Old but New 928 S4 - tech help needed

[doc cameron]

Hello all. I'm new here so please forgive me if I ask stupid questions or ask stuff that's been asked in the past (I have been using search facility to find some bits).

I have just bought a 1989 928 S4 with only 2000 miles on the clock, last ran in 1997 (for it's 3rd Porsche service). It didn't run to start with so I have:

1. removed plugs, squirted oil into the bores (cranked to distribute into potentially stuck bores), cleaned plugs and refitted - no start/run.

2. Removed fuel line from injector rail - cranked - no fuel coming out - drained fuel tank, drained and cleaned fuel pump and filter - Refilled tank with fresh fuel - engine now starts but only runs at low idle (400ish and rough) - If I touch the throttle, the engine dies.

3. I want to remove the injectors to check for blockage and functionality. I removed the electrical connection and the two end hoses and tried to prise the rail off in one piece complete with injectors - the thing is stuck firmly down. Do I just keep pulling or is there a secret. I did read a post talking about a '79 injector pull and talk of sockets to remove the injector - I cannot visualise what this means?

4. I have a constant 'clicking' noise from below the inlet manifold with the ignition on (and when running). it sounds like an old fashioned electric fuel pump running permanently - is there any kind of solenoid under there? Maybe on the throttle body?

I live and work in Brunei, Borneo - not much in the way of service/spares here so I cannot easily go and change/buy parts.

Cheers to all,

Doc

[Danglerb]

Congrats, sounds like several fine low mileage cars were recently sold in Brunei. Check the link below to get in touch with another owner, and read the advice given to him.

Finally got a Porsche 928 - Rennlist Discussion Forums

Clicking noise would be the injectors working, they are indeed noisy.

My suggestion would be to stop trying to get it to run, and start bringing the general preventive maintenance up to date. I would also check the coolant to make sure the PH isn't bad and the engine damaged internally.

[Mrmerlin]

before you start pulling out injectors try adding some techron to the fuel, you can just remove the injector connector to find out if its not working. ( note it is normal for the injectors to click when they are working)
If you do need to remove the injectors .
First blow out the injector seat with compressed air this will remove any small particles that would otherwise fall into the cylinders.
then spray the bases with some WD40.
remove the injector rail bolts and the top clips to the injector/rail
remove the fuel lines
then gently pull up the rail should come off the top of the injectors
then you can gently walk the injectors out with a screwdriver prying on the bottom of the injector
use a protective cover on the cam cover so it wont get damaged
do not let fuel spill on the intake or the cam cover as it will discolor it
I would be first opening up the aircleaner to inspect for a animal nest under the intake and also on top of the cats a nest here will quickly cause a fire.
Clean the ends of all elex connections including the fuses and relays with a eraser also inspect the battery connections and the Hot post connections and the 14 pin connector above it

[doc cameron]

Danglerb/mrmerlin,

Thanks for your help so far. As we're in 12hour + time zone difference I just got the replies this morning, last night I did some more work:

Removed the injector rails, injectors all cleaned, blown through and replaced. I disconnected the fuel line to the rail and checked for fuel delivery - none. I bridged the terminals on the pump relay and pump works OK, replaced the relay. The car still wouldn't do more than start, idle for a few seconds then died (it will do this all night!). I even tried to start with the relay bridged to ensure constant fuel supply - still no more than a few coughs and splutters.
A friend who also bought one at the same time feels it may be the pressure regulators on the fuel line that are causing the problem?

With reference to the 'clicking' sound, my friends does not do this. Let me explain better: With the ignition key turned to the pre-start position, the clicking noise starts (but not always, about 9 times out of 10), it continues even when the engine is running. (I think if injectors were causing the noise, they should only be activating when engine is cranking - unless one is stuck in the On position electrically)? - But I will keep an open mind...

Cheers,
Doc

[Mrmerlin]

if you turn on the key to the run position with out the engine running and then the injectors are clicking then you have a failed LH brain
To test for fuel flow remove the cap and ball from the right front fuel rail put a rag under the cap so you dont lose the ball it will fall out if your not careful.
Put a jar under the outlet and with a helper crank it over you should have fuel come out
But your brain is fried.
another check is to see if the tach jumps when you crank, no jump LH brain no good

Where are you located??

[Danglerb]

Brain service and info in link below.

Porsche 928 Fault Diagnosis - JDSPorsche

[sparky rowan]

Don't try starting that car until you have changed the T-belt and WP I would go over all the belts and hoses before I did anything else. Sounds like you got yourself a hell of a car, so take good care of it. How about posting some photosGood luck

[Landseer]

I'd clean all the ground point screws/wires located throughout the car before doing much.