Car is a 1989 Olds Royal Broughm 88 with the 3.8L V6. Runs great 90% of the time. The other 10% of the time it runs like crap. Engine feels like it's about to stall under acceleration, check engine light comes on, the air conditioner or heater will not blow air. Seems to be luck of the draw, sometimes you turn the key and everything runs great and the air works, the other times it has the problems listed above.

I have had the car in for service but of course when they checked it, it ran fine and no idiot lights popped up. The battery, starter, and alternator tests fine. My guess would be the computer, but I'm not a car guy so it's just a guess. Any suggestions?

It doesn't matter, as when an error is found while running, the trouble code is logged when the 'idiot light' is displayed.  It doesn't matter if the engine performs fine for the mechanic, that code is still stored in memory (unless you've reset it by disconnecting the battery since the last time it happened).  They should know that and should have read the code.  

That's what I thought, but they said they found no error codes in memory. If the computer is going bad, perhaps the memory is getting dumped?

Looking into buying/borrowing a reader so you can grab the codes in real time when its happenning.

When it's doing the  "Engine feels like it's about to stall under acceleration" how is it running at idle, in gear and park, stopped?

Knock the glass out of it, weld a roll cage into it, strap on your helmet and put that ghetto sled in a demolition derby! Then go buy something cheap with a 100,000 mile warranty. I dumped my Towncar about a year ago and haven't had to worry about the what ifs since.

If this isn't an option then I wish you the best of luck chasing the gremlins out of your Olds.

That's true for cars made after '95 that have OBD II (On board diagnostics) but not for older cars like this with OBD I.

The good news though is you can generally read the codes using a simple voltmeter and a jumper wire. (see shop manual for details). This way you won't have to take it to the mechanic while it's doing it.

My guess with something intermittent like that that it's electrical.

Good luck.

I think I found your problem.


You own an Oldsmobile.

You don't even need a reader on that era car.  If you have a "Chiltons" manual, it will tell you what to do.  You simply have to complete a circut between certain contacts on the plug with the key on 'run'.  I used a paper clip.

The light will start blinking codes.  If I remember correctly, it will always blink a certain sequence 3 times indicating the start of the codes, and that same sequence 3 times indicating the end.  Thus, if you see these back to back, there are no codes.  Each sequence is displayed 3 times.  If you see a sequence of long and short between the start and end sequence, write the pattern down, as that is the code.(this will be displayed 3 times as well)  It can then be looked up.  You have to have the GM code list, but they are easy to find, I have one.

Don't be scared to do this, all you have to do is be sure you're making the circut across the proper contacts, and you should be able to find which ones they are fairly easily.

All my GMs have been older than '95, and they all stored the code for later discovery.  

She's dead, Jim.

Sorry, guess I should have said that cars won't necessarily be able to store codes unless made after '95 where they are required to do so.

Look for a vacuum leak, probably a cracked line leading to the vac canister, and the climate control system. If I remember correctly,GM was using small nylon tubes instead of rubber for their vacuum lines. These cracked very easily.

Also, I'd check the basics. Cap, Rotor, Wires, etc.. The GM FWD V6's are not fun to work on, when the rear bank is concerned.

Good Luck.

Meplat-