Fell into the trap! Bought a non-running 928...need help

[BoiseShark]

Hi all...Glad to be a part of your forum.

I recently purchased a 1979 euro 928 and brought it home on a trailer. The PO...or should i say 2nd PO was in the process of turning it into a track car by stripping out all the interior to bare metal. I have carpet, instrument cluster, two seats and a steering wheel...yippie... the immediate PO could never get it running.

Anyway, to my problem. I sat up tonight and read gunner's thread from start to finish thinking i might find what I need. Came so close.

The PO also took out the fuel tank and did not have the correct fuel pump. I heard it run...like everyone who buys a non running 928 by the PO dropping a little fuel down the air cleaner and listening to it run for 3 or 4 seconds. I had to have it.

I rigged up a fuel tank in the back hatch and found a running CIS fuel pump. jumpered the relay and got nothing. I undid the incoming fuel line to the distributor and had fuel.

I removed an injector and no fuel. Removed the FD and (i'm a take it apart guy) figured out how the thing worked by taking it apart...yes, i broke it in half, replaced the orings and put it back together clean. (will use the indian head if it starts to seep...i figured the thin steel plate was the gasket.)

turned the key and it fired right up and reved to about 1500 rpm and then dies.

tried it again and could feather the pedal and keep it running but very weak...the farther i stepped on the gas the faster the engine would die.

I will take pictures of my project and post tomorrow. I love the enthusiasm of this forum and I absolutely can't wait to get this shark running (and then tint the windows to avoid having to build the enterior for a while...lol)

Any help would be appreciated. I can't find the right fitting to test for fuel pressure so i'm kind of stumped on that one. We have two kits at our shop and neither one has the correct fittings.

I'm suspecting the WUR and will try to find an early model rabbit one in the morning to swap it out trial and error....we have plenty of those lying around.

Rob btw

[davetr]

good luck

[harborman]

Sounds like a very big project. Are you intending to do a complete restoration? Maybe you need to sit down and figure out how much this is going to cost before investing any more.

[AirtekHVAC]

I feel your enthusiasm, as I am performing a full restore on a 1978. At least yours runs..lol...I have to use a breaker bar and socket on the crank to see my motor turn...but I am getting there.

I am doing it for the fun, and passion of a project, not so much for the initial investment. I'll gain more in knowledge and experience than I will spend on parts!

Good luck! Lots o good people and help here.

[JK McDonald]

Hey BoiseShark, Don’t worry – we will help you get your CIS fuel system straightened out. It may seem a bit daunting at first but it works on a relatively simple pressure balancing principle. Before you even start switching and swapping parts around you MUST know the various primary and (Hot/Cold) control fuel pressures at several important points. Other wise you will be troubleshooting “By Guess and By Golly” and potentially throwing money at an unknown target.

First get yourself a CIS pressure testing setup which will include a fuel pressure guage, multiple hoses, small brass switching manifold and lots of different fittings. They are actually very inexpensive and you’ll use it for diagnosing and tuning things up for the life of your car. JC Whitney sells a nice reliable setup but shop around.

Once you have some CIS test point readings, everyone will be able to make some recommendations on getting your engine running right.

Keep us in the loop and good luck,
Michael

[MPDano]

Your almost there. Your running on your Cold Start Injector, which is why it's dying after a few seconds. Your issues will be fuel delivery. Remove or clean all the tiny screens, there is one on the intake side of the WUR and almost always clogged on non-running CIS cars. Pull all your Injectors and clean them to see if you can get a good spray pattern. I put carb cleaner in mine and the used an air compressor to push it through.

CIS is very finicky about not being run. On all years, you must make sure the Fuel Tank is totally clean.

[DPW928]

You may want to try running a good fuel system cleaner through it. The injectors could be partially plugged and cause the problem you are experiencing. Also, check for a large vacuum leaks. The rubber sleeve between the lower plenum and the throttle body, a bad brake booster, or leaks at the bottom of the rubber sleeves that connect the intake tubes to the upper plenum are common sites for leaks. Also check the air sensor plate (in front of FD) to make sure it is clean and moving freely. If not centered in the venturi, it can stick and cause a drop off.

The CIS test gauges are available from 928RUS, Ideolas garage and JC Whitney's. Once you determine the control and system pressures are OK and the system is clean with no vacuum leaks, the A/F ratio should reset. There are two methods to set it without an exhaust analyzer. Let me know when you get to that point.

[Danglerb]

This guy doesn't sound very daunted. Not with the swapping wurs out of rabbits etc.

[DPW928]

Originally Posted by Danglerb

This guy doesn't sound very daunted. Not with the swapping wurs out of rabbits etc.

Depends on whether the part numbers match. If not the factory setting of the control pressure may be off. Also, IIRC the 79 euro's WUR had a vacuum diaphram that increased control pressure when the throttle was closed (deceleration).

[JK McDonald]

Hey BoiseShark, Once you have a CIS pressure testing set up, you can accurately test and make adjustments to the primary pump pressure (set within the fuel distributor) and the control pressures (set by the WUR). The cold to warm control pressures on Bosch CIS cars are pretty broad and forgiving, it is the final hot or "run down the road" control pressure that needs to be set precisely for the best power and economy.

