91 Motronic variable valve timing blues

[benny_terry]

Hello All! On my 1991 Spider I have a small problem - occasionally the engine will just begin running rich. I checked the oxygen sensor, OK - changed the plugs to platinum+2, just changed the air filter, cleaned the idle air valve... etc.
Essentially, the one thing that I can come up with is the VVT solenoid. I recently remanufactured my own "retention gasket" and could not find any information on the spacing of the solenoid to the cam actuator. I screwed it in pretty far - can anyone tell me (aside from buying the tool) how I should know how far to screw the actuator in?

Thanks, Ben

[TS Dude]

I saw this one on another forum some time ago for the twin spark solenoid/variator and it worked a treat for me, hope it helps -

I know the Variable Valve Timing system on the Twin Spark has been
discussed at length on the site, but I thought I'd share a little tip
given to me by Paul at Alfa Aid in the UK, regarding the adjustment of
the gap between the solenoid and actuator.
Without the engine running, loosen the VVT solenoid lock nut. Attach a
test lamp to the positive terminal of the battery and hold the other
end against the metal body of the solenoid. If the test lamp lights up,
the solenoid is already making contact with the actuator. If it doesn't
light up, there is a gap between the two. (The circuit has only one
route because the solenoid is suspended in an insulating material).
Either screw the solenoid in or out (depending on the above) until
contact is just made then back it off until the lamp just goes out.
Hold the solenoid firmly in position and secure lock nut.
I know the manual talks of using a feeler gauge to to measure this
distance, but apparently it's not that critical unless it's wildly out
of adjustment. Saves taking the cam cover off too.

[benny_terry]

Sounds good, I will try that!

Thanks a million.

Ben