Is clock saying it's time to check Jeep's wiring?

Q I have a 2001 Jeep Wrangler, a 4.0-liter manual. I stopped for about three minutes to drop something off. I turned off the vehicle, and when I turned the key to restart, completely dead. I tried turning the key a few more times to the start position ... and the starter finally lit up and it was running again. I noted the clock reset but not the radio presets. The trip odometer reset again. With the clock losing power, I'm thinking the problem might be deeper into the electrical system beyond the ignition switch or clutch safety switch. The mileage is barely over 19,000, but it has the original battery.

A Besides checking the obvious -- battery, cables, solenoid and connections -- it's worth noting that about 95,000 Wranglers built in 2001 and 2002 were recalled to replace an ignition switch. Have you checked with your dealer to see whether your vehicle was involved in this recall?

Although the trip odometer and clock reset could point to an electrical problem with the dash harness, the ignition off-draw circuit/fuse or the accessory relay, many electronic items will shut down when available voltage drops below a certain threshold. A poor connection between the battery, body harness, solenoid or starter might cause enough of a voltage drop to generate this scenario.

If the recall does not involve your vehicle, give the "wiggle test" to all the battery cables and connections, clean and freshen any with even a hint of corrosion or looseness, and try voltage "drop tests" from each connection from battery to relay to solenoid to starter. Any drop of more than 1/10th from one connection to the next indicates a problem.

Q I have a '93 Mitsubishi Eclipse GS that has begun stalling. I will be driving along or idling when the rpm gauge drops to zero. It doesn't sputter, or idle hard, it simply drops. If I leave it be, the car dies. However, if I press the accelerator all the way to the floor, the rpm returns. It usually won't stop doing this until I open the throttle to about 4,500 rpm, then it stops. At first I thought it was the fuel-pressure regulator, so I changed it. The car ran smoothly for a week. Now it's doing it again. Maybe a faulty fuel pump? Injectors?

A Possibly, and the fuel pressure regulator could cause such a symptom. But with a leaky regulator, I would expect a more consistent symptom every time you sat and idled for any length of time.

The good news is that a simple fuel-pressure leak-down test will identify a leaky fuel pressure regulator or injector and will confirm that the fuel pump is delivering proper fuel pressure -- 38 psi at idle with vacuum connected to the regulator, 47 to 50 psi with unregulated pressure.

But I suspect the idle speed motor might be your culprit. Look closely at this motor -- a high-resistance connection between the connector and engine ground can cause erratic idle characteristics. My Alldata database pulled up technical service bulletin #94-13-002 that describes this issue and calls for using a scan tool or an analog voltmeter connected to the diagnostic link to check for fault code 15, which would confirm a problem with the idle control motor.

Q I have a 1977 Corvette with the L-82 engine, automatic transmission and 53,000 miles. The car is extremely hard on the ignition "module" in the distributor. They seem to fail after just one or two thousand miles. I owned a 1976 'Vette for 20 years and had to replace the module only once in 20,000 miles. Now I must drive around with a spare module and a couple of screwdrivers. I know this part was used in many GM vehicles. What might be causing this one to fail so often?

A My best guess is poor-quality replacement modules and/or excess heat. It might be worth checking a couple of other potential causes.

In that generation of GM vehicles, the magnetic pickup coil inside the distributor, which connects to and feeds the "trigger" signal to the module to fire the coil, often failed because of a small internal break of the wire in one of the coil's leads. Since these wires flexed every time the distributor advance mechanism rotated, it was common for this small coil to develop an intermittent characteristic in which the engine would momentarily shut down as the throttle was opened and the advance mechanism in the distributor added ignition advance. Check the continuity through the pickup coil while wiggling its two leads back and forth. A loss of continuity warrants replacing the coil.

Also, excess play in the distributor shaft might be causing some type of arcing inside the cap. Maybe something like this is contributing to short module life. But again, with so many "off-shore" and "aftermarket" modules available, make sure you're buying and installing a reputable component.