Consistent C. Stradale Misfire: running out of ideas

yea, i'll clean the grounds.

I've replaced ignition ecus with another set. No cure.

 

Winter time! Temperature is about 0 celcius ( 32 F).
Now its my annual routine to tackle this problem.
New observation that I could have missed from previous winters:
1. the idle speed is about 1400rpm instead of 1700 rpm in warmer climates.
2. if I shut the car down after initial 20 second running at 1400rpm, and re-start , it will go to 1700rpm nicely.

What i'm planning to do, is to use some hot water pouches to warm up the coils before starting up and see if it still misfires. The dilemma is, my coils are new, only 1000 miles or so , and about 2 years old. If I warm up the coil and see no misfire, there's pretty much nothing I can do about it, because new coils would just be the same. Or you can treat this logic as to elimination of coil problems.

I hate to replace the ignition cable and do compression/leakdown test as those are the last thing I'd do.

 

so I used my idling f430 as a heat oven and put all 8 coils into its engine bay. after 30 min or so I took them out. Within 10 min, I installed them into my stradale that sits outside , which is around 0F degrees.
still misfires.

 

Cold compression test done.
Ambient temp: about 4 degrees Celsius.
One new, fully charged 60AH battery in one go, no recharging during the 8x crankings. ( so take that into account for the readings, maybe)
Key off after each crank to save battery.
Sequence of test: cyl 1-2-3-4-5-6-7-8
Did not remove the throttle body.

cyl 1 : 105 psi
cyl 2: 106 psi
cyl 3: 103 psi
cyl 4: 109 psi
cyl 5: 102 psi
cyl 6: 97 psi
cyl 7: 105 psi
cyl 8: 99 psi

 

the car is euro, so it only has main cats, maybe I can look into the those

 

Hot compression test done
ambient temp = 12 Celsius
idle the car until oil temp = 75 degrees celcius
removed all plugs and coils in 45 minutes.
Did not fully charge the battery, but the car was run on public street about 30 minutes after the cold test. Battery is a bought new 20 days ago. Car starts right up after the cold test and the hot test---- it has juice. Key off after each crank to save battery.
Sequence of test: cyl 1-2-3-4-5-6-7-8
Did not remove the throttle body. However, when I was testing cyl 3, I did remove the throttle body and run the test again, the pressure was kept the same.
Same pressure gauge used as cold compression test.

cyl 1 98 psi
cyl 2 97 psi
cyl 3 98 psi
cyl 4 94 psi
cyl 5 101 psi
cyl 6 99 psi
cyl 7 102 psi
cyl 8 100 psi

damn

 

No
I was thinking it is a mechanical issue, ie. low compression.
I'll have to open up the engine to determine, which I yet to have the time to do so.

 

We talked about this trev, in private, and I showed you my CS ecu dump and determined the software is the latest.

 

In the mean time, I drove an Internet pal's 360 (not stradale) last winter.
It has the exact symptom as my stradale. random misfire when cold, all good when warm.

 

skype

 

does normal 360 modena has this issue too, back in the day?

 

I wonder if the "misfire" signal was picked up by the 4x knock sensors?
How does the ecu determine it was a misfire, for this particular car.

 

I know and I do have experience with the "low idle" thing you guys are talking about..
It is TOTALLY DIFFERENT from my misfire issue.

When you have a "low idle restart will cure" issue, you are talking about sub 1000rpm cold start rpm.
When my car having the misfire, it is idling at 1200rpm-1300rpm instead of sub-1000rpm.

Also, when I say I have a "cold start misfire" , the "cold" means the environmental temp is sub 10 degree celcius ( about 50 F), in contrary to a 'unwarmed up" car startup.

I.E. If I start the car at an enviromental temp above 10C, THE CAR WILL NOT MISFIRE. This means that, in where I live, only during Nov.--March will the car misfire. In other months of the year, the car starts like champ.

From my observation,
each misfire startup I'll see a 1200-1300rpm idle, when environmental temp is lower than 10 c and car is parked overnight.
each non-misfire startup i'll see a 1400rpm idle, when environmental temp is higher than 10 c and car is parked overnight.
If my car is warmed up already, no matter what enviromental temp is, the car will NOT misfire.


TO SUM UP.
IF you live in Florida, you'll never even know the car has this misfire problem.
You'll only know the car has a mifire problem if you live in Boston. Even in boston, if you only drive the car in summer, you won't know it.