Flavius424

Hello guys!

On my 231ch, I have a problem that I can not manage ...

I have missifre/hesitations between 4000tr and 6500tr
I thought it was the SSV that don't opened but not:

Tonight by blocking open the SSV, it changes nothing.
So it's not the problem...

Misfires that start around 4000tr, and which increase up to 6500tr, then nothing, it turns normally at the top ...
For me it's a failure like if it turned super rich or poor or a problem of ignition (it missfire a litle)

And of course I would not understand that it is the engine that causes this ...
My engine seems in poor condition (4.5 / 5b of compression testing with a piston compressiometer), hot start not very fine... I also found a piece of metal on a spark plug when changing the spark plug (side seal maybe ?)

New spark plug, Magnecor cables, LS coils.

It is accentuated with the heat of the engine. I would also say, it's less present with a cold/ warmup engine than with the engine hot after hard driving.

If someone has an idea of ​​where it might come from ... (I already think it can be the coil but no problem after 6500tr looks strange ?)

I woul'd like to found this problem before removing the engine for rebuild...

Thank you in advance,
Flavien

9krpmrx8

iTrader: (46)

Rebuild time.

Flavius424

Misfire before 6500rpm and running good after is caused by the low compressions ?
Very hard to understand that^^

Loki

iTrader: (1)

Perhaps not, but you mentioned difficulty starting hot, low compression numbers and metal on the spark plug. That engine has to come out anyway.

It's possible you have an injector problem, where it's not able to supply enough or supplies too much fuel before the secondaries kick in. We need data to diagnose properly, can you connect an OBD2 reader and log all sensor data when this occurs?

Flavius424

All injectors was removed for testing and cleaned with ultrasond. No flow testing anyway... but open good when powered on.

I have a bluetooth OBD 2, I have tested with the application Torque but I don't see all information and don't know to log it... If you have better application,, I can test it

Cheers,
Flavien

Loki

iTrader: (1)

Ok well the most important sensors are airflow (g/sec), Short Term fuel trim, Long term fuel trim, AFR and rpm.

Try DashCommand app, it might work better for you. Not sure if it can do logging, but search around, there are a few different OBD2 apps out there. You can also use a laptop or AccessPort if you have one.

Even if the logging consists of somebody watching or filming the data in Torque while you drive, that's better than nothing.

Without this info we're just guessing in the dark.

Flavius424

Ok thanks !

I will look that, Is an AFR sensor integred in the stock ECU ? Or I need to install an AFR gauge ?

9krpmrx8

iTrader: (46)

You need a mechanic.

Loki

iTrader: (1)

It's part of the car.

Flavius424

Ok perfect !
I haven't see this information in torques Apps, I will check with your apps

Flavius424

Hello,

I do a movie of the problem :


The sound of the missfires are not so good, but we can hear a little the problem. I have shut it down at 7000rpm because of a turn lol.

I do some log with Torques but it doesn't record the engine gauge.. (just GPS infos...)
I do a vidéo of Dashcommand log :


Not good to see...
But some informations :
Short term fuel in load : 0% all the time
Long term fuel in load : approx 16% all the time
Maf g/s in load : good reaction from 80 at 4000rpm to 210 at 9000rpm
AFR in load : 12.2/12.5 before 6500rpm, 11.5/11.8 after 6500rpm
MAP : go up to 250Kpa in load ?? why on an N/A engine ?

So, the only gauge that change after 6500rpm is the AFR that lower a little, fuel issue ?
But I think 12.2 is not a bad number number...

Cheers,
Flavien

Flavius424

Hello guys !

Engine is now out and dissasembled ^^










As you can see, a side seal is broken, see on the compression test !



Engine dissasembled :




The wear on all parts :

Rotor is good for me, just a little carbon...



Front Housing :
Big wear on it, what do you think about it ?



Middle iron :
Good !


Rear Housing :
Like the front... Not good isn't it ?



End Iron :
A little scratch because of the broken side seal, we can feel it a little by touching, good or not ?


I will take picture of the apex seal, the engine was approx 4.5b compression all the way (3.5b on the side of the broken side seal), engine normaly rebuild 32k km ago...
The low compression is because of the wear of the housing ? or other ?

Thanks a lot,


Flavien

New Yorker

I suspect you need to have this engine rebuilt - or you need a new engine.

Flavius424

If I have open the engine, it's for rebuild it :D

I have see that Goopy do rotor housing refurbishing, what do you think about it ?
The price is good, but I'm from France, the shipping cost will be expensive...

The irons are good I think, but I have see that we can resurface them if needed.

9krpmrx8

iTrader: (46)

No **** Sherlock.


Don't think, get a workshop manual (normalexception.net) and the proper measuring tools needed and spec the parts. Goopy's process is just grinding the housings, if you want the engine to last then get good used housings or new ones.

Flavius424

Thanks for your answer, I will read the workshop manual ! I haven't found it beafore^^

For Goopy, you say they grind the housing, so I don't understand what they say on the goopy website : "We are NOT resurfacing or adding new material to the housings. We are refurbishing or refreshing the existing hard chrome surface."

They sayd, he doesn't resurface the housing... Don't understant^^

Some picture after washing all parts :

Apex seals :

Some wear, isn't it ?



It's normal that they are rounded on the surface that go to the housing ?



All apex seal are in two parts ? Or some are in one piece ? what's the better apex seal make for you ?



Rotors housing :
Big wear like say before.. but by touching, not a lot of deformation.





Front Iron
One scratch on the middle of the plate, but by touching, just a little deformation near to the center of the plate.



But, a deformation near to my finger that we can feels a little (approx 0.1mm of déformation)



I will read the workshop to control it, thank you for your help !
Ans sorry for my approximative English...

Cheers,
Flavien

Brettus

iTrader: (2)

That engine has obviously been rebuilt before . The corner seals are not stock . They look like Aitkins corner seals . How many km's do you think since it was rebuilt ?

It is normal to have some wear at that point you are pointing to . 0.1mm would be ok IMO but it looks like more than that to me ...
Also , the broken side seal could possibly be as a result of the work done on the AUX port . Have a good look at the aux. ports for evidence of that .

Flavius424

Yes, I have to found the invoice to have more information but the engine had a rebuild approx 32k km ago in UK.

Yep, I think it's less than 0.1mm but I have to check with my enginer to be sure it's recurfaceable. (not read the workshop yep^^)

Work on the aux port ? porting ? what sort of problem I can see on this port ?

Thanks !

Flavius424

Some pictures :

Wear on the plate, traced with blue paint, with housing to see.
For me, it's the corner Seal who had machined the plate.
Wear is just in this section (spark plug side)




Wear on the gears Bearing :
Wear are on the top/lelt side of the engine side.






Rotors bearing seens good

Brettus

iTrader: (2)

Firstly you want to check if the side of the rotor with the broken side seal matches the side where the aux port is . If so , look closely at the port work that has been done for a sign that the side seal has somehow caught on the side of the port .

Flavius424

Ok, will check this