Newbie CIS Question

911mark · 09-30-2008, 09:57 AM

I bought a '77 911 that needs lots of help. It does not start and I have located the problem is in the fuel distributer. I was going to replace it with a rebuilt one and noticed the fuels hoses to the injectors don't seem to follow and pattern. Is there a certain spot the hoses attach to the distributer? The appeared to be in the following order starting from the left of the pressure connection on the top: Cylinders 2, 1, 3, 5, 6, 4. Is this correct?
Thanks in advance.
Mark Doerr

kach22i · kach22i's Garage

There is a CIS diagram floating around you could search for, plus you can look in the Pelican Parts; parts & diagram section or look for articles in the tech articles section.

911mark · 09-30-2008, 10:58 AM

I have looked at the diagrams but it does not show what order the cylinders connect to the top of the distributer. Maybe I am missing something?

kach22i · kach22i's Garage

I have posted lots of pictures of my 1977 CIS 2.7 when I changed the alternator and back when I cleaned the engine. However that darn airbox seems to be in the way every time.

Just keep doing searches or looking in your books. I'll try to post pictures of my engine in about four hours with the airbox off.

Maybe an airbox removal or engine pull thread will show what you seek.

kach22i · kach22i's Garage

Oh, oh...I checked this twice.

2, 3, 6, 5, 4, 1 counterclockwise from that middle thingy.

How loose are those connections supposed to be as they go into the top of the engine? I have a few with lots of wiggle.

911mark · 09-30-2008, 12:06 PM

Mine are totally different. I am wondering if because the system is Continuous Injection System it does not matter where the hoses are connected. The injections are controlled by the engine and the valves. When the engine's valve opens for the fuel, the pressure is relieved at the injector and the others wait. This may explain why there is no definite answer as to what order the hoses are connected.
As for question about the banjo connections at the top of the fuel distributor, mine are tight. There are washers on top and bottom of the connections.
Mark

1982911SCTarga · 09-30-2008, 12:42 PM

The fuel distributor doesn't care how you hook up the individual lines to each fuel injector.

Brian

Jim Sims · 09-30-2008, 03:32 PM

Have you done troubleshooting with a CIS pressure gage harness following the procedures in one of the CIS manuals? If not, pause and do this as troubleshooting a CIS system by replacing parts can be very, very expensive and frustrating. Order doesn't matter as long as the lines reach the injectors.
Good luck.

boyt911sc · boyt911sc's Garage

Mark,

What particular problem have you discovered in your FD? Have you used a CIS fuel guage in your troubleshooting? Your discovery and other information may help others in the future. Thanks.

Tony

T77911S · 10-01-2008, 03:47 AM

+1 on does not matter where they are connected. honnect for easiest path to injectors.

+1 on why the fuel dist? big expesnse. i suspected mine was bad for a while, turned out to be something else.

911mark · 10-01-2008, 05:27 AM

My main concern is that I am getting gas to the FD and not past it. All of the banjo connectors show no evidence of gas and the pressure valve on top has loads of pressure. Where do I get a CIS pressure guage and what type? And exactly what does it do?
Mark

ossiblue · 10-01-2008, 06:17 AM

Quote:

Originally Posted by 911mark

My main concern is that I am getting gas to the FD and not past it. All of the banjo connectors show no evidence of gas and the pressure valve on top has loads of pressure. Where do I get a CIS pressure guage and what type? And exactly what does it do?
Mark

Google CIS pressure gauge, or do a search on this forum as there have been several requests like yours with responses. I do recall that J.C. Whitney offers a gauge, for example.

As to what it does, the gauge set up will measure the fuel pressure in your system from the fuel pump, also from the fuel distributor to the Warm Up Regulator (critical component), also through the WUR for the entire system--closed loop. It will measure the pressures cold and warm, regulated and unregulated--all of which must be in specs for your engine if it is to run properly. Typically, measuring the fuel pressures is the starting point for CIS problems. Do a search on CIS and get a good background on how it works. It's a necessary read for anyone who owns a CIS car.

Finally, ditto to all who question your conclusion that your distributor is the problem. It very well may be, but you should check the system first as the distributor is a costly part to fix (especially if it is not the problem), and other parts of the system are more typically at fault.

Keep us up to date. Lots of help here!

T77911S · 10-01-2008, 08:42 AM

on CIS, the injectors spray continuously as long as the key is on and the the plate in the air flow meter(AFM) is raised. pull an injector, turn the key on and push up on the plate in the AFM.
CIS is very sensitive to air leaks.
have you verified it has spark

MatthewBrum · 10-01-2008, 10:02 AM

Quote:

My main concern is that I am getting gas to the FD and not past it. All of the banjo connectors show no evidence of gas and the pressure valve on top has loads of pressure. Where do I get a CIS pressure guage and what type? And exactly what does it do?
Mark

Did you check if the plunger is stuck? The air vane lifts the plunger and that allows fuel to flow to the injectors. Try lifting the plate with the fuel pump on and see if the injectors squirt.

911mark · 10-01-2008, 11:18 AM

I haven't tried to lift the plate and see if the injectors are working. I will try that and see. Also is there a pressure valve of some sort on the side of the FD that is accessable after unscrewing a cap? I have looked at the diagrams for the FD and it shows a screwed cap on the side that has a valve, spring and o-rings. Could this be stuck? The car has sat for at least one year before I tried to resurrect it. I am trying obtain a CIS pressure test kit from a fellow PCA member. This should give me information whether I am getting pressure.
Mark

911mark · 10-01-2008, 11:24 AM

Ok another question. How do the injectors come out. Do they unscrew or are they held by a O ring and you pull them out?
Mark

kach22i · kach22i's Garage

Quote:

Originally Posted by 911mark

Ok another question. How do the injectors come out. Do they unscrew or are they held by a O ring and you pull them out?
Mark

I just want to know how to tighten them, if it's ain't broke don't fix it comes to mind.

lucittm · lucittm's Garage

On the diagram that kach22i posted, the injectors are part #21 and the o-rings that seal them and hold them in place are part #22. Most likely they have become as hard as a rock due to heat if they have not been changed out in the last few years.

Buy six new o-rings.

There is a tool you can buy to lever the injectors out, or you can use the two wrench method. Remove the fuel line going to the injector and place an open end wrench under the hex portion of the injector. Use another wrench as a fulcrum and lift the injector out at an angle. Try to keep the big pieces of broken o-ring from falling back into the intake manifold.

The newer turbo injectors screw into the intake manifolds with an aluminum sealing ring.

Mark