rebuilding a fuel distributor

elanko · 06-29-2004, 02:38 PM

Hey all,
I posted a topic a few weeks ago-and got quite a bit of great advise-thanks.
Anyway-I just wanted to know if anyone has a thread that will instruct me in the art of fuel distributor rebuilding? the platform is a 78, 911 sc, AC, but no other toys. The fuel distributor has the following number on it (Bosch) 0438 100 077

stormcrow · stormcrow's Garage

There is a company out there that sells rebuilding kits for the unit. I believe it's performance parts. Give them a call.

Steve

"A Porsche does more then just go fast in a straight line"

Oracle · 06-29-2004, 08:42 PM

Hi,
I was looking for that exactly and sadly found that Bosch will not have any parts for sale to the public, the only option is to buy a unit from them, the good thing is that even rebuilt units (from reputable places) are factory rebuilt, the problem here are the tolerances.
Saying that.... I'll have to buy the unit for ~$1000

Check this web site for all information:
http://members.rennlist.com/jimwms/CIS/CIShome.html

Word of advise: Prior to hooking your brand new/rebuilt fuel distributor make sure you have cleaned the fuel tank perfectly, otherwise will jam it and basically break it again. In fact that happened to me, the rust was too much for the filter and jammed the piston, that sucks!

Good Luck
-J

elanko · 06-30-2004, 02:22 PM

Well Ive pulled the fuel distributor, and removed the piston. There was sand on the piston, and its been cleaned (with solvent, and compresssed air) out. Ive re-installed the f. distributor, and the car has the same problem-flooding on starting. Does anyone have any tech info on the fuel distributors? Preferably an exploded view, and details re the re-building? I do posess the tools to split the case (star drivers), and Im ok with doing it as long as I have some good tech info on the re-assembly. I have installed a new fuel filter already, and tried to start the car with the line to the control pressure regulator disconnected, and routed into a safe container-same result-flooding como loco!

klaucke · 06-30-2004, 02:35 PM

Flooding on starting could possibly be a WUR related problem or a problem with the injector on the airbox that only operates at warmup?

vash · vash's Garage

maybe leaking injectors or cold start valve?

stormcrow · stormcrow's Garage

Before you get into taking apart the fuel distributor, make sure your piston is at rest with the key in the off position.

What I mean by this is that the piston needs to be in the closed position so that when the fuel pump runs it will not allow fuel to enter the into the injector lines.

You should only have fuel going to the injectors when the sensor plate is being lifted by the air intake through the air box otherwise you could flood your engine.

Steve

"A Porsche does more then just go fast in a straight line"

elanko · 07-05-2004, 05:34 PM

Hey Noah,
Still got that fuel Distributor? My platform is a 78 sc targa-will it fit?
Thanks
Elliot

2.7RACER · 07-05-2004, 05:52 PM

I learned a little knowlege is dangerous. I discovered the mixture control adjusting screw for the fuel distributor on my '76 CIS system. It wasn't long before I was having trouble flooding the motor at startup. I had the screw set too rich, so rich that as soon as the fuel pump came on it was pumping fuel through the injectors into the motor. I finally found it by pulling one injector and placing it in a mason jar, turned on the ignition and there it was, fuel flowing through the injector. I got my little handy dandy allen tee-handle and backed up the mixture adjustment screw until the fuel flow stopped. End of flooding at startup. I hope your problem is this simple. Good Luck!

Brent 930 · 07-05-2004, 06:01 PM

Your crazy if you think you can rebuild a fuel distributor. There is a reason Porsche states not to disassemble the unit. Also no surprise you can get any of the parts or diagrams. You can send it out to Special T Auto and get it rebuilt and flow matched to spec. for $469.95 with your core. This is your best bet before you mess it up. Sorry for the harsh words but I don't want to see dig yourself a hole you can't get out of.

Brent

1980SC · 07-06-2004, 10:43 AM

I must be crazy then.

I rebuilt mine about two years ago. It's been working fine ever since.

-Rob
1980SC

gustaf · 07-06-2004, 11:52 AM

If you had sand on the piston, there are probably some grooves that are causing it to hang up. This is a very precisely machined part and the slightest imperfection will cause problems with binding.

When I rebuilt mine (Call me crazy too, but I rebuilt my FD a year ago as well and it works great!!) the first piston and cylinder I used had a small burr that made the piston catch very slightly. Once it moved from it's resting place, it would not return to rest and would flood the motor. I got a different piston and cylinder that operated very smoothly and things worked great.

William Miller · 07-06-2004, 12:56 PM

Ok, where'd you locate parts?

gustaf · 07-06-2004, 01:09 PM

I had 2 FD's and made 1 good out of the 2.

I know that there is a place in CA (Fuel Injection Corporation I think) that rebuilds FD's. You could try contacting them and seeing if they would sell you the necessary parts. There are really only a few parts to them anyway.

Brent 930 · 07-06-2004, 03:32 PM

OK, unless you have a flow bench with fuel pumps and the equipment to measure the flow rate of each port after you rebuild it (assuming you can get the parts and understand how the FD works inside...LOL) so you can flow match it then your not crazy. Otherwise if you can't do it then your only cheating yourself. If you don't have the right flow rate and flow matched ports you will in time screw your engine up. I always try to save a buck but I see alot of trash going on with peoples cars and these cars should be done right with the highest quality possible. If not then sell it to someone who will keep the integrity of the car.

KobaltBlau · 07-06-2004, 03:40 PM

Time for tbitz' megasquirt kit...

1980SC · 07-06-2004, 05:55 PM

No flow bench is needed to repair a fuel distributor. That's crap.

Fuel distributors are quite simple on the inside.

-Rob
1980SC

wm711 · 07-06-2004, 06:02 PM

im crazy also, rebuilt mine, works great. it was a 6 beer job.

wm711 · 07-06-2004, 06:06 PM

be careful when you put compressed air on it to pop out the piston, sob comes out FAST

Brent 930 · 07-06-2004, 06:16 PM

I don't doubt you rebuilt it and it works but you have no clue how each port is flowing without the right equipment. It might seem simple inside but the lower and upper chamber is tricky and how it flows fuel through each orfic.

LOL