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924T Battery drain


Vehicle Information: Year: 1980; Engine (type, size, modifications): original engine; Total Mileage: 75000;

You've been doing so well with my previous questions, I have one more for now. I've been working on the 1980 924 turbo for a while When I noticed that if not operated for two weeks or so the battery voltage drops to 10 volts or so and of course it won't start the car. I know these 924's were famous for the ground problems. I added the extra ground cables from chassis to battery to engine ground right to the starter mounting bolt, I added a braid ground with soldered ends from the alternator to engine. The starter is new and the alternator charges 14.1 vdc. I removed the ground cable from the battery and inserted an amp meter to check ignition off current flow and found .020 amps of current flow with the key out of the ignition. There is a newer style radio with the memory hooked to +12vdc continuosly also the electric antenna is also fed +12vdc too. I've also replaced the positive battery cable. I don't know whether or not there might be a larger current at times when I'm not there to measure. Another problem I have with this vehicle is on warm or hot days after 20 minutes or so the steel injection lines really get hot from engine heat and the engine will spin ok but won't always start then. Open the hood and let the hot air out and it starts again. I use premium unleaded without alcohol, the fuel pumps have been replaced, and their fuel pressure is 80 psi and maintains 20 psi or better for 20 to 30 minutes after shut down. There is some residual pressure the next day and the car starts pretty much normally then. I thought the problem might be vapor lock in the steel fuel lines so I installed some winshield washer hose over the steel lines to act as a barrier from the heat generated by the exhaust manifold, this helped some but didn't cure the problem altogether. When the car won't start on its own due to the heat, a simple roll start will usually start the car on the first or second cylinder up. Still sounds like battery cable problems, but I'm not sure.

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