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-   -   CIS issues (http://forums.pelicanparts.com/porsche-928-technical-forum/677725-cis-issues.html)

onestar 05-13-2012 11:50 PM

CIS issues
 
i have been looking through my ignition system for awhile replaced a few things and now im back to the fuel system. i noticed while cranking i get a leak in the rear fender. i took the tire off and had a look it seems that the gas is coming from an overflow. so i looked through and i noticed that i have gas going through all the way to the injectors and the distributor but when i looked at the regulator i had no gas going to or from it. i cant tell why i have no gas at the regulator but i think that if im not getting gas all the way through there must be a blockage somewhere or something im not seeing. if anyone has any ideas on why there is no gas at the regulator and how to get it there i would appreciate the help thanks.

MPDano 05-14-2012 04:32 AM

...or your not getting enough fuel pressure. I thought you had this car running a few months back?

SeanR 05-14-2012 05:29 PM

If you have any sort of leak in the fuel system, you need to fix that first before you can even start to trouble shoot anything else.

Fix the leaks first.

onestar 05-14-2012 06:02 PM

the car was running for a little bit then it died. that`s when i did the ignition stuff. the leak i mentioned seems to me like an overflow more than a leak it only happens after i have been cranking and where its coming from it looks to be put there on purpose. i was wondering if it could be not enough pressure at the injectors, but if that was the problem wouldnt there still be fuel at the regulator

MPDano 05-14-2012 06:11 PM

Overflow goes back to the tank (inside the tank) and not on the road.

anakilat 05-14-2012 06:34 PM

Can you be more specific where the leak is coming from? Is it near the top of the fender well under the fuel filler? Is it near the front where the accumulator and/or filter is located? Is it coming from the plastic tank at the top of the fender well?

onestar 05-14-2012 07:03 PM

http://forums.pelicanparts.com/uploa...1337050843.jpg
http://forums.pelicanparts.com/uploa...1337050871.jpg
the little opening on top is where the gas is leaking that is in the upper part of the fender

AirtekHVAC 05-15-2012 03:08 AM

Isn't there supposed to be a hose connected to that? There was on mine.....

Luis_M 05-15-2012 07:43 AM

You have a bad accumulator. The diaphragm inside is leaking and fuel is finding its way out the top. Some early CIS cars had a fitting at the top of the accumulator with a hose that led back to the tank. It looks like you have the fitting, but no hose. The later CIS cars just had a small ventilation screw at the top. Hose or not, since it's leaking, you should replace it.

Luis_M 05-15-2012 08:01 AM

I assume you mean no fuel to or from the warm-up regulator, as in nothing drips out of the inlet line at the WUR if you disconnect it from the WUR and jumper the fuel pump relay.

First, make sure you don't have a hot-start valve, basically a solenoid valve sitting between the rear two intake ports on the passenger side with fuel lines going into and out of it. I doubt you have one, but it is possible someone retrofitted one at some point. I haven't heard of one on a USA model car, but it's worth a quick look. It supposed to open briefly during hot starts. If you have this valve and it is bad, it basically bypasses the WUR and send all the fuel back to the return line, for a near zero control pressure.

If you know you have fuel to the distributor and injectors, then there is either a blockage in the control pressure path inside the distributor itself or in the metal fuel line between the top of the distributor and the warm-up regulator. When you jumper the fuel pump relay, does it get harder to push down the air-flow metering plate? If not, the blockage is probably at the small restriction flow port and channel inside the distributor that connects the fuel coming in to the distributor at system pressure to the control pressure reservoir on the top of the fuel metering plunger in the center of the distributor. If this is the case, you probably need to have your distributor rebuilt. You can try blowing air or carb cleaner backwards through the top of the distributor to dislodge debris, but it could find its way back. If you do this, the control plunger will be launched down out of the distributor, so if it is out of the car, watch out.

If it does get more difficult to the push the plate down, then the blockage is between the reservoir and the WUR intake, hopefully in the fuel line, but that seems pretty unlikely.

MPDano 05-15-2012 09:21 AM

Luis is the CIS Man!! If you've seen onestars engine compartment, I am surprised his Accumulator looks as good as it does.

anakilat 05-15-2012 03:41 PM

I just re-read this thread and was wondering what the original problem was. Did the car not start? Did it run badly? Or was it just the leak that was a problem?

onestar 05-17-2012 11:41 PM

when i bought it originally it needed a fuel pump and just restoration in the cosmetics. since then ive had it running but it hasnt stayed running long enough to tune everything to keep it running. so ive went through my fuel system and ignition system replacing varius parts that went bad over the years it was sitting. now im back to something in the fuel system being the issue


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