alex_cristocea

Hi Folks,
I am in need of advise. A friend of mine asked me to help him fix his 911s.
The car it's an 1977 911S, US model without oxygen sensor. Last few years the car ran fine than it started to run poor when on idle when hot and after few days he didn't start at all. After that someone tried to fix it tuning the CIS with no success and then it towed the car to me.
Now I didn't worked on 911 before so my experience with this it's zero. First thing I saw was that the engine compartment electrical wiring was a mess, the spark was very weak and the engine has some oil leaks.
After checking some components I find that the CDi Box it's from an 83 240 Volvo and has the following p/n 0 227 100 018 BOSCH, the ignition coil it's from an Opel Ascona 87 I think.
The CIS system has a 4.9 BAR system pressure and a 3.2 BAR WUR regulated pressure (with vacuum).The cold start valve starts once the engine it's cranked and runs for more than 20 sec. So I replaced it with a faulty one that does not run at all to avoid fouling the engine until we will recive a good one.
We ordered an Permatune 911902 CDI box from ebay, I wired independently(A ign coil 15+, B power from ign switch(i dont't know if this has to be run by the resistor installed on the relay box) , C braker points, D ground( relay box ground and ign coil 1- gnd). Changed distributor braker points, rotor, and distributor cap, checked and labeled ign wires, changed spark plugs.
I pulled the distributor and checked that 1 it's on ign stroke and 4 it's on overlap and adjusted with a strobe light without vacuum 5 degrees ATDC. Changed Oil 20w50 Valvoline VR1 Racing and filter.
Now the car starts and runs rough on idle and if I try to apply throttle it misfires on exhaust and pops misfires on intake also.




Before

















electrical harness with insulation removed

At this point I don't know if it's a timing problem or a CIS related problem




Permatune 911902



At this time I don't know if it's a timing problem or a CIS related problem.
Should I check if the camshafts are timed correctly and how can I do that? Or coult be something else?

alex_cristocea

and the video

CarPartsDiscount.com

I am sure it could be a few things but that seems like a timing issue to me.....

theiceman

That airbox looks cracked to me letting in all kinds of unmetered air , running lean and backfiring. It may have been the airbox cover but i dont think so .. check that plastic intake manifold and look for cracks ..

also i think the 77 is a points car , im not sure how the permadoom comes in and if the points have been upgraded to a more modern system but if the points are still in that car those have to be checked and gapped properly of course. Also i am sure it will have condensors if it has points so make sure this is plaugged in and working.


oh and I would not be surprised if all the head studs are pulled out on that car. Looks like a very old 2.7 with no upgrades, it even has the old 5 blade fan.