I just bought a 98 XK8 with 86,000 miles. The engine upgrades were completed in the past. This morning during an acceleration, the Engine Failsafe mode legend came on and the yellow light under the speedometer came on and stayed on . The cruise stopped working, but nothing else bad happened. I drove it to work, shut it off and started it back up and the light didn't come back on. I drove it home with no light and all fine. Tonight I was cruising about 40mph, I heard a series of quick beeps, the car died and I coasted to a stop. No unusual warning lights of any kind. The car would not restart. I turned the key completely off and when I turned it back on it started and ran fine again. At least it ran fine long enough for me to get it home, park it, and get in my truck. I had seen the yellow light under the speedometer flash on once previously during some hard acceleration, but it went right back out with no problems noted. Does this point to a particular problem?

 

This sounds like a battery. low voltage does crazy things with these cars. Have the battery checked.

 

The voltmeter shows good voltage at least when the car is running. I don't know that I have paid attention when the car is turned off. Would a weak battery cause problems when the alternator is putting out good voltage while the engine is running? Thanks

 

You need to get a ODBII reader, most here use a PLEX bluetooth one and the Torque app for Android but general codes can be read with a cheap one. This is a must when working on these cars. I don't think it would be the battery at this point but you can check it with a meter and post the morning standing voltage. Forget the gauge it will only provide a rough value. Since the car restarts it wouldn't die while running if the alternator wasn't charging, also you'd see a red light on the gauge if the alt wasn't working. You need to read the codes and post here and we can help you from there.

ps, someone will be by to ask you to register in the new member area.

 

I called the autoparts store who told me they can get the codes but only if the "check engine light" is on. Is there a way to retrieve past codes if there aren't any current faults?

 

With a new-to-you purchase, I would replace the battery, do a hard reset, plug and unplug the throttle body connectors a few times and sandpaper the chassis to ground strap, the negative and positive cables to the battery and the bulkhead connection.

That will put you in a good place to see if there is really a problem, or if the connections were just sussed. Should take about 2 hours to do all of that.

 

please forgive my ignorance. I'll try to figure out what a hard reset is and try it. I understand also the blue tooth code reader will capture faults as they happen so I will look for one.

 

Klynn my 1998 had same issues (except engine dying) when vacuum hose to top of throttle body came loose. Give it a quick look.

 

Hard Reset, remove negative battery cable from battery, while holding it pull it over to the positive post of the battery and make contact for 15 secs. Note the positive cable should still be connected to battery.

You will need to reset window limits (hold window down button till you hear click, then up and hold till you hear click) do both sides.

Follow through with the above items as well checking TB (throttle Body) connections

 

The car is in a garage I have access to. I have the Bluetooth OBDII coming. I'll get time to try all the suggestions and see if I can catch some codes in the next several days. I really appreciate all the help with this. It may turn out to be an enjoyable, if challenging endeavor to get, and keep this running. For the most part it runs great now, just the sudden dying got my attention. If I didn't have the help it may have turned into the cool looking driveway ornament I told my wife it would be even if it didn't run before I bought it.