shaikhzeep

Good day,

I have this problem and maybe someone came cross such problem.

when i start the car from cold start the car has no issues.Stop the engine and then started again and wont start.It will start after few minutes.

Any one knows why?

Thanks

SeanR

When it does this again, put the gas pedal to the floor and let us know if it fires up.

shaikhzeep

Good day SeanR,

I tried this but will not fire up.I should leave it like 10 minutes and then fire.

Thanks

shaikhzeep

Took the car to mechanic and he told me this is because you have air pressure leak from head to water cooling system and when he depressurize the water cooling system car start.

Is this true

Mrmerlin

to verify what the mechanic said,
you will need to pull the spark plugs out,
then look and see if any have a very clean tip or rust on some parts,
( this indicates water/coolant getting into the combustion chamber)
If they all have a tan gray finish then you most likely dont have a blown headgasket,

Next best guess is you have a bad relay,
it will be one of the 4 running relays
Ignition,
Fuel pump,
EZK,
LH.

before doing any relay swapping,
first clean the battery connections and the ground connection,
and the hot post under the hood and the 14 pin connector
make sure that you have a hot post cover fitted.

Remove both of the coil wires and inspect the ends for corrosion,
make sure that the wires are not rubbing on any part of their run ,
if so then a good chance the wire has been damaged

Also remove the vacuum lines from both of the dampers and the fuel pressure regulator and smell them for gas ,
if you smell gas then one of these is leaking and I suggest to replace all 3 of them,
its also a good time to swap in new fuel lines if your lines are original.

If the intake refresh has not been done then you should consider this as well.

Usually when a 928 engine wont run properly it is due to many worn parts,
once all of the worn things have been replaced then you can expect the engine to run great

docmirror

Let's clarify. This is important to know because your mechanic is indicating that you have 'hydrolock' meaning there is enough fluid in one cylinder to stop the engine from rotating.:

When the car is warm, will the engine crank around, and around and not fire with the key in the start position, or does the engine not spin around at all?

Have you been adding water or coolant to the car regularly?

Have you seen white smoke from the car?

Is the coolant brown and stinky?

Is the oil gray?

Please advise on these questions.

docmirror

Also please edit your first post, go to 'Advanced' and change the title of the thread to indicate the problem:

'89 S4 hot start problem'. Or similar.

shaikhzeep

Good day Mrmerlin,

I will check all what you said.

What is EZK and LH stand for?

Where is the hot post located?

Good day docmirror,

Answering your questions

When the car is warm, will the engine crank around, and around and not fire with the key in the start position, or does the engine not spin around at all? Yes the engine is spinning.


Have you been adding water or coolant to the car regularly? No

Have you seen white smoke from the car? No white smoke.

Is the coolant brown and stinky?No

Is the oil gray?No

Thanks

jthwan22

Look at these 2 links for EZK and LH no start info
http://www.jdsporsche.com/fault%20find.html
http://electronikrepair.com/page6.html

The hot post is right front in the engine bay above black cover and under a blue plastic cap. It is use to attach + jump wire.

Lizard928

Replace the 3 main relays first

EZK Fuel Injection and Fuel pump.

NoVector

This website will help you find the relays

https://www.928gt.com/

docmirror

Excellent. Do NOT go back to that mechanic. He is clearly trying something shady. Now, we can proceed with other issues. Follow the instructions on checking the relays found in these other posts. Relays cause a large number of faults with the 928.

joejoe

One of my '86's is experienceing this problem of hard hot start also. Changed the 3 relays mentioned, and problem has improved greatly. It seems it needs to crank about 4 seconds before starting. My other '86 will start after about 1 second of cranking, so I think there is still something amiss. I think something to consider also is the temp II sensor (may be wrong, and if so someone will say).

MFranke

I'm not sure I'd jump right to head issues. My '88 had this problem in the mid-90s. IIRC the fix involved the fuel system check valve. Back then, Dulles Intl Motorsports in VA did all my work and I recall it was a very quick in and out fix.

shaikhzeep

Good morning gentelmen,

jthwan22, thank you for the links.It is informative.

Lizard931 and NoVector, thanks for the link.I ordered the three relays and they are in the way.

Thanks docmirror.I will do and hopefully the issue of hot start will go.

joejoe, what the temp sensor II.Do you know the number for this sensor?

MFranke, is the check valve you are talking about located on the pump discharge? if not where located?

Thanks