Questions and Answers

Our Favorite Fiero... Again

Q. Vince, the mechanics, I have looking at the Fiero are considering running a direct wire to the fuel pump and controlling it with a toggle switch if they cannot find this short? (they also added the advantage that no one could steal the car if they did not know where the switch was?) So tell me my friend......... is it time to get a new mechanic???? Or is that a valid plan "B"? OBVIOUSLY my concerns are, can the short get worse unfixed, with the direct wiring of the fuel pump is there a risk that the pump could ever burn out? if the toggle switch is left on, what's the worse that could happen, just a dead battery? Or once again is it time to get a new mechanic?................:)

My condolences,
Pat.........:)

A. Pat, I think it's time to get a new mechanic. This one is trying to, possibly, get you killed. It is possible to bypass the whole system and run directly to the fuel pump. And by doing that you run the risk of waking up to a dead battery, and ruining the pump, if you forget to turn it off. But, by running a separate wire and switch to run the pump, you also bypass a very important safe guard.

The fuel pump circuit is tied in with the Air Flow Meter. As long as there is air going into the engine, the pump will run. As soon as the air flow stops, the pump shuts off. Why is this important? Well, I'll tell you. Say you're in an accident and a fuel line ruptures. The first scenario is as soon as you have the accident, the engine will die. If the engine is still running, the loss of fuel pressure will kill it. In either case air will stop flowing into the engine and the fuel pump will shut off.

If the fuel pump keeps running, you will have a high pressure fuel leak and it's almost a sure bet that there will be a fire that will burn that car down in minutes. I have seen it happen. When I was first starting out as a BMW Technician years ago we had a BMW 530i towed in that had a fuel leak and caught fire. There was over $12,000.00 worth of damage to the car which was nothing compared to what the Lady driving it lost.... her 18 month old baby. The high pressure fuel hit the exhaust manifold, caught fire and completely engulfed the car in flames within 60 seconds.

Please.... find the short, fix it right and let me sleep at nights. I'm getting to old to lay awake at nights worrying about my friends.