Porsche 924 Turbo ignition timing DITC system
Danny
Does anyone have experience of this. I have just had the engine
reconditioned, it runs but I think the timing is out.
The LV pulses are generated by a sensor that picks up from the starter ring
gear on the fly wheel, a constant train of pulses, hence I would assume a
constant stream of sparks. The distributor only distributes the spark to
the correct plug, nothing else.
What I cannot understand is how accurate timing is achieved.
Apparently some marks should have been lined up on the flywheel when it was
put on but as far as I see this is only to aid setting the distributor with
a timing mark that is on the flywheel.
If anyone has any ideas please post a reply or Email.
TIA
Danny.
Chris Wilson
mailed to Danny]
In article <5UTo3.11828$ts3.3...@nnrp4.clara.net>,
da...@ablott.clara.net says...
Porsche dealers sell a small technical manual for all their models, at
about 14 quid each. It lists cam and ignition timing, all torque
settings, suspension settings and adjustments, you name it. *NOT* a
full workshop manual, but I'm pretty sure it will give you the info
you require, if no one here can help. There must be some sort of TDC
reference signal, from cam crank or disi (cam again, effectively) and
an RPM sender. The ring gear trigger just sounds like an RPM
reference.
--
Best Regards,
Chris Wilson
mailto:ch...@formula3.demon.co.uk
Graham
wrote:
>Porsche 924 Turbo ignition timing DITC system
>
>Does anyone have experience of this. I have just had the engine
>reconditioned, it runs but I think the timing is out.
>
>The LV pulses are generated by a sensor that picks up from the starter ring
>gear on the fly wheel, a constant train of pulses, hence I would assume a
>constant stream of sparks. The distributor only distributes the spark to
>the correct plug, nothing else.
>
>What I cannot understand is how accurate timing is achieved.
>
>Apparently some marks should have been lined up on the flywheel when it was
>put on but as far as I see this is only to aid setting the distributor with
>a timing mark that is on the flywheel.
>
>If anyone has any ideas please post a reply or Email.
I do not have full details of this system but usually the crank sensor
picks up pulses from the flywheel (not usually the ring gear)
Different manufacturers use different methods but usually one of the
pulse's is missing to indicate to the ECU the crank position. Some use
2 sensors, one for speed and one for position. It is fairly normal for
the missing (or triggering) pulse to be many degrees (40+) before TDC
allowing the ECU time to fire at the correct point. If your timing is
way out then it could be that the flywheel has been replaced wrong,
Some engines, for example, have 6 bolt fixing and it is possible to
attach it 60 deg out if there is no locating dowel.
Perhaps if Mike Walker from ATP is reading, he may have more info, or
a search thro back postings will find his Email address. The company
ATP has a web site listed in the FAQ.
Graham
Visit http://www.hglmotors.co.uk
The uk.rec.cars.maintenance FAQ
http://www.motors.freeuk.com/faq/index.htm
Graham
>In article <37a48324...@news.btinternet.com>, gra...@hglmotors.co.uk (Graham) writes:
>
>>I do not have full details of this system but usually the crank sensor
>>picks up pulses from the flywheel (not usually the ring gear)
>>Different manufacturers use different methods but usually one of the
>>pulse's is missing to indicate to the ECU the crank position. Some use
>>2 sensors, one for speed and one for position. It is fairly normal for
>>the missing (or triggering) pulse to be many degrees (40+) before TDC
>>allowing the ECU time to fire at the correct point. If your timing is
>>way out then it could be that the flywheel has been replaced wrong,
>>Some engines, for example, have 6 bolt fixing and it is possible to
>>attach it 60 deg out if there is no locating dowel.
>
>The Haynes manual does not state if the flywheel needs to go in a
>particular place. [FX: The sound of pages being turned] Aha! I lie.
>There's a photo showing that there is a mark on the flywheel centre
>which has to align with a corresponding mark on the crankshaft end.
>It *is* 6 bolt fixing, and there is no dowel.
Hmmmmmmm I rest my case <grin>
>It also says that the
>Turbo engine does not have the toothed starter ring. How the bleeding
>heck does the starter motor turn the engine, then????
Does it say "starter ring" or "stator ring" out of interest?
JLE
Huge wrote in message <7o275a$1...@axalotl.demon.co.uk>...
<SNIPED>
>
>The Haynes manual does not state if the flywheel needs to go in a
>particular place. [FX: The sound of pages being turned] Aha! I lie.
>There's a photo showing that there is a mark on the flywheel centre
>which has to align with a corresponding mark on the crankshaft end.
>It *is* 6 bolt fixing, and there is no dowel.
Having seen others, and my self <BG>, getting court out with simular
sorts of situations I / alway / now mark flywheel etc ............It
was one hell of a big bang when it did fire, 180 deg out, felt sorry
for my workmate who droped that big bonnet on him
self......................!
> It also says that the
>Turbo engine does not have the toothed starter ring. How the bleeding
>heck does the starter motor turn the engine, then????
>
Not the old Triumph 1300 FWD way of doing thing..........surely
not<BG>
I sometimes think Haynes are about as much use as a chocolate tea pot.
