Hi there.... I have a 1985, YES 1985 olds calais, it'* got the 2.5 liter 4 Tech engine in it.

About a year and a half ago, it started stalling out on me, and the code reader spawned an error with the MAP sensor, so woopty doo, I replaced the map sensor and all was fine for about 30 miles. It kept frying map sensors every time I replaced them.

So finally I just unplugged the map sensor, and all was fine other than the hit in the pocket book as my fuel economy dropped by 5 miles/gallon.

It'* been unplugged for over a year and 1/2 with no issues other than rough starts until it warms up.

Now it'* stalling out on me again, as if it was a map sensor issue, but I do not have that plugged in anymore, it'* as if the car is starving for fuel. I pulled the fuel filter and it had a bunch of crud in it, so I replaced it. Car ran fine for 12 days and the stalling issue came back. I can hear the fuel pump kick in when I turn the key. Is it time to replace the fuel pump??? I would do that, except I don't believe that is the issue.

A recent ODB1 scan only shows the MAP sensor error code, but I replaced the O2 sensor anyways to no avail.

Any suggestions?

What is the condition of the catalytic converter? You compromised a major emission component, and noted a 5mpg drop, which a possible rich burn condition, which will clog the converter over time.

Has it ever been replaced or otherwise addressed?

Thanks for the response, and the answer is no, I have not done anything to the cat. Maybe I'll cut it out and straight pipe it. You think that may solve my issue? It doesn't seem like a clogged cat, I've had a couple before... I hate just to junk the car it was my grandpa'* and only has 50 K on it, and not very rusty at all.

It'* age is old, but the mileage doesn't tell me it'* a fuel pump, I'm kinda stuck as to what it could be.

I would verify a bad fuel pump by checking fuel pressure. No point in replacing something unless you know it is bad.

You can verify a clogged cat by replacing it, unbolting the exhaust and running it open as a test (hella loud usually) or you can even remove the oxygen sensor, which gives the exhaust a place to go, especially if the cat is blocked.

How do other maintenance related items look? Cap, rotor, plugs, wires, filters, timing check/adjustment, etc?

Everything is top notch, first thing I did when I got the car is replace cap, rotor, wires, and plugs.

When I pump the pedal constantly when it'* stalling it keeps on going most times, but seems it stalls most when the engine is hot, which could be a clogged cat. I could drive it down the road right now, and it'll run fine sometimes. I was thinking fuel pump, but why would it run sometimes fine, and other times die out on me? Code reader just shows the Map sensor error, nothing else. And the Map sensor has been unplugged for 1 1/2 years.

figure out why the car is messing up the map maybe shorted wire or bad ground or pcm problem. instead of repairing symptoms. like stated rich kills cats.

when u unplugged the map=the computer goes to open loop!! therefore richens the fuel pored into the engine for running. Way toooo Rick= bad fuel mileage. Id get a new map (cheap enough @ rock auto!!) and start looking at the vacumn lines hookup diagram-check out all! and then look into the electrical harness that goes to the map!! all before stsrting & hooking up the new map sensor!! reason im suggesting this is =very uncommon for 2+ maps to go bad!!! therefore id suggest checking out all the map sensor wires 1st!! Voltage checks with a cheapo digital multimeter!! cause the sender is computer & it has a base signal voltage of 5 volts only!! Harbor freight has the cheap multimeters!! heres a site u can go to for an education on the map tests & how to do it all=simple!! =

Sensor Diagnosis & Repair Help for Common Sensor Problems

illalsoadd= what code have u recieved from the map being bad?? 33 or 34?? likely /possible its a vacumn line?? or if frying map'*????????? how r u determining this? have u recently installed a new!!?? map or a used one?? have u tested all the wiring to the map?? easily done = here = Manifold Absolute Pressure MAP Sensors also i have an 1986 calis 2.5 is ur'* carbed ot tb??

I will also ask you to replace / test 1st!! the throttle position sensor!! They can go bad & can just from sitting (corosion) -simple to test & replace & adjust too.

Hey man, this thread is like over 3 years old. The OP hasn't been on in almost 2 years. Long gone now. So please, refrain from replying to posts that are over 6 months old.