Although each WUR is factory set for a specific P/N and vehicle application, it is the thickness of the internal bimetallic bar, balance spring (with or without vacuum assist) and the heater element windings that's the major difference between most parts. In a pinch you can swap the WUR between engine types (4cyl vs 8 cyl) but your adjustment range can sometimes throw a few intermediate (cold to warm to hot) pressure control problems into the mix.

If you want to try and swap out the WUR from another car - there are several good Pelican Part write-ups with photos that demonstrates the basic procedures you would use to correctly set-up the control pressures needed for our V8. Naturally you'd want the specific 928 fuel system spec's for your vehicle on hand before trying to get too far afield.

Good Luck, Michael

[BoiseShark]

Thanks for all the feedback guys. The general thought is to get a fuel pressure guage before i go any further so that is what I will do and get back when I can give some good data.
I'm going for a restore....not a stripped frame paint job or anything. Just aiming to get it back to the way it should be...not showroom, just 33 year-old runner.

I noticed today that the rabbit WUR did not have the vacuum assist just like DPW928 pointed out. I did a quick install anyway to see if there was any difference and it made none.

I hope to get back soon because that will mean I have found a pressure guage.

and no, I am not too daunted and also have no clue what i'm doing. Great combination.

Be back with the numbers. Here are a few pics of her

Notice the BMW seats....hybrid!

[AirtekHVAC]

The seats actually look good....in fact, the whole car looks better than mine..lol...

Please report your adventure, as I am not far behind as far as fuel goes...got to replace my fuel lines and repair a couple hard lines, and then put my tank in, etc....I hope I dont have to do too much "calibrating" with the CIS. I found a good bosch manual online for the system...I'll try to find where I got it...

[whatudrivin]

I'm in the same boat as you. Got an 82' that doesn't run, but am hopeful that when I can get the extra $300 I need to order parts from Roger that I will be able to get her running. Time will tell on this one for me. And you as well. Best of luck and can't wait to see/hear a video of it running.

[BoiseShark]

How cool is this...you guys are at the same point as me. I am quickly figuring out the CIS system (I think) Airtek, so I will try and help you as much as I can as we go along or vica versa... btw...i've broken every vacuum line that i've touched. replaced them all today.

and whatudruvin, I hope you can get her runnin along with us. What part are you ordering? What do you think is the problem(s)?

[924CarreraGTP]

The name of this thread sounds like "Suspicous Minds" by Elvis Presley. lol If it starts and runs, I agree in cleaning the fuel system. Run B12 Chemtool. Screw fuel injector cleaner, or Seafoam. Get Berryman's B12 Chemtool and run it through the system. It may clear up immediately and run perfect or it may take time. Keep starting it, and keep running clean fuel and B12 into it.

[Danglerb]

Make sure you get a fuel gauge set made for Bosch Kjet, you need the special fittings and valve system to measure differential pressures.

Roger at Home - 928's R Us Porsche Parts Store has one as cheap as anybody.

[AirtekHVAC]

Thanks for the tips guys...looks like we have a support group within a support group here...lol...

I just ordered all my vacuum lines, so I will going on that adventure in the next week or so...

I am probably moving soon, which is going to screw me on the project, as I will have to put the car in storage for about 8-10 months....

But on a positive note, I have convinced the wife and builder that the workshop needs to be built while the house foundation is going up so we have a "place to store our stuff" ... lets see how I can get 25 years of house crap crammed into a corner, and still have room for the 928 and tools

[whatudrivin]

Originally Posted by AirtekHVAC

lets see how I can get 25 years of house crap crammed into a corner, and still have room for the 928 and tools

And still have room to work on it!

As for my parts I don't really have anything wrong with my car. It's an '82 so I don't have all the fuel issues like you guys are having.

I am ordering all new water hoses for my car, thermostat, and a in tank fuel screen. That is about all that I need. Other than cleaning my fuel tank and replacing the vacuum lines. But other than that I think I am good to go. I hope so!

[BoiseShark]

That would be nice W'drivin. I hope you're right.

I found a guy in Portland that has two old 928s (plural..not S's) and he is willing to let me pay a flat fee and take whatever I want off either of them...I'm not telling what the flat fee is...lol...but it's reasonable to strip both cars of interior and exterior parts.

I'm headed there now...about a 9 hour drive from me.

I will read this post tonight when i get there and I know I'm opening a can of worms but I know we all need hard to find parts sometimes so I'm putting this out there....

I any of you need strange little parts....not major takedown stuff-engine, transmission etc...post them here and I will see about getting them for you. It's not going to cost me any extra and If i don't need them...you got em.

One is a 79 auto and the other is an 82 stick. I'm not sure exactly on the year of the second one, but it's close.

Off I go on my big adventure!

[whatudrivin]

I wish I knew what I needed.... If one of them has black leather interior I need a drivers rear sun visor thing.

But I have already done quite a bit on my car already. I have a thread on here showing everything that I have done so far. New to the forums and Porsche

But it may be a month or 2 before I get the $300 I need to order these parts. =( And it is making me really sad. So close too.