__
sca...@MAPSONfreeuk.com
YOU ONLY LIVE ONCE....LIVE IT
Remove the SPAM BLOCKER before replying by e_mail
Danny
> >It also says that the
> >Turbo engine does not have the toothed starter ring. How the bleeding
> >heck does the starter motor turn the engine, then????
>
starter motor is fitted backwards on the turbo. There is a brief section
on this timing system in the supplement at the back of the Haynes maual but
it's not much help.
Danny.
JLE
Huge wrote in message <7o3j92$2...@axalotl.demon.co.uk>...
>In article <Nq2p3.9091$V21.2...@nnrp3.clara.net>, "JLE"
<sca...@MAPSONfreeuk.com> writes:
>
>>Not the old Triumph 1300 FWD way of doing thing..........surely
>>not<BG>
>
these.
>
Same shape that became the Dolimite.
Thay did two vertions the Toledo range, RWD (with shallow hub caps) &
the 1300cc/1500cc range, FWD (deep hub caps & diffrent wheels). this
had a starter gear hanging off the front (timeing case end) of the
crank on a F***ing great taper ;-((.................
Graham
>In article <Nq2p3.9091$V21.2...@nnrp3.clara.net>, "JLE" <sca...@MAPSONfreeuk.com> writes:
>
>>Not the old Triumph 1300 FWD way of doing thing..........surely
>>not<BG>
>
>Which was what? I've never had the "pleasure" of working on one of these.
Heeee Heeeeee
They had the starter ring at the FRONT of the engine (timing chain). I
once spent nearly a full day (before I am as good as I am now !!!!!!!)
trying to get a none runner to go. Someone had fitted a "normal"
starter motor instead of the correct - reverse direction - one. The
engine was being spun backwards.
Cannot remember now but I bet it was a case of " Just driving along
mate, and it stopped"
Regards,
Graham
Visit http://www.hglmotors.co.uk
The uk.rec.cars.maintenance FAQ
http://www.motors.clara.co.uk/faq
Dave Plowman
JLE <sca...@MAPSONfreeuk.com> wrote:
> FWD (deep hub caps & diffrent wheels). this
> had a starter gear hanging off the front (timeing case end) of the
> crank on a F***ing great taper ;-((
Its real claim to fame was that you could change the clutch, with only a
couple of spanners in about 1/2 hour, all from *inside* the car. Where
have they gone wrong these days?
Also, it had an excellent turning circle for FWD, angled driveshafts or
some such.
--
Dave Plowman dave....@argonet.co.uk London SW 12
RIP Acorn
Mike Walker
> I do not have full details of this system but usually the crank sensor
> picks up pulses from the flywheel (not usually the ring gear)
> Different manufacturers use different methods but usually one of the
> pulse's is missing to indicate to the ECU the crank position. Some use
> 2 sensors, one for speed and one for position. It is fairly normal for
> the missing (or triggering) pulse to be many degrees (40+) before TDC
> allowing the ECU time to fire at the correct point. If your timing is
> way out then it could be that the flywheel has been replaced wrong,
> Some engines, for example, have 6 bolt fixing and it is possible to
> attach it 60 deg out if there is no locating dowel.
>
> a search thro back postings will find his Email address. The company
> ATP has a web site listed in the FAQ.
>
> Graham
Hi there - someone called. I have looked through our data and can only
find reference to the 924 Turbo having a conventional distributor and
ignition amplifier and a Bosch K injection system. The 944 is the only
Porsche Turbo using a starter motor ring gear type timing system (On the
earlier Bosch Motronic Systems). So unless the Bosch information is wrong ,
I can only puzzle as to what this vehicle is. I will keep searching to see
if there is any reference to a Porsche 924 Turbo with any type of programmed
ignition.
Regards
Mike http://www.atpelectronics.co.uk
JLE
Graham wrote in message <37a559d5...@news.btinternet.com>...
>On 2 Aug 1999 08:01:38 GMT, hu...@nospam.demon.co.uk (Huge) wrote:
>
>>In article <Nq2p3.9091$V21.2...@nnrp3.clara.net>, "JLE"
<sca...@MAPSONfreeuk.com> writes:
>>
>>>Not the old Triumph 1300 FWD way of doing thing..........surely
>>>not<BG>
>>
>>Which was what? I've never had the "pleasure" of working on one of
these.
>
>Heeee Heeeeee
>
>They had the starter ring at the FRONT of the engine (timing chain).
I
>once spent nearly a full day (before I am as good as I am now
!!!!!!!)
>trying to get a none runner to go. Someone had fitted a "normal"
>starter motor instead of the correct - reverse direction - one. The
>engine was being spun backwards.
>
>Cannot remember now but I bet it was a case of " Just driving along
>mate, and it stopped"
I spent about 1 &1/2 days trying to get the starter ring gear ass of
the taper once, and the garage had the right Triumph service tool ! I
think we ended up cuting the thing off...........
Chris Wilson
dave....@argonet.co.uk says...
> Its real claim to fame was that you could change the clutch, with only a
> couple of spanners in about 1/2 hour, all from *inside* the car. Where
> have they gone wrong these days?
Pah ! :-) VW K70, clutch change in 11 minutes, using only 2 tools.
From under the bonnet, no danger of getting the trim mucky :-)