I have a '93 SSEI. I just recently changed the battery and alternator, because the alternator gets fried about once a year. It ran fine for about a week, and then the engine just randomly shut off while I was driving. Everything on the car appears to function normally, but it will shut off at random times. When it does so, all of accessories stay on, and I can usually just start it again. The check engine light came on the first time this happened, and the code it gave was for the oxygen sensor. So, after a trip to autozone, I replaced the o2 sensor and thought it was fixed. Today my bonnie died on me again, and it would not immediately start.

I am out of ideas of what could be wrong or what to replace. Has anyone ever had similar problems?

Thanks,
Kayley

First of all, I pray you didn't use a Bosch O2 sensor. If so, replace it with an AC Delco. It'* going to start costing you in less than 30 days.

Secondly, even with the O2 sensor wire cut, your car will still run in default mode. Somewhat rich and inefficient, but it'll run.

Problems like yours are usually dirty/corroded battery connections. Disconnect EVERY cable (black and red) EVERYWHERE they go in either direction, paying close attention to the grounds. Using a wire brush, clean the connections, then reassemble with dielectric grease.

Chances are pretty good this is your problem.

possible crank sensor? When mine was dying it would not throw a code. It would kill at any time, and start right back up. Even going down the highway. Just threw it in neutral, restarted, put back into drive. Lost about 5 mph in the process.

Crank sensors USUALLY throw a code, but not always, so that is a possibility.

mine didnt throw one either u might also want to check the harness from the ignition module to the crank and cam sensors they like to have a lot of burned wires let me show you





if u look closely u can see the fried wires thats no longer in the wire loom and for some reason if it felt like cutting off the car did thats due to the wires grounding themselves to the block

The check engine light came on yesterday and while driving the engine was revving on its own.

I checked the engine diagnostic and it threw a code 34.
MAF sensor-voltage too low.

What does this mean?

Thanks,
Kayley

Could be your problem, but even with the MAF removed, it should still limp home. Try gently cleaning the filament with a qtip and rubbing alcohol, but it sounds more terminal than that. Check the sensor wiring harness for damage to begin with, and you may have to change that expensive bugger.

Is there a more in-depth way to check if the MAF sensor is bad? Other cars MAF'* can be tested using a voltmeter on them, cause I'm pretty sure they are all just a potentiometer. Is there a procedure to test ours?

Also, am I correct in assuming the MAF sensor is located on the air intake? anyone have a pic/drawing?


Thanks!
-Kayley