Ghost in the machine?

I’ve had this 91 Toyota Previa now for about 7 years and it has been a great car for my needs. However, every few days to few months it will not start–no warnings, no attempt, and only at the most inconvient times. Over the last few years I’ve learned to carry a tow rope and keep a couple friends in mind, but it’s getting a bit old–they’d agree. Early on I had the starter replaced on two seperate ocations, but the problem continues to plague. Recently a button was added to my dash that overides the ignition, but to no avail when needed. The times that it dosn’t start I get dash lights fine but no starter at all. If I go away for a while or overnight it’ll start fine the next time I try, which, by the way, is how seven years have gone by. No one has been able to make it not start intentionally, so whenever it’s getting looked at it’s a guess, and not yet the right one to solve the glitch. Other than these recuring elusive incidents, this has been a very dependible car and still drives like new at 280,000 miles.

Thanks for any remarks, or suggestions.

One more thing: It seems not to be a hot/cold engine issue, summer/winter issue, or dry/wet issue. No obvious pattern is aparent.

dont know if this advice will help but I learned something about a toyota camery that I was driving. we would leave to the store and come out to drive home only to find that it would not start…so after about 5 10 minutes of waiting we would try again. then once we were stranded and about to call a tow company I swear I was pissed I was wondering if i was going to wear out the key I was in the parking lot for over an hour when I saw the light oh…ours was AT so It must be in park to start. the park light did not light up when in park it was caused by something lose anyways after all of that we had to call the tow company back and cancel the order shweeew! anyways in our case it was not in park even when it said it was…curious if your car is AT…? ours was a 92 Toyota camry

when we went to a mechanic they said it was the starter or ignition since we did’nt have the money at the time we decided to just wait each time we stopped somewhere I do believe it would happen more often when it was cold but am not sure just that it sounds exactly like what i had dealt with for 2 years until that one night i moved the transmissin gear up and down through all the gears. thats when i realized what it was in my case

The next time the problem occurs put the shifter in neutral and see if it will start then. If it does then the neutral safety switch is at fault. If that doesn’t help then check to see if voltage is getting to the small wire going to the starter solenoid when you turn the key to the Start position. If voltage is getting to the solenoid then the solenoid is at fault. If there isn’t any voltage then the ignition wire to the solenoid needs to be checked.

Thanks for the suggestions.
It is an auto trans. I have extensively moved the shifter, electric windows, fuses, jiggled wires, knocked the started with a hammer, rocked the vehicle, even had my girlfriend kiss the key in all combinations with no luck. (one time, however, getting towed, key on and in neutral, I was able to start it–power brakes work good!) Whenever the problem does occur I’m usually in some parking space away from home, late at night, in the rain, and in my favorite t-shirt. It is a Previa mini-van so that makes it tight to get at the starter/solenoid underneath, but I’ll be sure to make a copy of this blog to keep in the car, along with a voltage meter. Any other ideas I can prepare with?
Great resource.

Find the ground wire between engine and body. Disconnect it and clean the rust off the body end. If you can’t find it, you can make one. Sometimes the wire is broken off.