Resurecting CIS from a 6-7 year sleep??
 

The fuel tank looks to be clean. I am proceeding with draining and cleaning it before attempting to start the car.
Is there any cleaner I can push through the new lines/filters to avoid having to remove and have the FD/ injectors cleaned??? Something like a 1/10 to 1/20 mix of 44K cleaner to gas - then, let it flush/recycle through the system??
Or, am I just being paranoid/OCD
Or is it likely fouled and I should just Pull the parts and have them professionally gone through.
What might the cost be to have someone like Ben at M&K clean and test the parts?

I am trying to hold down the resurrection costs because I can see $10 K going into the 915 box and I really want to move to Al's PMO/MS3 EFI, which is going to put a massive dent in my social security checks.
About 7 years ago, the block thermostat popped up out of the block at 6k rpm and dumped 8-10 quarts all over the back of the car, so I stripped it to the long block and replaced the harness, rubber lines, hoses, senders and clutch, fuel and air filters, so that stuff ought to still be good.

Dazed and confused,
chris

(single family 74 coupe)

Sea Foam is what my old school air cooled wrench uses as a initial step for CIS issues

I ran Sea Foam through 2 tanks of gas and more than a few Italian tune ups. See if it runs before you go and rebuild it.

+1 for Seafoam.

I picked up my '75 911 in 2010 and it hadn't been started for about 10 years. Inside of the gas tank was remarkably clean but only had a couple gallons of old fuel in it (PO thought his cousin had used Stabil before parking it). I drained the old gas, put in 1.5 gallons of fresh gas and a whole can of Seafoam.

I pulled the injectors from the sleeves and ran the fuel pump for a couple minutes and then let it sit for a couple of hours. I ran the fuel pump for a minute and let it sit another couple hours and repeated for about 2 days. Finally I found I could lift the plate connected to the fuel distributor. Running the pump again I got the injectors to spray. I repeated the spray/sit routine for another day and they all started spraying OK (not great). Turned out to be good enough to get the motor to run.

I did drain the fuel and swap fuel filters after that. The old filter was full of guck and the fuel had changed color...

This was all before a proper engine and fuel system rebuild.

I had a spare SC engine sitting around in the shed for about ten years. My mechanic swapped it in, got the oil pressure up, then fired it up. No problems at all.

Following.


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cis back to life
 

I have always used the BG 44K for regular fuel service every few months but never tried it as a straight cleaner.I like the method mentioned of injector lift out and purge the system until the spray pattern looks ok.I usually would change the fuel filter and clean the accumulator,warm up regulator and fuel distributor with injectors in an ultrasonic cleaner.Not expensive and you can not believe the crap that floats to the top.Also there are very fine plastic filters for each cylinder in the fuel distributor that can disrupt flow to the injectors.Do it once and do it right.Chasing gremlins from varnish can be a PITA.Fred

CIS start up...........
 

Chris,

Make sure that you have a clean gas tank free of debris and rust, clean tank filter, and fresh fuel. You could use fuel additives to help clean the system. Fresh gasoline is more than sufficient for your start up. Is there a problem you have now? You are making a simple situation too complicated. An in-line fuel filter before the FP is not needed. There are fuel filters before and after the fuel pump that do the job well.

However, if it would make you feel better adding extra fuel filter go ahead. This is your car and you could do whatever you desire. Test run the pump with fuel injectors in individual containers to collect the spent fuel. Stay safe. Keep us posted.

Tony