928 running rich

[flanbuild]

hello all i am a new porsche owner and new to your site i have a 79 928 with just over 10,000 miles on it when I took it out of storage it fired rite up but would not go over 2000 rpms then stalled after 5mins or so. i found a leak in the fuel accumulator replaced it and also the fuel filter. now it runs very poorly and very rich. it starts fine when cold but will die after a few mins then wont start until cold again. any ideas?

[stepson]

If it was in storage for very long, the fuel has left deposits that may be clogging your system. If it just starts for a few seconds, then dies, it's running on the cold start valve and the injectors are not providing fuel to the engine.
SOMETIMES, this can be "solved" by just being persistent in trying to start the car. Eventually the car will start and run rough. Then, as more and more new fuel passes through the system, it gradually cleans the system and the car will run smoother and smoother.
These cars do not like storage at all.

Oops, I missed the 5 minutes part. What has probably happened is that the fuel "gunk" has clogged vital parts of the fuel distributor. (Read: tiny little screen filters) The car is gonna be fuel starved until you get the fuel system cleaned out. ( Fuel distributor, fuel lines, injectors, etc.)

[19psi]

Being that it only starts when cold, runs extremely rich then dies when starting to get warm...my guess is the cold start system is NOT disengaging and it eventually floods out.

[MPDano]

CIS doesn't like to sit. You need to go through the whole fuel system and clean it out. To include all the small filter in the Fuel Distributor and WUR. How long was it in storage? Was it yours the whole time in storage? Need more info "and" pics.

[19psi]

Yeah, I'd love to see pics of a 10,000 mile 928 too!

[AirtekHVAC]

Welcome....spot on with fuel system cleaning....want pics too!

[Rupesy]

Get yourself a CIS fuel pressure tester. Relatively cheap and will tell you a whole lot about what is going on from cold start to warm up. I'm seconding the idea of the cold start system. I had a piece of that screen get stuck in the WUR diaphram and it acted just like that. Plenty of air on the start up since the Aux air valve was open, but once it closed it was way too rich. Easily found with a fuel pressure tester.

Do a google search for "bosch cis k jetronic fuel pdf" and you will find a technical instruction manual in one of the links. It is very informative of the entire system and explains the function of each component in the system. It's is only a hair different than the 928, but 95% is the same.

[flanbuild]

thanks for the help gonna try a few things will keep you posted. here are a few pics

[MPDano]

Very nice time capsule. Rid the pin stripping and that would make it perfect.

[AirtekHVAC]

I love that interior

[flanbuild]

ok here is an update i cleaned the fuel distributer and tried to shut off the cold start injector but have no clue on how to do that. i didn't see any screens to clean and the distributer looked fine no gunk at all. next step is fuel pressure gage and vacuum gage

[MPDano]

Each injector line leaving the fuel distributor to the injectors will have a small screen in there. Unless they were removed by the PO. The WUR has a small screen on the fuel inlet side of the WUR.

Your new CIS Fuel Pressure Gauge will do zero good unless you address all the fuel lines. I asked you a few question which are important to your troubleshooting of CIS. You "need" to drop the tank and clean it out. Then follow all fuel towards engine ending at the Injectors. By firing it up without doing all this, you've probably gummed up the Injectors as well.

[mikeesik]

Hello.
You have a 928 with 10000 miles ???
If you wrote that right and I read that right...that is amazing!!
WTF??
What I ask is what most I imagine want as well.
Many-many pics. of your car.
Please.
-whoops AND history.

[flanbuild]

ok so its finally on the road with a new cold start relay and an fuel distributor to the tune of $2000 thanks for all the help