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-   -   engine starting problem (http://forums.pelicanparts.com/porsche-911-technical-forum/650884-engine-starting-problem.html)

DohertyCM 01-14-2012 05:03 PM

engine starting problem
 
I cant seem to start my car. :(

I have spark, and I have gas, infact it seems as though i flood the car when i try to start it.

The fuel injectors spray fuel when the ignition switch is turned on.

Its a solid state ignition with an MSD box, and with the spark i dont think that is a problem.

However I do have one question. On the CIS pressure plate, if you press up on it should there be any resistance. Because when I press up on it it there is no resistance. it freely moves. I ask this because I am at a loss....

ossiblue 01-14-2012 05:20 PM

I think you've found your problem. Yes, there should be resistance when you push up on the plunger. In addition, no fuel should spray from the injectors until that plunger is moved up. Since your plunger moves freely and the injectors are flooding the cylinders, it sounds like the lever/pin in the fuel distributor is stuck in the open position (wish I had a diagram to post, but someone will post how to access and clean/free the mechanism, shortly, I'm sure.)

Meanwhile, don't try to start your car! Free flowing fuel will cause hydro-lock in the cylinders and you will have more serious problems to deal with. Even if the problem is not the plunger/lever/pin, the issue of importance is flowing injectors with the turning on of the ignition--you have a 74 and the pump comes on immediately.

DohertyCM 01-14-2012 05:25 PM

Holy Crap...
 
I am glad you told me this!

HOW DO I FIX THIS!!?

boyt911sc 01-14-2012 06:45 PM

FD plunger........
 
The only way fuel is delivered to the CIS injectors, is that the FD plunger has moved up opening the slit/s. Or the fuel mixture screw has been turned overly rich setting the plunger at open position. Or the plunger does not drop freely to its rest position and is stuck open.

Did someone tinker the fuel mixture screw recently?

Tony

DohertyCM 01-14-2012 07:06 PM

No
 
Has not been messed with.

Since the last post I have disassembled the distributor. and the plunger was stuck in the up position.

the insides look clean. I am surprised not to find a spring to push the plunger back down.

I guess the only thing I can do is clean the plunder and put it all back together.

Also the diaphram listed in other threads is some type of film. the only diaphram in mine is a thin metal sheet. But no damage.

boyt911sc 01-14-2012 07:29 PM

No spring....control fuel pressure does the work.....
 
Quote:

Originally Posted by DohertyCM (Post 6494410)
Has not been messed with.

Since the last post I have disassembled the distributor. and the plunger was stuck in the up position.

the insides look clean. I am surprised not to find a spring to push the plunger back down.

I guess the only thing I can do is clean the plunder and put it all back together.

Also the diaphram listed in other threads is some type of film. the only diaphram in mine is a thin metal sheet. But no damage.


Doherty,

The FD plunger is raised up by the air plate lever (arm). The control fuel pressure is the acting force (resistance) working against the plunger to keep it from bouncing up and down during operation. There is no spring any where inside the FD.

Tony

DohertyCM 01-14-2012 09:51 PM

Well...
 
Well, I guess I am ordering a new one then, I took it off cleaned it and the plundger moves freely but the the thing leaks now. And i hated getting that back together.

thanks for the insight guys...Time to spend some money.:mad:

DohertyCM 01-17-2012 08:21 AM

OK...some lessons learned
 
Lessons learned from this experience.

#1 . Be careful with starting the car WHEN IT WONT START!.....

#2 . Never disassemble a fuel distributor!...ITS NOT WORTH THE RISK, because even if you do find the problem and fix it, chances are the O rings inside are old and will stretch which translates into it will leak if you get it back together. And it will probably leak around the split line once its back together....leave it to the professionals with the proper tooling.

#3 Once you get everything back together, remove spark plugs disable the ignition system and motor the engine over...disable the fuel pump if able.
This is about getting the fuel out of the cylinders to prevent hydrolock.

#4 Last thing...before you start the car after its all back together.....roll it OUTSIDE and start....Gas will come out the tail pipe.

Thanks for your help guys.!


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