Starts, but does not continue running...
 

Having the motor ('83' 3.0) and trans out for the past few months, I have reinstalled and reconnected all lines and electrical connectors....but, when starting the motor, it acts as if it ignites a teaspoon of fuel and then shuts down. ? *%#^ Does it sound like a 'ground' or 'vacuum' issue, or should I stay in the fuel line area ? I did replace the small black plastic OEM fuel line with standard rubber hose...!?

No major set ups changes were done. Just some light detailing and cleaning.

Any list of check points that I can run through will be appreciated.

Ric
760-249-3425
Wrightwood, Calif.

Sounds like fuel flow/pressure.

Have you checked to see if injectors are working? Pull an injector, place it in a jar, then raise the airlflow plate....

Fuel injection fuel lines.........
 

Ric,

What small black plastic OEM fuel line did you replace with standard rubber hose? Did you use a fuel injected type fuel hose? Whenever I do a start-up for a newly installed motor that has not ran for a while I checked the following:
1. Check fuel pressures (control, system and residual).
2. Pressure test for air leak/s (vacuum).
3. A fully charged battery (12.5 volts minimum).
4. Presence of ignition or sparks during cranking.

Turn the ignition switch and it should run and idle. Follow the above suggested guidelines and you'll get it running. Keep us posted.

Tony

Here's what it sounds like to me. your cold start valve is working, firing a nice shot of fuel into the intake, to get it started..............but your engine uses up that fuel and the engine dies because your fuel pump may not be working. A simple check to see if the fuel pump is working , as Chris says, is to remove the air filter and lift the air plate. Do your injectors squeal as they get pressurized? If so, your fuel pump is working. i would try this simple test 1st....sometimes, after having the engine out, the fuel lines are totally empty and need to be primed a bit to get things firing. If you find out that the fuel pump is working, the system is primed, the injectors are squealing, etc. and the car still won't continue to run.............I'd move on the system pressure tests.

Regards,
al

Thanks for the insight... I will start up front with the fuel pump today and work my way back to the motor. I will update my findings later today.

The thin OEM line that travels from the fuel accumulator to the throttle body. And now that you mention it, I didn't request a "fuel injector" type fuel hose.

I heard all kinds of squeal through the air flap and had plenty of fuel pressure. So I decided to give it another try.... and presto!! the purring of a 3.0 with the muffler off was the best sound to my ears this morning. WOW !

So, besides all the excitement, the conclusion is to prime the lines to get the blood flowing again. Thanks again Chris, Tony and Al for your dedication to making sure Porsche's are for driving and not to be garage trophy's.

Fuel line.......
 

alt77,

Is this the fuel line from the bottom of the fuel accumulator? If that's the case, that's the drain/return line that has low fuel pressure. But if for some strange reason you have a return line blockage, that return line would experience a very high fuel pressure up to 100 psi. The regular fuel line use for carburator system could swell and burst. It is better to err on the caution side than be sorry later. The decision is all yours.

Tony

Tony, that hose is the small dia. black plastic line that "T's" just before and above the throttle plate. I changed out the longer hose that attaches to the top of the accumulator via a goose neck fitting. I honestly did not want to change it out originally, but the plastic cracked and separated at the goose neck fitting. I attempted to reheat and push it on the the fitting with no success. It never cooled and shrank tightly on the fitting... that's when I decided to just replace it with standard 3/16th rubber gas hoses. I personally don't like having to clamp the hose ends...( I don't fires in the engine compartment )

After driving it around the block...I noticed that it wants to fluctuate at idle... from 200 rpm up to 1200 rpm. It may be running a little rich. Any ideas of why?