how can a coil start to fail?
Driving home from derby, a 30 - 45mins depending on lead weighting
Some 10mins into journey, the car suddenly felt flat....
okay i was loaded with a boot full and 4 people in car
But the engine drove there sweet as a nut and it drove fine to start with as well
But it went ""flat"", Engine light came on, and slowly it lost speed from cruising/cruising+ to about 55 / 60mph with foot to the floor
Suddenly, the car jolts and takes off like a rocket again, power returns and i get to cruising speeds easily
At this point i was running on 3 / 4 cylinder i assume
A few minutes later, its gone again, then back, then gone
Come to some lights and off the throttle, the car struggles to idle (hits 400 / 500rpm) and recovers
Some more lights and stop starting, the car starts is worse now, its seriously misfiring
Before i know it - it sounds 2 cylinder like, and no power at all
3mins of 2cyl i called it quits, arranged family to take passengers home and called RAC
Typically as the car cooled, the misfire "cured" itself, regardless onto the flat bed it goes
Home and diagnostics P0351 AND p0352
the p0352 was me doing the coil test at road side
Confirmed no spark cyl1 atleast
I went outside again this morning and cleared all codes, and let it idle up, it was fine and dandy * annoyingly*
Went out to go for a drive, started the car and it was straight onto 2cyls
P0351 recalling
At idle the power came and went
With
MES running i watched charge time
Both coils about 2.3ish milliseconds
When coil A failed (1 and 4 cylinder) It was around 3ms charge time
it'd cure up again
So i know its a dead coil however
Testing the coils earlier based on autodata info which is
Low tesnion Pin 1 + 2 = 0.49 - 0.6ohms
High Double HT = 6660 - 8140 ohms
i got the following
Good coil Low = .5ohms
Good coil High = 7160 ohms
Bad coil low = 0.6ohms (JUST IN)
Bad Coil High = 7090ohms
The hotter the coil got - the more extremem the failure
So for me 2x New coils and HT's + Sparkies
Ziggy
with a lead foot and loaded it was drinking alittle but thats fine and perfectly normal for mine
