Bitz - MS1 Extra - EDIS question

[wreckah]

hi Gary, thanks for your input,

i added the 5° static advance to the CDI+ curve to come up with the map above...so this is what i was running before the swap...of course i had sortof a stuck vacuum advance, so maybe i was running 5° more advanced all the time who knows.
yep, a lot of ignition maps on this board, but bit hesitant to just copy those and run with it. Don't want to wreck a rebuilt engine.

bitz is only fuel, so no ignition. and CDI+ = CDI with little bit programming possible. (simple curve, not a map)
parameters are not exactly easy to copy from ms1 to ms2...plenty of different parameters, but my experience tells me 13-14 AFR = happy engine...but that was with an innovate LC1 which i don't trust at all...

and yep, VE table is nowhere, haven't really started tuning yet. still studying about all the different parameters in MS2 extra.

cheers, Jan

[mytoy]

Jan

Yes that was my error in forgetting that the Bitz system was fuel only. Upon saying that I would still utilize the Bitz fuel map to start with. It should give you a more stable fuel map and you can adjust from there.

Here is an ignition map that I used to set up my system on mega squirt 2. I reduced the numbers by 2degrees as I had a higher compression ratio.



You could reduce the numbers by 4degrees to feel safer and utilize the highest octane level available just to be safe.

Note: I set the timing in the area of idle (around 45kpa) to the same from 700 to 1000. I set up my table to include the 1000 rpm and stopped at your 6400 rpm. You do not need the 8400rpm column unless you intend to rev that high.

[wreckah]

thanks gary,

ran this last night, and more or less the same story. I'm still thinking hardware issue (weak spark)
gonna add a ground lead straight to the battery and see if that helps.

[wreckah]

mimiced the VE table from my bitz setup, and in neutral it starts and runs sortof as before, revs nicely...but it won't make power...MAP signal is good, all temps are good, WUE is working fine, etc...
the car reacts very sluggish to torque demand...spark feels like blowing out or reducing or something.

[wreckah]

put an extra ground from my main ground point to the engine, also grounded the coilpack base just to be certain, grounded pin 4 of the EDIS unit to signal ground as well (not necessary), and still the same.

[jjeffries]

I'm far from being knowledgable about this stuff, but it sounds to me like you're saying the engine will rev under no load, but is "bogging down" under load. Accurate? Forgive me if you've already covered this, but when that happens, what is happening to the timing... is it advancing? And can you see what the mixture is doing via your AEM gauge? Best of luck...we all want to see you succeed. John

[wreckah]

Hi John,

yes, that is sort of accurate.
The engine starts fine, runs fine, revs fine, sounds fine, AFR's are somewhere in a decent range (12-15), MAP reading is good, advance is good, temps are good, WUE is working, etc...all while standing still. It reacts to throttle stabs relatively good, even tho there is no AE yet.

The moment i try driving it, it falls on it's face: no power, the engine doesn't really stumble, but there is imbalance, like running on 4 or 5 cylinders, but less pronounced. The car shakes a bit, you feel it in the whole chassis...and of course no real power, nowhere in the rev range. I don't dare going much higher than 3.5k, but there simply is no power and the engine shakes.
If is cruise, it almost feels fine. 3k rpm, in third, no issue. almost smooth.
that's why i've got this 'weak spark' idea...sparking just fine free-revving, but not sparking very good under load. Mixture looks fine, even under load.

As of now, there are a couple of possibilities still in my head:
- injector leaking or something...they're 1.5yrs old so maybe not
- spark plug cables look cheap to me, and are too short, 1 or 2 cylinders are quite tight.
- maybe i already fouled the new plugs?
- maybe some setting in MS that is not right. (injector dead time, ignition input capture)
- maybe an unused wire needs to be grounded ? ...

cheers for thinking along,
Jan

[wreckah]

took out one of my KTM 990 COP's to try it on the porsche engine, it's a denso 129700-4571 and it fits quite nicely...that's a route i might take to do away with the spark plug wires and EDIS coilpack...get a 2nd EDIS unit, and go COP.
i had to take a plug out to take the cap off, and it's black (dry black).

[jjeffries]

How much work to put your distributor back in and see what difference that makes?

[wreckah]

impossible, it's completely broken...adjustment bracket broken off and innards worn...

[jpnovak]

How are you verifying your spark angle and trigger offset? Are you using the trigger wizard, the "fixed spark angle" setting in timing or setting a value on the table?

There is sometimes some weirdness with changing a spark setting and the requirement of a power restart during the process to make the setting stick.

This sounds to me like your timing is off.

What worked best for my uS installations is to set the timing table to a fixed value. Then adjust the angle offset so that it matches the table at idle. Then rev the engine and adjust latency so that the timing stays consistent through the rpm band. You willl probably have to add some advance at higher rpms to get the engine to run smooth enough to get a good latency measurement.

[Jonny H]

How long is the pulse length (dwell time) to the EDIS coil? Too short and you’ll have a weak spark which will falter under load.

Most 911 engines will run and drive ok with a fixed timing of 20-25 degrees, they will just have a high idle. I’m not suggesting you leave it like this but if you just fix the timing and still have the problem under load then the problem is NOT the timing.

[scottrx7tt]

I would check to make sure the EDIS module is receiving the spark angle word. If nothing is reveived the EDIS module only sends 10 degrees advanced to the spark plugs for a “ limp home mode”

[jpnovak]

Originally Posted by scottrx7tt

I would check to make sure the EDIS module is receiving the spark angle word. If nothing is reveived the EDIS module only sends 10 degrees advanced to the spark plugs for a “ limp home mode”

Yes. Exactly! This is why I was asking the question.

[scottrx7tt]

I may be wrong, but I don’t believe you have the ability to adjust dwell with EDIS. At least I have never modified the dwell settings

Originally Posted by Jonny H

How long is the pulse length (dwell time) to the EDIS coil? Too short and you’ll have a weak spark which will falter under load.

Most 911 engines will run and drive ok with a fixed timing of 20-25 degrees, they will just have a high idle. I’m not suggesting you leave it like this but if you just fix the timing and still have the problem under load then the problem is NOT the timing.

[wreckah]

indeed, in microsquirt, dwell = standard dwell, or fixed duty, and i don't think it changes anything. the EDIS controller sets the dwell.

i verified the timing by setting my timing light dial to 0, setting microsquirt to fixed timing at 0°, perfect, then again at 10°, perfect. (i made marks on the pulley to check with a 'static' timing light...one tooth = 10°)
I change over to ignition map, and i see the pulley advance very nicely.
i will check today with trigger wizard.

will also clean the plugs today, and order a new set (will take a few days).

[wreckah]

took all plugs out, 5 of them dry and black, but one looks brand new! i feared the worst (burnt valves, hole in piston...), but compression looks perfect, so probably a bad plug, bad plug wire, or bad injector...we'll get there.

[wreckah]

seriously, somebody slap me, found out that the one injector connector came off somehow, must have happened when changing spark plugs or so...

it's official: i'm stupid.

more testing later.

[wreckah]

Hallelujah...we're back! power is back, all seems well. Engine runs beautifully on all 6. smooth smooth smooth, what a relief. Just a stupid little injector connector! Can't believe how little you can feel that when the engine is idling or free revving.

now i can start tuning properly. Already the car feels much more stable than before.

[rwest]

That’s great, way better to be humbled by a simple problem than to be right about a major one!