fritz k.

No, that's not what I wanted to say. Only, that full load timing is just one point that is different. Others are the signals for engine and charge air temperature and of course the maping and surley the degree of maximum ignition advance.

​​​​​​Fritz

peterpullin

you are all right. if this part were perfect anyone would use it for a hand full of bucks instead of buying used items for thousands of dollars.
all i wanted to say is: it works for a wile until you can source a 965 part. it will not kill your engine while driving through some canyons - would not drive it to the limit with this.

there is apart to move the ignition foreward. fvd offers this. early ignition needs better fuel and should be limited. gets you 20 or more hp. so if you want to race some vettes you should not use this unit without digging deeper. my car was more alive with this - so may be this curve is more advanced.

fritz k.

Yepp, I know the brackets for the rpm sensor, which move it slightly towards more ignition advance.

It may be that the Porsche engineers were to conservative when designing it, but I think it's a dangerous game. A few degrees more or less ignition advance makes the difference between top performance and major engine damage. It should also be seen that our engines have no knock control.

And in order to survive against current vettes you should use a Hellcat anyway, should'nt you?

Cheers, Fritz

Black_Hat

Porsche was conservative with ignition advance on the C2 Turbo due to the terrible timing resolution caused the the 3 non-symmetric teeth on the stock flywheel.

put a timing light on a C2 Turbo and run it through the RPM range- the timing visibly jumps around.

Gas with ethanol is another issue to be concerned with and advancing the timing becomes even more of a possible issue.

the FVD advance device might be OK for street short burst but extended track or AutoBahn is just asking for trouble.

Stefan

wicks

GLAUBITZ says no they cannot modify an MBZ unit to match a 965 unit. I have a very good condition MBZ unit now ($100) and will try in the car this afternoon.

wicks

Update: engine runs with the MBZ unit - but idle about 700 RPM too high (air screw to reduce), engine runs very differently, feels like a sharper advance for sure, sounds different...definitely would not run her hard like this. But fine for emergency / limp home mode.

bweSteve

for a novice like myself when it comes to the EZ69,... if I were to break down on the road, what would be the symptoms I might want to have on my roadside checklist, such that it would then prompt me to then pull out-&-try this MBz unit as a backup limp-home mode device?

Of course if I'm broke down on the side of the road, I'm liable to try anything to get er running, before I call the tow truck... but a checklist might be good to have....

TIA
subscribed

wicks

Haha. The symptom was: under load 4th gear, turbo spun up, engine fully cut out with lots warning lights on dash. As if the key were switched off (normal to zero spark immediately).

peterpullin

great to hear! that was my idea in posting this „solution“

yes, it seems to be more agressive. harder idle, sometimes hard warm start in my car.
but a nice backup for the glovebox. all our ez69 will die a day. i have a spare - stored cold and dark.
no option to leave it in car for the moment you need it.

bweSteve

Is Porsche Classic doing anything about this? ... sry if that question has been asked before

peterpullin

if porsche does it would be no real solution. last price for the part was close to 7000$ - so the replacement will be skyrocking...

Megatron-UK

Is there no retrofit option that can be driven from another crank/camshaft speed derived source like the distributor, so as not to rely on the (by all accounts horrible) precision of the flywheel? Like a plug-and-play distributor with a vac/boost sensor?

fritz k.

I don't know of a plug-and-play solution, but there are some suppliers of useful freely programmable control units such as e.g. LINK ECU or ECUMaster. In the simplest version, they can do much more than is needed for an EZ69 replacement and they also have base maps with usable ignition advance curves. The accuracy problem that may exist should be solvable with a modern TDC sensor and the existing flywheel.

The programmable ECUs are also available for around $1000, but nobody is making the necessary adaptions to sensors, wiring harnesses and engine-specific adjustments because there is just no existing market.

Even if some have different experiences here: The Bosch EZ ignition control units do not die in rows as one might think.

Fritz

911 2

Would it be a good idea to repaste the heat conducting paste considering its nearly 30 years old as I believe they also die from over heating

peterpullin

defintly renew this heat conducting paste. there is much more efective material out there today. you can find it for pc cooling blocks.