84 928s running rich

[Hkp7]

I have an 84 Porshce 928s, unmodified which has a very rich fuel smell from the exhaust and I have been told black smoke has blown out the exhaust when I pass them. The car does not seem to be very responsive and actually seems to have little power during city driving. I had an exhaust leak which was before the O2 sensor which I repaired thinking oxygen was being sucked past sensor telling the computer to richen up the fuel. Still rich I noticed my fuel pressure regulator makes a medium loud clicking sound while engine is running. I ordered a new fuel pressure regulator and the parts store called me this morning and told me it wouldnt be in till monday. I have not checked fuel pressure yet. I wanted to use this car this weekend and am looking for a quick fix. Wondering what fuel pressure this car should be running at, wondering if the fuel pressure regulator would normally make a clicking sound and wondering about the cold start valve I have been reading about possibly be stuck on. I figure while I am stuck at work and cant get to the car till this afternoon to try to figure it all out, Id ask some of you guys what you think. The car has 124000 miles on it, stock cat, smog pump, basically everything stock. Any hints or tips before I get into it will be appreciated.
Bill.

[Danglerb]

With a good stock cat if the car was running rich the cat would be glowing red burning it off, so fair guess the cat is fried.

Most common reason they run rich is a bad temperature sensor, so it thinks the engine or intake air is cooler than it really is.

Pull the vacuum line on the fuel regulator and see if it smells like gas, leaking is the most common failure for the regulators. I would not replace one without checking for leaks and measuring the fuel pressure first.

Clicking might be the injectors, you can listen to them with a rubber hose or a screwdriver.

[Hkp7]

Thanks for your responce and your tips. I looked over the car yesterday afternoon. I pulled the vaccuum line from the fuel pressure regulator and found no vaccuum. I checked the fuel pressure which the book says 2.5 bar which would be around 37 pounds and noticed the needle jumping quickly from 37 to 40.
Realizing no vacuum and the regulator doing nothing, I found the vacuum leak behind the throttle body at a Y connector which had a tear in it. The leak was not audible unless I got close. repaired the connection, test drove and noticed a big difference. I bought this car around two months ago and am just now getting into the running aspect of it so it ran poorly since day one. I agree with you about the cat needing replacement. I found I still have a leak at the cat before the O2 sensor. Now it is time to figure out if I want to spend 500.00 for a factory fit cat, have a muffler shop install a high flow universal, or get into some horsepower upgrades by getting a Y pipe which eliminates cat. I guess that is a decision on whether I want to keep the car completly stock or go ahead and move it up. Thanks for your reply.

[MPDano]

Forget the factory cat. Get a Magnaflow Cat. High Flow one too. We're in Calif so were limited on which ones we can use. I had to use a Calif Approved Cat which has numbers/Letters stamped on the bottom so the Smog Nazi can check it.

[Danglerb]

My first choice would be a Y pipe with a modern high flow cat.

My "own" choice was to put on US 85/86 high flow exhaust manifolds, a custom Y (85/86 has about a 2" offset from stock) and a high flow cat.

[paintballer317]

when i was working on my car, i had the same problem. my problem was that the MAF was not properly sealed to the throttle body, my o-ring was old and kinda flat, i put some of that gell gasket stuff around the MAF and then installed it and that solved my problem

[XLR8928]

In my little town of Pahrump, NV, (suburb of Las Vegas) we don't have smog checks