Beverly, my 94 3.1L Century from hell.

[carchick]

Hey y'all. I'm new to this forum. I've spent HOURS trying to find an answer to my dilemma. I have found a few that I am going to try in the morning. A little bit about me before I tell you about my car. Yes, I'm a girl. I also have my associates degree in GM ASEP. I have a few ASEs, working on being a master tech. But this POS has me stumped.

Alright. So the car has about 180,000 on her. I was driving her one day and I noticed a LOT of hesitation at random times. When I get stopped at a light or sign, she sometimes will start hesitating and surging intermittently. Sometimes, she'll stall out. Most of the time, I can put it in neutral and she'll start right back up. A few times, I have to put her in park to get her started. There has been only one time where I had to turn the key to off just to get her on. Whilst driving down the road/highway occasionally, at any speed, it will hesitate like a mofo, no throttle response (like she's flooded) but still be running. Sometimes when that happens, either it will stall or eventually normalize. It seems to happen randomly. There have been only a handful of times that it will have no problems whatsoever. Yes, the CEL is on, but being the stupid OBD 1.whatever it is, my local GM dealership wants to charge me a lot to read it. Being a girl, they will try to sell me on something I don't need.

I have done a FULL tune up to her after this started happening. I have replaced the IACV and most of the vacuum lines, PCV valve, and I've thoroughly cleaned the throttle body and MAF sensor. I plan on replacing the MAF and maybe the TPS tomorrow. I'd just like some more input, just in case none of my ideas work. I'm so close to taking my Barrett to the block and being done with it. Thank you ahead of time, for any ideas or suggestions y'all have.

Have a good day/night!

 

[HotZ28]

Congratulations on your accomplishments in the automotive technical world, and you should be proud! IIRC, with particular car, you can still read the codes by jumping the A/B terminal on the ALDL link. If not, you would need an OBDI/OBDII capable scanner. You can do a search for some of these multiple capable scanners under my recent post in the LeSabre/PA forums. I would also have the CAT checked for restrictions. Click Here for an example.

 

[carchick]

Thanks for your input. Unfortunately, the CAT is clean. I replaced the Mass Air Flow sensor. It seems like its happening more now since I replaced those parts. Its almost like its starving for fuel or air. I'm preparing to do a fuel pressure check. I'm pretty sure its the original fuel pump. I'm so not looking forward to replacing that. UGH!! It's really pissing me off!! Thanks, guys.

 

[Jerry98]

Just curious if you got around to replacing your TPS?

 

[Fieromaster]

Id look at your crank sensor... with that mileage they're notorious to fail past 150k.

-Mitch

 

[jaspergreen1998]

This is actually my first post here, too. I had a 1992 Century with the 3300 V6 that had similar symptoms, about 3 years ago. It would stall out, sometimes at 25-35 mph on the street, and be impossible to restart for a while. It was around 160K when I began parting it out for the other 3300 Century in the family.

I replaced plugs and wires, MAF sensor, PCV, one of the ignition coils, and just plain bypassed the catalytic converter altogether (around that time there were a rash of thefts of them, if I'd just left it in the right bad neighborhood some jackass with a sawzall could have saved me a little trouble 🙂)

The shop I took it to figured that it was a bad crankshaft position sensor. It wasn't an expensive part but it would've been labor intensive. (Pulling the harmonic balancer etc.) I wouldn't be surprised if you had a crank sensor going out.

EDIT: Just thought about the OBD1 issue you mentioned. Around me, parts stores offer free trouble code scanning, I assume using a retail-grade OBD2 scan tool. They may or may not be able to scan OBD1. If you have the Haynes/Chilton book, it should have instructions for either cycling the ignition or using a paperclip to connect two terminals on the OBD port, which will flash the "Service Engine Soon" light in a sequence. For example, four flashes, a short pause, and four more flashes, would be a code 44, which I think was "oxygen sensor." I could be wrong.