# Rebuilding CIS after sitting with bad gas



## toastworks (Jun 2, 2000)

I can find lots of information on how to tune and troubleshoot problems with regularly running cars, but I'm into a project that hasn't ran in years.

I have a '79 Scirocco in my shop and have been replacing every bit of the fuel system I can find.

I live in Texas, where there are far less parts cars and salvage yards than I was used to in my past life up in the north east. I've been mixing and matching parts to try and get her running again, and I truly don't know if I'm making a mess of things.

Upon getting the car, the fuel system was totally gummed up and the tank was full of varnish.

A short list of what I've done so far:

-Dropped fuel tank, had it cleaned
-Replaced fuel accumulator with NOS Bosch unit designed for Porsche CIS
-Replaced rear fuel lines with brand new kit from mk1autohaus
-Replaced vent lines to gravity valve (original gravity valve remains)
-Replaced locked up fuel pump with a used Bosch (known good, and it makes 70psi out of the pump)
-Cleaned out hard lines to engine compartment with B12 Chemtool
-New fuel filter
-Replaced fuel distributor and air plate housing with one from an 8v Golf (EV), but it was missing its differential pressure regulator, so I used one that came with my Scirocco
-Replaced control pressure regulator with one off eBay that looked pretty clean
-Replaced leaky 5th injector line and verified 5th injector opens with voltage applied
-Replaced braided lines to and from CPR
-Thermo-time switch may be bad -- according to the Bentley test procedure
-Replaced flex air boot by throttle body (had a sizable hole)
-Fixed every other vaccum leak I could find

I have a K-Jet fuel pressure test gauge coming in next week along with a timing light so I can verify correct timing.

Currently it will crank, and will chug (bad timing? bad coil?) - https://www.youtube.com/watch?v=7SpsLv2jEi0

Have I overlooked anything obvious, or is my mixing and matching parts a nightmare?


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## Butcher (Jan 31, 2001)

The ignition timing is off. 

The spark is occurring too early so the piston is trying to compress the combustion.


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## toastworks (Jun 2, 2000)

Thanks Butcher! The timing was very very off.


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