svo-ed

Hello all. Roger from 928sRus told me that this is the forum where the 928 experts are.

I recently purchased my dream car at an estate sale, a black, 928. The car is a 1984 Euro. The car was not running, but I was sure I could get it up and running without much problem. -- Before I continue I would like to mention that my wife is very unhappy with me. I have had the car 6 months and it is still not running. I am in a jam...I need to get this car running soon and for very little money or I will never hear the end of it from my wife. Anyone who is married can surely relate.

Situation: The car has strong spark from both distributors. I can get the car to run on starter fluid. The fuel pump was not running. I hooked up a jumper wire at the relay, but the fuel pump would not run? Just to be safe, I ran a wire from the battery (+) to the fuel pump and it started pumping. I decided to wire a switch that I could activate from the drivers seat. I turned the pump on (by flicking the switch) and cranked the engine. It did not start. I smelled gas so I turned off the "fuel pump" switch. The engine was covered in gas. I noticed a lot of gas in the intake. gas was dripping over the edge of the intake manifold onto the floor. Thankfully I did not burn down my garage.

After the gas was cleaned up and the engine aired out, I ran the fuel pump for 15 minutes. No leaks. The fuel seams to have come from the injectors. Does this seem correct? What might be the cause?

Also, when the battery is hooked up the light on the battery gage is on. (not sure if this is related). It stays on as long as the battery is hooked up.

Lastly, thinking it was likely the computer control unit, I copied the part number (928 618 124 00) and this unit appears to be the same computer from a 1979 car?

Could a bad ground cause run away fuel injectors?

Because the car was not running when purchased from the estate sale, I have no information or history about the car. -- Any ideas? Thank you for your help!
Ed

linderpat

This sounds like a fuel line leak issue - go through all of your lines and ensure that nothing is leaking before you do anything else. You said you have spark, and the car starts from starter fluid, and the fuel pump evidently works, so there must be a breach somewhere keeping the fuel from being delivered where it should be. It doesn't make sense that fuel would come from the injectors - they are mounted into the head. One possibility is that the injectors are not seated properly? Anyway, go through the fule lines, check the injector rail for leaks also, and post pictures of your car and engine bay. Welcome to the forum!


(Guys - we are slow this weekend - nobody else chiming in yet)

linderpat

actually, upon mmore thought, I am also thinking a possible throttle body issue? Anyone else?

Landseer

The idea of gotta show wife it runs, quickly, is pretty much something you need to reject.
Do the refresh work first before trying to start it. Its a relic, don't damage it due to ignorance.

Replace fuel lines first.
Euro has 8ea 50mm long fuel lines, 1 running into each injector. Would probably send injectors to witchhunter for cleaning. Don't score the injector tops when removing the stub hoses.
Here is the process for 84 USA (hoses are same, injectors are technically slightly different.)
http://forums.pelicanparts.com/porsc...placement.html


Spark is good sign. I'd still clean all grounds, check timing belt and cam timing, pull and clean/re-fuse the fuse box before even trying to start it.

84 Euro twin distributor will have a pair of computers, located side by side in passenger footwell.

See this thread for some assist on 84 Euro grounds and a couple fuel lines by passenger header.
http://forums.pelicanparts.com/porsc...-16v-euro.html
You will also see in that thread that your computer part number is correct for 84 Euro.

Mrmerlin

Warning replace the fuel lines first.....

after you replace the fuel lines ,
then you need to start at the back of the car and trace the hard lines up to the front,
this wouldnt be the first car that had a crushed fuel line.
OR a return line.


That said if you have spark there is a strong possibility that the ignition wires are mis routed .

IE the twin dizzzy has a specific distributor for each coil it could be as simple as the coil wires being swapped.

BUT first ,
put the engine at TDC then remove the caps make sure that both of the rotors are pointing to their respective hash marks.

Trace the ignition wires to each plug # 1 is at the front passenger side #5 is at the front driver side on a US car.
There is a wire diagram on the base of the dizzy housing so its easy to figure out

This is due to the dizzy having a small timing belt ,
it can jump or otherwise fail and thus one dizzy wont be in time.

If the cams and the crank and dizzy are all lined up ,
put it back together and crank it with your foot to the floor no pumping,

if it still wont start then remove the coil wire from each dizzy and swap them.
Repeat the cranking with your foot to the floor.

