MS3 Random misfire

[Kennyx]

Print screen and post the miss fire , please .. i have hard time to determine it ..
Have you ever check spark power by visual... strong ? Sometime it can be the ignition cable..you running on COP or distributor ?


KennyX

[Kennyx]

Try load this msq and test.


KennyX

[kizzoalfa]

Print screen and post the miss fire , please .. i have hard time to determine it ..
Have you ever check spark power by visual... strong ? Sometime it can be the ignition cable..you running on COP or distributor ?


KennyX

I marked on the attached screen.

[kizzoalfa]

Try load this msq and test.


KennyX

Hi KennyX,

I tried to load the attached msq but the symtoms are the same. I also replaced the iginition wire set to a new one but nothing changed.

Zoltan

[Kennyx]

How is the spark energy power look like ? strong blue or yellowish ?
You change a new set of ignition wire ? I thought you are running on COP ?


KennyX

[kizzoalfa]

How is the spark energy power look like ? strong blue or yellowish ?
You change a new set of ignition wire ? I thought you are running on COP ?


KennyX

Hi,

I am running DIS cotrolled by MS3x spark outputs. I have a small module where I have ignition amplifiers, injection FET's and DIS coil control.

The Ms3x drive the ignition amplifier which contol a DIS ignition coil.

Zoltan

[Kennyx]

This is a waste spark output right ? i mean 2 plug will share 1 output ?


KennyX

[jsmcortina]

Why are you using four spark outputs from the MS3X for a two coil wasted spark system?
Why not just use BIPs? Simpler and known to work.

James

[dieselgeek]

Check that you don't have a cracked porcelain on the spark plug. Or a broken valve spring, other physical things like this. Whenever I can't find the problem in the tune, it's time to start looking at things "outside the box" - just to make sure.

[kizzoalfa]

Why are you using four spark outputs from the MS3X for a two coil wasted spark system?
Why not just use BIPs? Simpler and known to work.

James

I have used this because I wanted to go Full sequential injection and in this case the 4 cyl. even fire, full seq. injection and COP's setup can be used.

If I choose wasted spark as ignition mode will full sequential injection run or just semi seq.? If will work than which MS3x outputs will drive ignition SPKA and SPKB for the wasted spark?

As far as HW, I have good experience with the Ignition IGBT's, I was working with them as EE in the past (it was used on one of our product I was responsible for).

I will look for some HW issue outside of the box. I plan to measure and check this weekend injection currents and spark energy as well.

I already replaced Igintion wires, spark plugs, harness from MS to injectors and ignition coil.

[jsmcortina]

If I choose wasted spark as ignition mode will full sequential injection run or just semi seq.? If will work than which MS3x outputs will drive ignition SPKA and SPKB for the wasted spark?

It will do just what you ask it to do. Although dwell overlap would require very high dwells and high rpms, your circuit is "cheating" the code and un-supported.

Please set wasted spark and disconnect SPKC and SPKD.
You can also then remove the diodes and ensure your driver chip gets a full 5V (looking at the datasheet this looks fine as it is, but it does remove one small uncertainty.)

James

[kizzoalfa]

If I choose wasted spark as ignition mode will full sequential injection run or just semi seq.? If will work than which MS3x outputs will drive ignition SPKA and SPKB for the wasted spark?

It will do just what you ask it to do. Although dwell overlap would require very high dwells and high rpms, your circuit is "cheating" the code and un-supported.

Please set wasted spark and disconnect SPKC and SPKD.
You can also then remove the diodes and ensure your driver chip gets a full 5V (looking at the datasheet this looks fine as it is, but it does remove one small uncertainty.)

James

James,

I understand that it is cheating the code but in my understanding it should not be the root casue of my problem. Do you agree?
Over that the "cheat" will dissappear will it have any more benefit to redesign the input logic of my ignition amplifier over that I use the released way?
Will be there any timing change because of the code is running in wasted spark? (In this timing I mean any noticeable change purely on the IGBT's gate.)

Thanks,

Zoltan

[jsmcortina]

I understand that it is cheating the code but in my understanding it should not be the root casue of my problem. Do you agree?

I don't know. Removing that oddity will rule out one minor possibility.

James

[kizzoalfa]

Hi,

Today I made some current measurements in the car regarding Injector currents and ignition coil currents.

I checked all 4 injectors, all of them have near the same injector current waveform. I attached one of them.

I also measured the igintion currents, on various engine revolutions, current remained the same, no change, no effect of RPM on the ignition currents. (I checked both coilpacks, they are identically the same.) I attached some waveforms as well.

After some measurement I decided to increase dwell time, I increased the idle dwell time to 5,5 ms. The coils started to saturate around 6.5 ms, so I decided to use 5.5 ms.

I also removed O2 sensor again and did a free air calibration (sensor was cleaned by some low pressure air before calibration.)

After the tests I started to drive the car by enabling VE analyze live to create some base VE MAP after the O2 recal.

In the attached log you can see the rough finish of VEAL. (The result is interesting in the focus of the datalogs: somewhere I have not the AFR targets I want - like I have somewhere 1.5 and should be 13.8 - however VEAL was running but by some reason did not optimalize the VE table.

As far as misfire, I found some interesting thing again: it never happen under heavy acceleration. In the first attached LOG011 you can see that I did some "harder"acceleration, 1st, 2nd, 3rd and stop in the traffic and did some lighter acceleration, 1st, 2nd, 3rd and in 3rd aroun 3400 RPM I had the 1st misfire, you can see RPM start oscillating.

