77 911s no start

[MrAwesome]

Hey there guys and gals. I have a 1977 911s that has been sitting for a few years (5-10years) not sure as to how long exactly. The reason I am posting today is that I can not get this thing to stay running.

So far this what i know/have done:
-got a rebuilt distributor
-checked compression 75-100psi
-tested the csi to the best of my know how
-replaced fuel pump
-I do have fuel to the distributor but very little at injectors
-when I start it it runs for about 5 seconds and dies. It seems to me like its only running on the cold start injector.
-I do have spark


Thats all I can think of right now. This is my first 911 and I am enjoying the learning experience but I am stumped!

Anything you can think of will help. Thank you in advance.

[Porchcar guy]

Did you drain the tank and flush the fuel lines out ? New battery , plugs, wires, coil would be needed too. Good Luck, you will get it !

[MrAwesome]

I drained and refilled the tank twice. Second time fuel came clean. I am getting ''clean" fuel at the distributor. I have not replaced the wires due to the fact that I am getting spark at all of them. i have replced the battery, cap, and the rotor. I did not flush the fuel lines.

[Porchcar guy]

You can also check the injectors to see if they are getting fuel ata standard flow rate and a good flow pattern...check toe archives for the way to test the injectors.

[MrAwesome]

i will do that but it dosnt seem to have enough fuel pressure to the injectors. Is there a bleed procedure for the distributor?

[Targalid]

Remove air filter, with key on, lift air meter control arm found at the back of the interior of the air box behind where the filter sits. You should hear the fuel pump begin to fill the injector lines. On a 77 there is a switch which shuts off the fuel pump except when the engine start sequence is activated. Lifting the control arm overcomes this safety feature. Lift the arm until you hear the injectors squeal. You have allowed the fuel pump to push fuel to the injectors and they are active. Stop immediately when you hear the squeal so you do not inject too much fuel into the intake manifold. This procedure removes air from the system and gets fuel to the injectors. If all else is well, your car should start at this point.

[T77911S]

per above.
the plunger in the FD gets stuck.
this would be a good time to go ahead and pull all 6 injectors, place them in jars and do a flow test. do it several times to flush the FD.

you should feel resistance as soon as you lift the plate. there should no free play as long as the FP is on.

that compression is low. check it again after you get things sorted and do a leak down test too.

[Targalid]

Ooooops! T77911S is right. That compression is low. It should be more like 175 lbs. I misread that as your fuel pressure when I saw your original post. Check the compression again. If it is that low I would not expect your engine to run. If you do a leakdown test you can find whether you have low compression because of rings, valves or some other problem. Hopefully your valves are out of adjustment and you do not need an engine rebuild. Good luck!

[MrAwesome]

The compression is 75-100psi I do not have a leakdow tester at my disposial at this time but will get one soon.

The thing that is throwing me for a loop is the fact that it will run for a short amout of time (5 seconds or so) but will not continue to run. Its almost like its starting on starter fluid, it starts for a second revs to 2000rpm and dies.

T77911S this is the first time I have had to mess with it since my last post. I am going to try your bleed idea. I will let keep yall posted.

[3stewartS]

Awesome, been there done that. Got it worked out solely with information found here, with multiple searches. My best advice would be to get a fuel pressure gauge (you will need it). The are tiny screens within the fuel distributor and I believe there's one in the control pressure regulator (aka wur), be sure those are clear.
It really is a simple fuel injection system after you understand it. Don't give up! It is worth the effort!

[manbridge 74]

Can you keep it running by manually lifting(slightly) sensor arm while someone starts car?

[steves31]

Yep need to know your fuel pressure at the wur and injectors going thru the same thing right now. Waiting for my fuel pressure gauge to get going on the repairs

[Targalid]

Inexpensive high quality leakdown tester: ATS DIFFERENTIAL CYLINDER PRESSURE TESTER (18MM) from Aircraft Spruce

CIS manual: CIS Primer for the Porsche 911
Bosch K-Jetronic Fuel Injection Manual

Trouble shooting CIS: How to Tune and Modify Bosch Fuel Injection - Ben Watson - Google Books

[MrAwesome]

I cant keep it running with the throttle or by pushing the plunger inside the air box up.

I am working on it now and cant seem to get the injector out of the intake manifold..... Is there a trick that I am missing? I have the lines off or the injectors but cant get the injector its self out of the mani.

I have good pressure going into the FD (I will get an actual number soon my battery just died so I need another one) and also returning out of the FD.

I have a PERMA-TUNE CIS. I went to there web site and got the diag info on it and it did test good.

Remember that I do have a rebuilt FD and that I cleaned out all the lines from the FD to the injectors.

Thanks guys for all the advice and help it is greatly appriciated.

[Porchcar guy]

If I am not mistaken, the injector fits in a sleeve/collar and needs to be massaged to get them out..Others will chime in who have more knowledge !

[MrAwesome]

It looks to me like they are pressed in or have a little piece of the manifold that holds them in.....

[timmy2]

If they are the same as my '78 then you just have to get a good grip on them and pull. They are held in place by an o-ring only. Probably a completely dried out very stiff O-ring, but really it's just a big fat o-ring... Use a block of wood and a wrench that will fit below the hex nut portion where the line attaches and pry them out. I have new o-rings now and they are very easy to remove compared to the first time I pulled them.

[boyt911sc]

Originally Posted by steves31

Yep need to know your fuel pressure at the wur and injectors going thru the same thing right now. Waiting for my fuel pressure gauge to get going on the repairs

First and foremost, a fuel pressure gauge is a mandatory tool for fuel injection system troubleshooting regardless which system you have. Without knowing the status of the fuel system, you'll be doing a lot of guess work in the first place. If I were to do the investigation I would check the following:
1). Fuel pressures (system, control, and residual). Condition of the WUR will tell you if the control pressure is close to spec. No need to run the engine just the FP.
2). Ignition check. Use an inductive timing light to see if you have ignition spark.
3). Vacuum/air test. While this is probably the easiest and most ignored test, some don't realize how critical and sensitive CIS for vacuum/air leak. This is the Achilles heel of CIS (K-Jetronic).
4). Check injection spray patterns of fuel injectors.





Tony

[boyt911sc]

Run the fuel pump for 5 to 10 minutes to clean and rinse the FD specially for an engine that has not run for a while. Test all six fuel injectors for flow pattern and drip. Leaking injector/s should be replaced.


Tony

[MrAwesome]

I got to work on it a little last night and will be working on it on and off today.

Last night I tried what Targalid said to try by pushing up the plunger and turning on the key until I herd the injectors squeel. I dd this and still same issue It runs for about 5 seconds.

I also drained the tank again and put 5 gallons of good fuel in.

I hooked up my fuel pressure guage to the WUR and am getting just over 100 psi. I dont know if that is correct or not....

My plan today is to pull the injectors and see what they are actually doing. Is there anywhere else that I should check my fuel pressuer?

Tony I have tested spark with a spark tester and also with the plug grounded on both sides of the engine.

Thanks again guys!!!