I have an early 944 which over the past 18 months will lose power to fuel pump - many will say to replace the relay which I have done.with the ignition on I have run a multimeter to the relay and this is reading the correct voltage . You can then take a reading from the secondary fuse to find that no voltage is present . My question is does the output of the relay run via the dme unit , then out of the dme unit to the secondary fuse. The problem I have is I can drive the car normally , get in 10 minutes later and the fuel pump will not engage . Is It a short , Is it the dme unit or is it just Bad Earthing- Its starting to frustrate the hell out of me . I hope someone can help me..........

 

Chris,

I just read your posting and I'm wondering if we may have a similar problem. Here is the text of my posting below.

When I first experienced my problem I thought it was the fuse too and removed the old VW style fuses and made up a new fuse holder using a modern type bought from Radio Shack and added alligator clips to the ends. This did not solve my problem. I repalced the fuel pump thinking it was weak, but it didn't help it either.

I have prints from the library on the electrical connections for the 924S, which is very close to the 944 and it shows the fuel pump relay is activated by the DME. One way to test to see if fuse or DME is good, is to wire a 12 V light or LED from the output side of the fuse to the chassis ground and see if it lights at all times. I did this. If the engine stalls after the light goes out, then the something is cutting off power. If the light goes out after the car stalls out, the something else is wrong.

Let me know if your problem and mine could be the same.

Thanks,


Euric





I have a 924S with a 4 cylinder 2.5 L engine, 1988 model year and automatic transmission.

I have a problem that nobody seems to be able to solve.

The car constantly stalls out when my foot is removed from the gas pedal. But, this only happens when the car has been sitting out in the hot sun all day (at work) and then only after about 20 min driving time. The engine seems smooth at all times. When it stalls, I can shift to neutral while the car is coasting, and restart the engine and reselect drive. It goes until I let my foot up on the gas and then back to a stall. When the problem first started, it would not stall out completely and the engine would "start" again on its own after a few seconds of being dead.

So far, I have replaced the spark plugs, the distributer, the fuel pump and filter, and even the DME module (all were original and I thoughtt hey were breaking down). The DME was purchased rebuilt for a different problem the car had about 9 months ago. This problem started once the summer heat arrived. I sent the DME back for testing and it was retuned to me with no problems found.

So, I'm at a loss. Has anyone ever experienced a problem like this? It should be simple to find since it happens when the foot is removed from the gas pedal. What components would be affected by this that I could check next?

Thanks,

Euric