Then I decided to drive back to my garage and in 2nd gear around 2400RPM it happened again during light acceleration. (LOG012)

Does it possible that I have some lean issue while accel is just mild and not hard? I checked valves, compression they are fine. Spark gaps are fine, also spark energy looks enough.

Can you please take a look into my attached two logs? MSQ is attached. I use the new accel pump which work more realistic that the traditional mode.

Thanks,

Zoltan

[kizzoalfa]

Hi,

Today I made some current measurements in the car regarding Injector currents and ignition coil currents.

I checked all 4 injectors, all of them have near the same injector current waveform. I attached one of them.

I also measured the igintion currents, on various engine revolutions, current remained the same, no change, no effect of RPM on the ignition currents. (I checked both coilpacks, they are identically the same.) I attached some waveforms as well.

After some measurement I decided to increase dwell time, I increased the idle dwell time to 5,5 ms. The coils started to saturate around 6.5 ms, so I decided to use 5.5 ms.

I also removed O2 sensor again and did a free air calibration (sensor was cleaned by some low pressure air before calibration.)

After the tests I started to drive the car by enabling VE analyze live to create some base VE MAP after the O2 recal.

In the attached log you can see the rough finish of VEAL. (The result is interesting in the focus of the datalogs: somewhere I have not the AFR targets I want - like I have somewhere 1.5 and should be 13.8 - however VEAL was running but by some reason did not optimalize the VE table.

As far as misfire, I found some interesting thing again: it never happen under heavy acceleration. In the first attached LOG011 you can see that I did some "harder"acceleration, 1st, 2nd, 3rd and stop in the traffic and did some lighter acceleration, 1st, 2nd, 3rd and in 3rd aroun 3400 RPM I had the 1st misfire, you can see RPM start oscillating.

Then I decided to drive back to my garage and in 2nd gear around 2400RPM it happened again during light acceleration. (LOG012)

Does it possible that I have some lean issue while accel is just mild and not hard? I checked valves, compression they are fine. Spark gaps are fine, also spark energy looks enough.

Can you please take a look into my attached two logs? MSQ is attached. I use the new accel pump which work more realistic that the traditional mode.

Thanks,

Zoltan

Some more attachments: LOGFILES

[kizzoalfa]

Some more attachments: Measurement results of injector and ignition current

[Kennyx]

The problem now is .. im not sure how reliable and how proper the dwell timing to set on your ignition system...you can tweak it little by little if you have enough free time ... anyway, if you suspect the O2 will disturb your engine operation ..you can always disable the o2 correction before run .. judging from your fuel VE table .. i dont think it is cause by fuel .. i will more focus on the ignition system if i were you .. And i forgot to ask you .. is your exhaust gas looks good ? any blue , black or white smoke comes out from tail pipe when you rev up the engine ?


KennyX

[kizzoalfa]

The problem now is .. im not sure how reliable and how proper the dwell timing to set on your ignition system...you can tweak it little by little if you have enough free time ... anyway, if you suspect the O2 will disturb your engine operation ..you can always disable the o2 correction before run .. judging from your fuel VE table .. i dont think it is cause by fuel .. i will more focus on the ignition system if i were you .. And i forgot to ask you .. is your exhaust gas looks good ? any blue , black or white smoke comes out from tail pipe when you rev up the engine ?


KennyX

Hi, the ignition timing was checked many times by stroboscope and I found it OK. I also checked the ignition power by a serial device as well which has an air gap in a gas filled glass chamber and you can put it serial with the sparkplugs, no difference between cylinders, nice blue.

Right now I am am on the same opinion like you: I suspect ignition better than fueling.

My exhaust gas looks not soo good. I have Arias pistons with Totalseal rings but the engine is using some oil, however the rings were properly seated - based on my knowledge, first 2000km I had without oil consumption.

Alfa nord engines are known about they oil consumption. I am fighting with that since I know Alfa Romeo. I had originally Borgo pistons and liners but engine started to use oil. Than I changed to Arias with total seal rings, but after some monts after rebuild engine started to use oil again. I used many brands and viscosity but not helped.

Why I changed to programamble ECU because I wanted a reliable, good system. Than I found MS which is very close to engineering. I think the current oil consumption was caused by incorrect fueling caused by Motronic system what I used together by some pigy back devices I designed but fueling control was not so reliable and precise and under boost I had some oil washed from the walls by overfueling.

So, I have some white smoke under heavy load, sparkplugs look nice - here in Hungary we so call fawn clolored - but when I removed my O2 sensor for calibration I fond some black soot on the sensor and also the wall of the pipe was covered by that. (The endpipe is also black but not shiny.) I use the car mostly (99%) within the city. I think the white smoke is caused by a process that carbons start to burn under heavy load.

Right now I use around 0.8L / 1000km from oil. Engine rebuild planned this summer.

Can the oil consumption cause my issue?

Thank you.

Zoltan

[Kennyx]

Select no correction in EGO Control , do you have oil catch tank in between engine and intake manifold ? disconnect the hose from valve cover and seal the hole on the intake manifold temporary for a few test run...We will see whether your engine is drawing oil from valve cover or not, beside piston ring or valve seal.



KennyX

[kizzoalfa]

Select no correction in EGO Control , do you have oil catch tank in between engine and intake manifold ? disconnect the hose from valve cover and seal the hole on the intake manifold temporary for a few test run...We will see whether your engine is drawing oil from valve cover or not, beside piston ring or valve seal.



KennyX

Hi,

during test runs I never had EGO control enabled. Setup was run by no correction.

I do not have any hose from Valve cover into intake mainfold. The valvecover gas can flow into the free air.

I had an oil catch tank until March but I had no oil in it only some condensed water. I do not have too much gas from valve cover, compression sealaling is good.

Zoltan