1999 PA Ultra; bought used and have not had a belt on the turbo since I bought it a couple years ago.

Trouble: At first, I thought my tranny was slipping, at highway speeds. It did this for a while, but then one day shuddered and died sitting in the bank line.

Took it in and was told it need an O2 sensor. This didn't fix the problem. Then was told it just needed a tune up. This didn't fix it either, but this is where I noticed my mileage went from 26 down to 19. Drove it for a while, till it left me stranded on the highway. On this occasion, it was smoking black out the exhaust, had very little power, and finally died. Had it towed in, and was told it had bad IAC and MAP sensor, but that there might be more wrong with it, and I should just go car shopping. I think the mechanic was afraid to make a diagnosis, since his previous work had only cost me money, with no real results. So I replaced the IAC and MAP myself. I also ran some injector cleaner through it, as I read if there is black smoke, an injector is likely clogged. It now runs smoother at idle, I can drive it on the flat, and the black smoke seems better. But if I need power to climb a small hill, forget it. It just wants to stall out. It doesn't die, but acts like it wants to. Any ideas?

Thanks.

This is going to be difficult to diagnose because your SC belt is not installed.

When was the last time you cleaned the MAF sensor?

Forgot to mention I cleaned the MAF too.

sounds like crank position sensor, does it take a long time for it to start after it quits? the only other thing i can think of that just shuts the whole car down like that is the ign cont module. both are attached to the engine get heat soaked and die. both cut spark when they die but can be fine when they cool. so if you have a heat gun i would carefully heat up the icm to see if it quits. the cps isnt so easy to get to

Thanks, JW. I don't think it'* heat related though. I can start it and drive around my small addition when it'* still cool, and the car still acts the same.

As for starting it back up after it dies, I don't generally drive it till it dies, as I don't want to get stranded on the road. When it did die, it started right back up, but had no power, so I ended up calling a wrecker.

It will sit in the driveway and run for hours at idle. If I gun it and let off the gas abruptly, it almost dies, but catches itself and comes back to a good idle.

you have a fuel pressure tester, almost seems like the pump or regulator may be losing pressure

A bad CPS doesn't result in a loss of power, it shuts you down. It almost sounds like you are experiencing a misfire under load. Is the CEL coming on and/or flashing when you experience this loss of power? If not, do a visual check of your exhaust sytem for any damage that could create a restriction, pull the vac line off the FPR and smell for gas, change your fuel filter, and check for fuel pressure.