

Ken

mperformance

what size secondary injectors do you have?
when did the problem begin (any particular changes in your setup)?
have you changed your map recently?

I noticed that there is a big transition in your map from 150kpa to 175kpa like a big jump in fuel requirements. You also have spikes that are very consistent in your rpm range. I do have very similar spikes due to noise, but not that it affects dropping off secondaries as you describe.

Also in the datalog I cannot see anything past 5500rpm and above.

with the staging parameters you have secondary injectors should not be coming on while free reving. You have both conditions set so unless you are building over 105kpa while reving injectors should not be pulsing. Unless Im wrong.

I'm having very similar issues with my setup and I haven't gotten around on checking everything because I'm travelling too much, but my guess is either a bad coil in my case and/or bad secondaries injectors. My problem is intermittent though and started as soon as I poured an additive in my gas tank

13bdarren

I you look in the datalogs the 2nd injectors drop and primaries go way up and then the tach signal drops. If I free rev the engine is goes all nuty at that rpm range. My tach signal appears to be really clean except for this. Might be a power issue on the injectors or grounds. The car work perfect till I pulled the engine to repair a coolant seal and since the my trailling plug don't work right and I have this problem. I checked all the wiring in the engine bay to see if anything is out of sorts but don't see anything jumping out at me. Thanks for the idea keep firing away at me .

muythaibxr

did you somehow reverse polarity on one of the VR inputs and not the other?

Did you switch the input edge on either of them?

Ken

13bdarren

I am running a modded cas with missing tooth I didn't change the wires on the cas I just unplugged it and replugged when engine was put back in. I will try reversing them to see if it helps.

mperformance

13bdarren I just got home and looked at the log... I see what you mentioned. Disregard my previous post.

what happens when you drive the car at exactly at the black hole where it drops off if you keep it steady at that RPM? is it even possible to keep it steady?

13bdarren

In lower gears I can rev through it but when I get to 3rd I get lean backfires and car jurks but I can pull through it.( not a good idea but I was just testing the higher rpm) It seem to be the exact same spot every time between 5500 and 5800 my tach signal seems clean beside that. I rechecked all of my grounds can't see anything out of ordinary. ms is ground at engine,engine is grounded in 4 spot to chassis with big gauge wire. I also have a ground from starter to battery.

mperformance

crap it sounds just like my problem...only my issue happens at about 3k rpm but I ruled out the possibility of a bad transition point and I just tested today at higher RPMs and it's perfect also, went up to 11psi no hesitation in 4th and 5th. I got to datalog and see if I get similar looking graphs like yours.

Are you sure is lean backfires? or is it like my case, AFR is dead (rich) on but problem is as being intermittent (pops and hesitates at the same range all the time, but not consistently everyday) that it cannot be seen with the AFR gauge? Third gear seems to be the one that acts up too.

HAve you seen your tach go dead or move like servo controlled when this happens? I caught it once doing it, in the morning when cold and misfire was extremely noticeable. I do remember rellocating my MS unit as I recently installed the AC system in my car and I had to install the blower fan by the kick panel... hummm

SCCA RX7 RACER

Your complaint sounds like mine and I had 6 to 7 guys help me out. I looked at your settings and you have it set to O25 style read below. The post #1below was the one that set it right. The post#2 below was the reason for my problem. Post #3 was my resonse. Your problem may be the same I am not a expert in this area, it may help I do not know. Very easy to try if you think it might be the soloution. If Ken reads this he will know.

Best Regards
Kim
SCCA RX7 RACER

Post#1

Muythaibxr

I don't remember from your settings, and I am not near my laptop right now (~30 miles away from it), so can you tell me which style wheel decoder you're running? 24s9 style or 025 style?

Noise from various electrical sources can cause this, something might be causing an ignition reset for you at that rpm. Nothing else will cause the staged injection to turn off.. I've had various stuttering problems at around that same rpm when using 025 style though.

Try this: Instead of using an rpm-based switch point for staging, change over to MAP or TPS. If this is really an rpm dropout, you might still get a bit of a stutter there, but you shouldn't go lean at least.

Before doing that, if you're using 025 style for the wheel decoder, switch to 024s9.


Post #2
Quote:
Originally Posted by Eagle7
Ken, can you explain the difference between the 24s9 and the 025 wheel decoders? I've always assumed the 025 was better (because it was newer).

025 has some averaging to help get rid of noise, but I've found that on wheels of less than 36-1 teeth actually have problems with that code.

024s9 doesn't do any averaging.

Neither of them make any difference unless you're running a missing tooth. With a stock CAS you can choose either one and it won't change a thing.

Ken

Post#3
That Was It!!!!!!!!!!!!!!!

--------------------------------------------------------------------------------

025 was not the right setting once I changed it over to the other I did the Test at Idle No studder. WOW unreal,

THANKS YOU GUYS EVERY ONE IS TOPS IN MY BOOK!

Every little bit helped. Now I,m going to put back the wiring in place and do a few runs. I'll work on tuning this week and I have a race next week.

I'll Post some information for tuning for the next guy once it runs a little better.

THANKS, THANKS AND MORE THANKS,

Best Regards to all,
Kim

13bdarren

cool i will try that one it seems to make sense.

mperformance

darren any updates on this?

13bdarren

yes the 24s setting fixed it but I don't know what is going on with the trailling I need to test them again I just have them unhocked for now. Putting car away for season now. Car pull excellent till 8500 @ 15psi