I have a 99 Oldsmobile 88 and this problem started about 6 months ago the car will just randomly kind of sputter and shut off it will crank over but not start I lose power windows power seats power locks nothing will work I've changed the ECU in and it it ran fine for about 15 miles in the exact same thing again I am lost any ideas would greatly be appreciated

this is when the car is warm it sometimes starts up after 10:15 minutes sometimes it takes two days before I can get it started again I'll check some of the other threads in here but nothing was the power windows in the power seats and everything shutting off

I hope you didn't change the PCM, just because the car didn't start....

The 3.8 engine, is probably one of the easiest engines to diagnose for a no start condition....

Did you do the basics?

When it wouldn't start, check for spark, fuel pressure and injector pulse? Did you check for codes?

Try starting with the MAF disconnected? Check vac line to f/p regulator for fuel? See if the car starts by spraying carb cleaner into the intake while cranking?

If these other problems happen at the same time, I would be checking schematics looking for a common circuit to all......there are a lot of grounds under the carpeting, and if you have a water leak(H bodies are famous for them) and there is water under the carpet, a lot of the grounds, splice packs, and even soldered joints can be affected....

Thanks for the reply, I'll check the maf and other things, I've had water sitting on the drivers side floor a few times in the past I'll check there for ground issues

I just bought a 87 3.8 olds touring sedan, guy told me it would die sometimes and fire right back up, I unhooked the battery to keep the interior lights from draining the battery while I cleaned the interior and after hooking it back up I got the typical turns over but no start, I happened the read online about the TPS being bad causing the car to think it was in Clear flood mode and shutting the injectors off,. Unplugged the tps and it fired right up. try that.

So I think I found my not starting problem due to the grounds underneath the carpeting was soaked with water sitting underneath it was corroded when I unplug the main ground wire, and I had the exact same problem car won't start Windows don't work power seats what is the best way to take care of that can I cut that circuit thing out of there and just wire all together please advise

Yes, many H body cars suffer from this. Some people just clean it and be done, others just cut the whole connector off and solder everything together.