Procedure for starting my '73.5 CIS after a 3 year storage?
 

Hi all,

I have a '73.5 911T Targa with the CIS fuel injection 2.4 engine. The guy I purchased it from started restoring it 3 years ago. He knew it would take awhile to restore so he drained all the fuel from the tank, lines, and CIS. I don't know how thoroughly he drained the fuel from the CIS system, but I've disconnected the lines in various places and given them a good whiff (not too much now :D )...they do not smell like old varnished gasoline.

I plan to replace all the rubber fuel lines and get a new fuel filter. Anything else the you would replace? I know the CIS is a sensitive system...is there any particular procedure I should follow before starting it for the first time?

Also, I'm not sure what to do with the fuel tank...the '73.5 has a unique plastic baffle in it, and I've heard it shouldn't be boiled. I've peered inside it, and it looks remarkable good except for a little rust on the very bottom of the tank. The rust isn't flaky or anything, I think it's just surface rust from sitting for three years without fuel in it.

Could I just slosh some rust convertor (the kind you buy in Pep Boys) in there and drain it out? I also have a can of POR15 (the metal rust preventer, not the fuel tank specific stuff) I could coat it with. Would gasoline dissolve those solutions and cause problems?

Thanks for any advice.

Fuel pump may be bad......I like to use Seafoam. Change the oil using it.

As far as the tank goes, definitely try to wash away as much of the surface rust as you can by sloshing. Also, remove the filter from the bottom of the tank and check/replace that as well. You may be able to clean it if necessary but it is very fragile. Don't know if any converter will hold up against gasoline, or if the phosphoric acid used in the POR-15 solution will keep the metal protected, but it's worth a try.

Does the car have a pop-off valve in the air box? Be very careful as one backfire from a long-sitting engine can blow that airbox to uselessness--even if it does have a valve.

One other thing you may need to prepare for is air leaks. The rubber hoses and connections for the CIS need to be absolutely leak free or you will have performance problems. Small cracks and shrinking seals can be a real headache to track down, just be aware. Ideally, replacing all rubber hoses, seals, and connections on a long stored CIS would be the way to go but that may not be practical. Get the car started and running, and take it from there.

I've had my 73.5 for 20 yrs and it used to sit a lot.

Your tank sounds like most out there and I wouldn't worry about it for now, just don't run it real low.

Be sure you have a pop-off valve in the airbox and replace those questionable lines. I have one leak and a minor fire once.

Make sure the fuel pump is working when you turn on the key. You can ensure fuel spray by lifting the plate.

Next, check that your start valve is getting current. It will only work when the lever is all the way up and the key is turned to the "starter" position.

When that's all checked out, I'd have a good battery and start it up with fresh fuel. It might take a lot of cranking, but should go. Remember, the start valve only works with the key on the start position, so it will die several times as soon as you release the starter. Normal.

Before you pull the injectors to clean, I'd drive it a few weeks with Sea Foam and then change the oil. If it still stumbles, I've cleaned my own injectors with carb cleaner and compressed air. They won't come out easily, the O-ring will be very brittle and hard.

G'luck and keep us posted.

also turn it over a few times by hand - maybe spray a light oil in thru the spark plug holes 1st

use new fuel - drain old fuel out and add it bit by bit to another car or a lawnmower, etc.

Thanks for the advice...yes, I do have a pop-off valve. I also did the marvel mystery oil in the cylinders treatment and turned it over a few times.

Bob, when you say "You can ensure fuel spray by lifting the plate", what plate are you referring to?

Air Flow Sensor Plate - Remove Air Filter and it's right there.

Your reading pleasure:

How to Tune and Modify Bosch Fuel ... - Google Books

Change the oil, install a new fuel filter. Check the fuel lines at the fuel pump and at the tank return line for cracks. Disconnect the fuel pump relay and crank it over a few times until you see the oil pressure gauge show pressure. Then reconnect the fuel pump relay and it should start.

Hi Bottlenose,

how did the reanimation go? Any surprises or learnings?

I might be in the same situation soon (although the 73.5T I am looking at hasn't been started in 10 years), so I am curious to hear how it went...

Thanks for sharing!

Wow...that was over a year ago! The car is running really well for about six months now...took me awhile to get it tuned just right. I followed the advice of the people on here and it ran great on the first try. It was hard to get started though...needed a fuel accumulator and cold start valve.

For a 10 year stored car though, I'd expect varnish in the tank and lines...and you'll want to do the Marvel Mystery oil treatment on the cylinders. You can search for that process...there's a lot of stuff you need to do before trying to restart a car stored that long.

Thanks, your feedback is appreciated.
I am really trying to figure out if it makes economic sense to pull the trigger on this car (I don't own it yet) - i know, I'll probably find out only during the process itself, and in any case a thorough PPI is key....

Anyone else who wants to chime in here - please feel free!