I have a 75' 1.8L and when I bought it, the idle was low, so I brought to the shop here and when I picked it up it idled fine but after 5 minutes of running great it stalls and won't start again. I have replaced the dual relay and the ecu. My mechanic is pretty knowledgable about volkswagens and porsches and he is stumped by this. I'm getting spark, but after it stalls the fuel is erratic, sometimes after cranking it the plugs are wet, other times completely dry. If it sits for a few hours or days, ot will start up on the first try and then does the same thing all over again. it is fuel injected, so I have to assume something is malfuntioning there.

Maybe your vane airflow unit is sticking. If it has ever backfired it can ruin the unit.

try checking the temp sensor #2 mounted in the cylinder head, It will shut down the fuel pump when it warms up if its bad. You will need to fabricate a 1/2 or 13mm deep socket by cutting a slit up the side for the wire.

You set the timer under the passenger seat for 1 hour, right?

Sorry.... long day fixing PCs...

Plumb in a pressure gauge to the fuel rail to check on fuel pressure while you are running your tests.

What Slits said, the flapper door on the AFM may be sticking... had it happen to me... seen it happen to others. If my memory serves me correctly. check this on an L-jet system do the following: During some period of time when the car is not starting correctly, Turn the key to the off position, then turn the key to the ON position only, (Not Crank/Start). The fuel pump should NOT come on when the key is turned to just the ON position. If it fuel pump does turn on, the flapper door is stuck open.

You can remove the AFM from its mounted position, and with the key in the on position, you can check the correct function of the fuel pump circuit by moving the flapper door by hand. Should here it come on when you slightly open the flapper door.

You can perform the previous tests with out the pressure gauge... just be in a quiet place to be able to hear the pump come on.


This does not work on a D-jet set up.

- Dave

CHT