I hope that I went closer to my problem with rough idle/bad throttle response. After changing, ignition coil, IC module, O2-sensors, IAC Valve I noticed that on cylinder 1 there's no spark for a few seconds, then spark again, then no spark ..... I didn't notice this phenomen on the other cylinder. I think it's a problem of the optispark unit / distributor. Next saturday I could deinstall the optispark. Any tipps before?
How to disassemble the dampener, any trick to do this without a special tool (the screws are off)?
Anybody who had the same problem?
Are there new sealings / gaskets for the assembling? (I read something like an O-ring for the water pump)

Thanks for any tipps!

PS There are no dtc's on the ECU

 

The opti is still a distributor, the cap and rotor are wear items just like any other distributor, judging by your location getting parts may be a bit of a hassle but I suggest you look at getting a new cap and rotor for it when you take it apart.
No seals or anything like that but the torx fasteners you may not have the proper tools for. If you get the MSD cap and rotor kit it comes with a crude but functional tool for removing the cap screws and new phillips head screws to replace them. The rotor is I think a plain old T-9 easy to find but not many people have them till they need it for this. Again the MSD kit replaces these with philips or more recently I have heard they switched to allen head.

 

The engine has only ~45 tmls so it's hard to believe that this is a question of wear. But I tested the spark with a separate spark plug and you could see that sometimes there is no spark for 2-3 seconds. Using a new wire was still the same thing. I think if I had used my crane ignition system which isn't installed yet, there was no spark lost. Perhaps because of the sronger current flow or the multiple sparking?
I installed MSD ignition wires 3 years ago. Could these wires with a low resistance cause the problem?

 

Is it a vented or unvented opti?
If an unvented then I would strongly suspect a 45K cap and rotor.
I am not saying the whole opti just the parts that have to endure the arcing current.

 

It's a 92'Corvette LT 1. So it's the unvented system.

I know that there could be trouble with with the burned rests of the distributor which cover the inside of the housing. So is only cleaning necessary or I have to buy a cap and rotor?
Here in Germany the parts cost ~400$!

 

If that's 45k miles your belief system needs re-evaluation. 15 or 30k is a usual replacement interval for a distributor cap&rotor. At 45k I'd expect to see substantial wear.

Replacing only the cap and rotor on a 16 year old unvented opti is false economy. Get a new aftermarket opti that upgrades it to vented.

 

I believe the MSD cap and rotor for the "unvented" opti upgrade it to vented.

In practical application I do not believe there is a truely upgraded opti out there, the vast majority of us are very well served with the stock base and MSD cap and rotor kit.

 

Check the wire towers on the Opti for corrosion - particularly the connection for plug wire #1.

 

Night rider where in Germany are you located? GK autotele can get an opti in 2 days.

 

Hello!
@ZBLKHELLRZR
I'm living in the near of Stuttgart. I contacted GK but without full success. Perhaps I have to order the parts right in the USA. But then they are 25% more expensive + shipping costs. Only one store has cap and rotor separately! => ~400 $

@Injuneer
No corrosion visible. Tomorrow I want to pull the dampener, then I will have full access.

@steve9899
It's not a question of economy it's a question of necessity.
I'm repairing my vehicles for over 20 years by myself and never had to change a distributor cap before ~70k.

@96capricemgr
Is there a direct replacement cap and rotor for the 92' Corvette engine / distributor unit? I only found the whole unit for over 500 bucks.

Thanks for any further tipps!

 

Hello!
Now everthing is disassembled.
Oh god=> All parts inside the distributor housing are corroded.
The contacts of the spark plug wires, rotor => This should be no problem to clean. But the sheet metal parts behind the black plastic are strongly corroded and you can't pull the one behind the stamped round sheet metal for the ignition signals. So I will try my best to clean everything and plate the sheet metal parts with nickel (I'm engineer for surface technology).
I try to pull the sensor for the ignition signal but it's not possible.

 

Talk about an excercise in futility. You should replace the entire unit.

If cost is and issue either buy it here and have it shipped there or have one of us buy it and I can ship it to you via UPS.