|
|
|
|
| Author |
|
|
Registered
Join Date: Jul 2009
Location: Williamstown, NY
Posts: 12
|
79 911sc will not start
Calling all fuel injection and electrical wizards for 79 911sc euro.
After an extensive rebuild, my car will not start. I installed an MSD6A as part of the rebuild, changed out the green dizzy signal wire, making sure to get the correct polarity, and had the dizzy overhauled and cleaned and installed a new blaster coil with magnecor plug wires.. The car would not even try to start so this is what i have done thus far: verified spark and proper function of msd6A. changed out gas with fresh tank verified compression, sat. for all cylinders. verified dizzy installed correctly and not 180 out verified cam shaft timing correct. jumpered contacts on fuel pump relay to verify operation while trying to crank the engine. I lifted the mixture control arm with ignition on and checked spray pattern and volume of all injectors which was good. Checked the plugs and they were dry; then i placed an injector into a container and tried to start the car and no fuel flowed from injector. I tried this with the fuel pump relay both installed and with jumper installed. So, the bottom line here is i am getting fuel thru the injectors when i push up the mixture control arm, but there is no flow thru the injectors when the engine is cranking. So, what on earth would cause this??? I believe the cracking pressure for the injectors is around 45psig, is it possible that i am not reaching that pressure while the engine cranks? possible problem with the fuel distributor or WUR? I also hooked up gauges to the fuel system and got 68psig for system pressure and about 50 for the cold control pressure. Hoping this question will offer all you porsche professors out there a suitable challenge. Greatly appreciate your offerings. |
||
07-03-2009, 06:51 PM
|
|
|
Designer King
Join Date: Mar 2004
Location: Toronto, ON Canada
Posts: 5,499
|
Offhand it sounds like your cold cp might be quite a bit high. How warm was it when you tested today in Williamstown, NY? 70? If so, I think the ccp should be about 35 psi, not 50.
__________________
Paul Yellow 77 Sunroof Coupe/cork interior; 3.2L SS '80 engine/10.3:1/No O2; Carrera Tensioners; 11 Blade Fan; Turbo tie rods; Bilstein B6; 28 tube Cooler; SSI, Dansk; MSD/Blaster; 16x7" Fuchs/205/50 Firestone Firehawk Indy 500s; PCA/UCR, MID9 Never leave well enough alone |
||
|
07-03-2009, 07:23 PM
|
|
|
Registered
|
Have you verifed that your plug wires are on correctly (Dizzy turns CCW on the 79's)
__________________
Pete 79 911SC RoW "Tornadoes come out of frikkin nowhere. One minute everything is all sunshine and puppies the next thing you know you've got flying cows".- Stomachmonkey |
||
|
07-03-2009, 07:32 PM
|
|
|
Registered
Join Date: Jul 2009
Location: Williamstown, NY
Posts: 12
|
it was about 65 today, so my cold control pressure should have been about 25 psig.
Good question on the plug wires. yes, that was the first thing i checked. I am a little unsure of the mechanics of why the injectors will open when I lift up the mixture control unit lever and why they do not open when I crank the engine. Is this a function of the control pressure? |
||
|
07-03-2009, 07:46 PM
|
|
1979 Porsche 911SC
