DME relay - interesting outcome

[crosby50]

In the last two weeks my Carrera stalled twice on the side of the road. No sputtering, just dead. Both times it started right up after letting it sit a minute. Lucky for me, I did as you Pelicans suggest and I had my spare DME relay. This morning, I spent less than ten minutes replacing it before work. Since it was raining, I took the old DME relay to work with me and waited until tonight to see how the car ran.

At work, I opened the relay and looked inside. The relay doesn't look too bad. One of the top two joints may have a small crack (hard to tell) and the board looks a little dark in some areas. Other than that, the relay looks fine to the naked eye. I was actually worried that I hadn't found the culprit, though I know the cracks can be hard to detect.

Next, I came home and took the car out for a spin. The first thing I noticed is how quick it cranked. Then, even cold it seemed to run much smoother. Once warm, I started to lay on the throttle. Is it possible that my car has gained some horsepower? Is it possible that the engine runs smoother? Is this just a placebo effect? Either way, thanks Pelican for saving me time and money.

[ZOA NOM]

The DME relay provides voltage for the fuel pump, as well as voltage for the injectors, on two isolated circuits. A poor solder connection could drop some of that voltage and cause the pump to run a little weak, or low voltage to the injectors. I don't think you're imagining things.

[ianc]

I would be inclined to put it down to the placebo effect. As long as the injectors receive sufficient voltage, they'll open and squirt fuel. If not, not.

The fuel pump might be a different story, but under normal circumstances it can deliver more fuel than the engine can burn and the excess is sent back to the tank. If the fuel system were excessively restricted, you would have noticed the starvation under high-RPM or high load conditions.

Glad it seems to have cured your problem though!

ianc