NOTE once it starts dont rev the wee out of it, just let it rumble to life.

The alt light being on may be indicative of a low voltage condition at the battery,
or the 14 pin connector under the hood.
So make sure you have cleaned the battery terminals and the ground points.

Also make sure the grounds for the injectors are connected to the proper location,
and they are clean if not then the injectors wont work

DougM

Also, what are the part numbers on the injectors. The twin dizzy Euro models had specific injectors that cannot be replaced with US model from the same year or the Euro models from previous years. They are specific to the '84-86 EUro S models only.
Could a previous owner replaced the injectors?

checkmate1996

I hate to say this ... but you sure picked a doozy for your first car to start working on...

Mrmerlin

CKmate nice avatar

frankle951

I agree with Landseer, make sure you check the fuse box in the shark, pull fuse and fuel relay check for corrosion.

h011yw00d

Not sure about Euros but when I put a bad used fuel pressure regulator in my car it flooded the intake with gas... freaked me out I must say...

Good luck, man. I hear the twin dizzy Euros are about as much fun as you can have out of bed

Rich9928p

The LH fuel injection module provides the ground that turns on the fuel pump relay. The fuel pump is only turned on once the LH "sees" the engine turning at 50 or more RPM (signal at LH pin 1). Once the RPM falls below that the fuel pump is turned off. The EZF spark module pin 16 circuit to LH pin 1 is the RPM circuit. The tachometer also is connected to this circuit. The RPM signal is a square wave with a period inversly proportional to the RPM, 7V minimum.

So the question is why isn't the fuel pump being turned on when the engine cranks. The reasons can be

a) Blown fuel pump fuse (no 12V source)
b) Open circuit somewhere between the 87 terminal of the fuel pump relay and the fuel pump
c) failed fuel pump relay
d) open circuit between LH pin 17 and fuel pump relay socket 87
e) failed LH injection module fuel pump turn on circuit (no ground)
f) no 30 circuit voltage to fuel pump relay (circuit from the "+" battery terminal to the central electric)

The fuel injectors are powered by the fuel pump relay socket position 87 on the LH-based 928s up through model year 1986. So, with this problem there also is no 12V at the fuel injectors. A properly working LH could be switching the grounds off and on, but there is no current flow because there is no voltage at the fuel injectors.

The best method to eliminate relays and relay control logic is to remove the LH, EZK/EZF (spark module), and fuel pump relays. Check for 12V at all relay socket 30 positions. Next install jumper wires between relay socket position 30 and 87. This "hard wire turns on" everything. If the engine starts, the only way to stop it is to remove one of the jumper wires. Plug in relays one by one until the engine won't start. The relay involved with the no start is either defective or the ground "turn on" circuit is faulty.

And also, any and all fuel leaks must be fixed.

Rich
'93 GTS cover girl
'87 S4
'79 Rescue
'79 Euro track beast
Electronik Repair

svo-ed

All:
I have great news...After working directly via email with Rich from Electronik Repair, I was able to get the car running for $0.00!

It turns out that the problem was a burnt and corroded fuse holder running to the fuel pump. After cleaning it up to a mirror finish and putting in a 16 amp fuse rather than the incorrect 25 amp fuse that was in place the car started up on the first try. A number of you nailed...way to go!

I am going to clean and polish every fuse holder on the entire fuse panel and install brand new fuses before I put the interior parts (shelf, door, rug) back together. -- A number of electrical items are not working correctly or not working at all and I'll bet that cleaning the fuses will remedy a number of the problems.

FYI: Once the car was started, the light on my voltage gage that was lit permanently is now no longer lit when the car is turned off? However, a new instrument panel problem exists: When the car is running, EVERY warning indicator light on the instrument cluster stays lit? ( it cracks me up because it is all in German). Any thoughts??

I would like to thank everyone for your input and help. It appears that 928 Rennlist members are a passionate group of people who enjoy solving tough problems.

I hope some day I will have an opportunity to help another member of the 928 community as you have helped me.

Thanks again.

Ed

ROG100

Ed welcome to the biggest and best resource for any 928 owner in the World.
Rennlist rocks

Alan

Yep - you came to the right place!

But you already know that now...

Alan

linderpat

But don't forget to handle - now - the one thing that jumped out at you, above and beyond the no-start issue - that fuel leak! Otherwise, you won't be doing anything else with the car.