Questions and Answers

Infinity Q-45 Dies, Restarts Right Up Q. Hi Vincent, I have a 1991 Infinity Q-45 I recently bought at a car auction with 109,000 miles. It runs great approximately 95% of the time in all regimes. The other times, it will either just die, no codes, with no warning or run erratically for two or three seconds then die. So far it has always restarted immediately after quitting.

Sometimes it will die at an idle, cold or warm, sometimes at cruise, sometimes even when coasting down an off ramp, but most commonly it dies during hard acceleration. The fuel pressure relay was replaced, no change. Do fuel pumps fail gradually or are there likely assorted other issues here?

Thank You!
Cristy

A. If it starts right up after stalling, it is going to be very difficult to determine what the problem is. It has to fail long enough to do some basic testing.

When it stalls we have to determine what is lost, fuel or spark. At this point the best thing to do to accomplish this is to put a fuel pressure gauge on it and drive it until it stalls. Then before trying to restart it, see what the fuel pressure is. If it very low, then we can safely assume it is a fuel problem. Most likely a bad fuel pump.

If the fuel pressure is normal, 34 psi, then we can safely assume an ignition problem. This sounds like a problem that will have to worsen before it can be tracked down.