[s-cars] 1.8Tcoil pack symptoms

[John Tilden]

I had it on initially, but have removed it since the first stalling issue.
Have I over heated the coils and damaged them? My car runs pretty nominal
with regard to Temperature, and Seattle is not a HOT place thermally!

The point raised in the previous post was dwell time not voltage.
But if the 1.8T has the same range of dwell time/angle as the AAN then there
should be no issue. Has anyone compared the dwell time for the 1.8T to the
AAN?
I don't have the tools to do so, nor the specs for the coils or the output
voltages for the coil drivers.

Again it may be some other failure, just looking for alterantives. The
failure is not throwing any codes however! Damnit!

John

----- Original Message ----- 
From: "Javad Shadzi" <javad at 034motorsport.com>
To: "John Tilden" <j.n.tilden at comcast.net>
Sent: Thursday, June 01, 2006 7:50 PM
Subject: Re: [s-cars] 1.8Tcoil pack symptoms


> John, are you running the stock coil cover?  We've only seen this when the
> stock coil cover is installed.  Otherwise, we have cars with 10k miles
> running our kit with no problems.  There is no "voltage" problem as has
been
> suggested, the 1.8t and AAN both use the same basic high side coil trigger
> voltage.
>
> Thanks,
>
> -- 
> Javad Shadzi
> 034Motorsport
> www.034motorsport.com
> (408) 910-5289 - Cell
> (510) 657-6707 - Shop
>
>
> On 6/1/06 7:44 PM, "John Tilden" <j.n.tilden at comcast.net> wrote:
>
> > Hi Paul,
> > Well, that makes sense!
> > So why me and not everyone else?
> > I do have a chip in the car, but I doubt that the dwell time was changed
any
> > differently than anyone elses if at all.
> > Timing yes, dwell why?
> > But I appreciate your ideas especially since the coil/core is
significantly
> > different from the original.
> >
> >
> > Hope you don't mind me forwarding your post to the list.
> >
> > Javad, Any comments or thoughts?
> > How about a new chip to modify the dwell if required?
> > My coils get very hot, but I thought it was from the proximity to the
valve
> > cover (like inside!).
> >
> > John
> >
> > John Tilden
> > Tilden Consulting Services
> > 2820 164th Ave N.E.
> > Bellevue WA 98008
> > (425) 881-2895 Office
> > (206) 240-5318 Mobile
> > j.n.tilden at comcast.net
> >
> > ----- Original Message -----
> > From: "Paul Gailus" <gailus at mindspring.com>
> > To: "John Tilden" <j.n.tilden at comcast.net>
> > Sent: Thursday, June 01, 2006 6:37 PM
> > Subject: Re: [s-cars] 1.8Tcoil pack symptoms
> >
> >
> >> John,
> >>
> >> I'm guessing that your coils could be getting hotter because
> >> the drive signal from the AAN ECU probably has a higher
> >> dwell time than the signal from a 1.8T ECU.
> >>
> >> Most pencil coils like the 1.8T ones have a lower inductance than our
> >> OEM coils which use the traditional E-I core lamination format.
> >> So because V=LdI/dt, the dwell time needed for the 1.8T coils
> >> to ramp up to full current is probably smaller.
> >> I'm guessing that it's in the 1 to 2msec range vs. about 3msec for
> >> our OEM coils. It would be interesting if someone could verify this
> >> by measuring the drive signal from the ECU on a 1.8T car.
> >>
> >> The 1.8T coils very likely go into current limit once the current
> >> has ramped up to a preset value (probably about 10 amps or so).
> >> To achieve this current limit, the voltage drop across the internal
pass
> >> transistor has to increase substantially in order to allow the voltage
on
> >> the coil primary to be correspondingly reduced.
> >> This will increase the power dissipation on the transistor.
> >> If someone could put a current probe & scope on the supply line to a
1.8T
> >> coil conversion, it could be verified whether this behavior is
happening.
> >>
> >> I'm not sure if the dwell time on the AAN Motronic ECU can be adjusted
> >> or not. I seem to remember someone mentioning that there may be a
> >> custom timing chip on the board.
> >> Alternatively, one could use a monostable circuit and some logic to
> >> eliminate some of the beginning portion of the ECU pulse
> >> while leaving the end time of the pulse essentially the same.
> >> This would reduce the dwell without affecting the timing.
> >>
> >> Running the 1.8T coils on something less than full battery voltage
> >> could also help, but this would require a voltage regulator of some
type
> >> to do it properly.
> >>
> >> Regards,
> >> Paul
> >>
> >>
> >> -----Original Message-----
> >>> From: John Tilden <j.n.tilden at comcast.net>
> >>> Sent: Jun 1, 2006 1:20 AM
> >>> To: s-car-list at audifans.com
> >>> Subject: [s-cars] 1.8Tcoil pack symptoms
> >>>
> >>> My car, after the 1.8 T coil conversion, has been dying after running
on
> >>> warm days,
> >>> It starts to die at stop lights and as the car slows between shifts
and
> > then
> >>> finally dies an refuses to start again until it has cooled off.
> >>>
> >>> It started doing this immediately after the update, I was/am convinced
it
> >>> has nothing to do with the coils, but my mechanic is convinced it is
due
> > to
> >>> the coil swap.
> >>>
> >>> We replaced both the timing sensors at the flywheel and I got a good
week
> >>> plus out of it before it died again, of course today was the hottest
day
> > in
> >>> a week in Seattle, you know, 75F!
> >>>
> >>> It appears to lose spark, fuel pressure is OK, but no spark until cool
> > down.
> >>>
> >>> I haven't notice the cold start problem that others are reporting.
> >>> I have removed the Coil cover.
> >>>
> >>> Any ideas?
> >>>
> >>> John
> >>>
> >>> John Tilden
> >>> 1995.5 S6 Avant Europa Blue
> >>> Bellevue WA
> >>> j.tilden at verizon.net
> >>>
> >>>
> >>> _______________________________________________
> >>> S-CAR-List mailing list
> >>> S-CAR-List at audifans.com
> >>> http://www.audifans.com/mailman/listinfo/s-car-list
> >>
> >>
> >
> >
>
>