Jump to content

V88 misfire issues VR6 engine


RickyRick

Recommended Posts

Hello.  Im looking for some feedback.   Or maybe someone that can take a peek at my calibration and see if im missing anything

AAA VR6 Engine, Vipec V88 ecu.

9:1 arias pistons, Rods, 288 cams, ported head with largely oversized valves

Factory 60-2 VR trigger

MSD 8224 twin post coils with factory vr6 Control module wired to vipec Wasted spark setup

borg warner s366

Running multi-group fueling no cam sensor

USRT 2000cc injectors

Electronic throttle body.

GM 3 bar map sensor (OEM)

 

I have this annoying misfire issue.  Ill try to give as much detail as possible.

Car runs fine around town.  I have driven it a good amount of miles

I can rev all the way to redline at lower loads without issue.    Ive gone to 7000+ and no trigger errors or anything of the sort.

The problems seem to start when i start using the turbo.    Boost is set at wastegate right now (150kpa)  running 93 octane.

It seems like spark blowout at above 5krpm sometimes its a very harsh unloading.  I have to abort the pull

Now, every once in a great while i can get a decent pull over 6500 out of it.  But its happened maybe 2% of the time.  There seems to be no rhyme or reason for any of it.  Ive found no patterns.

After this misfire happens.  It seems to roll over to every part of the map.  Meaning.  At low loads it starts misfiring.   The car  will generally run much worse all around. after this happens.  Sometimes itll sound like its intake backfiring here and there.

There are no trigger error counts when this happens

Sometimes the laptop disconnects from the V88

Things ive tried

Trigger settings(all), Dwell (high 3ms, low .5ms , in between) , Spark plug gap.   started at .030 and slowly made my way down to .020 , new plugs, new wires.  i tried different shielding techniques.  I even had ran a cooling duct to the area with the coils because i was desperate and thought heat might have been an issue.

Ive tried timing adjustments.  I was running very low timing on this until i got fueling dialed in.   Roughly 8 deg at 240kpa.  KNowing that this is overly safe I added a couple degrees.  didnt help.

All sensor values and logs look fine up until that point.  No erratic RPM jumps.  No erratic sensor values.    I have fuel pressure, oil pressure, IAT, MAP, Foot pedal ,TPS, ECT.  They all look solid.

Ive obsessed over this for days at this point .  I don't know if im missing something here  and  there is no reason the hardware shouldnt be able to handle this (coils) .

 

 

 

 

 

RRkyle.pcl

Link to comment
Share on other sites

It sounds a lot like electrical noise.

However are you able to take a PC log of all parameters and attach then we can take a look at what might be going on.

As you are running wasted spark make 100% sure you plugs and leads are resistive.

 

Link to comment
Share on other sites

took the car out with a spring out of the wastegate.   Running 8 psi

the car pulls through the gear now.  on the same dwell settings ive used.    This is good.   BUT

The car spun the #1 rod bearing .   Pulled the head off and it looked like at some point something had gotten in that cylinder and bounced around.      Funy thing is.    no marks on the head.   Piston has 2 dents. cyl wall looks perfect.   exhaust valve looks fine.  Turbo looks fine.       Just must have shocked the bearing enough to eventually spin it.     

That cylinder still has decent compression  But it looks like after the bearing spun.  the piston kissed the intake valve which is/was  slightly tweaked  im guessing from the object entering.

The only thing i can blame at this point is the intake manifold.  Whoever welded the flange on it left some really suspect areas.  missing welds  on the inside with large gaps filled with material that looks loose.

 

Depending on when something got in there.  this couldve been the root of the issues.    If the foriegn object got in and tweaked that intake valve first then i can imagine the car at higher boost levels wouldnt react as it should.  Especially with a leaky intake valve.  This would also lead me to believe the random backfires in the intake i heard every once in a while were due to that valve.

 

Ill get it back together and report back

Link to comment
Share on other sites

  • 4 weeks later...

try with cop coils from vag, used in skoda, audi, wV, porsche...

i had similar issues but i had trigger errors, after using this cop, never had single issue (on any car, and i tune them few :) )

and it is strange that you have damaged 1 rod bearing and no trigger errors. or you have to much spark advance, but on 93 octane fuel i think your engine would knock first, and you have no damage on pistons? im not sure anymore :(

try with COP first

 

edit, what is spark advance on 8psi now?

 

 

 

 

Link to comment
Share on other sites

It was a foreign object that caused the damage on 1.  which lead to the spun bearing.

The highest i ended up with at 8psi was roughly 18degrees.   Which is right in the correct range.   I would still consider this somewhat on the conservative side as ive mapped other vr6's on different ecu's  with much higher advance on 93

 

 

Link to comment
Share on other sites

  • 2 weeks later...

ok i see.

did you try with vw  / audi cop?

problem solved?

regarding other ecus,

i saw (i dont want to name it) ecu, where advance is set to 30deg and its only about 10 :D

on the other side, on vipec, 10 is 10 deg

but 18 deg should be fine on 8psi its not much for vr6 on 9:1

 

regards

 

 

 

Link to comment
Share on other sites

On 2/6/2018 at 5:00 AM, josey said:

ok i see.

did you try with vw  / audi cop?

problem solved?

regarding other ecus,

i saw (i dont want to name it) ecu, where advance is set to 30deg and its only about 10 :D

on the other side, on vipec, 10 is 10 deg

but 18 deg should be fine on 8psi its not much for vr6 on 9:1

 

regards

Unfortunately there is no room for the COP coils on this setup.  

I am going to try a bosch motorsports ignitor first and then i will start messing with different coils.   For some reason i just dont trust these MSD units.

And yea the base timing was set and checked for drift/discrepancies .  So software requested timing vs real world is correct  :)

 

And honestly i havent even gotten my knock gear out yet as i am not even getting the car running well enough to be tuning with it yet  lol. 

 

engine is out and getting re built.   There is a foot of snow on the ground here.  So come spring we will get this figured out.

 

 

Quote

 

 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...