1992 Volvo 240 Odd Problem
 

Hi all, Last night while driving home on the highway, the Check Engine light came on on my 1992 Volvo 240 DL. I parked it in the driveway and waited until this morning to check it out. I first checked my fluids, even thought I knew that wouldn’t be the problem. The antifreeze was very low, even though I checked it a few weeks ago, so I replaced it. I checked the engine codes and got 322 (Airflow meter hot wire), 221 (Heated Oxygen Sensor(Rich mixture/part throttle)), and 231 (Lambdfa adjustment). The first thing I figured to do was check the fuse for the O2 sensor (fuse 6). The fuse looked like crap so I replaced it with a new copper one. I checked to make sure the other fuses were ok and then started the car. As soon as I started it, the Check Engine light went off, BUT the car died immediately. I tried again, and the car just barely starts and then dies. If I gas it right after starting it, the engine will rev, but then it dies as soon as I stop giving it gas. Does anyone have any idea of what is going on here? The only thing I did was change fuse #6. I checked to make sure the other fuses were still in place (esp. the fuel injector fuse #4) and everything is fine. I’m a student and don’t really have much money to fix this so I’m really trying to figure it out myself. Thanks in advance for any help!

Sure sounds like the AMM is bad and you're now in limp home mode. Runs...but only barely. You might try removing the amm and cleaning it out w/ either electronic cleaner (pricey) or brake cleaner (cheaper). If your car has LH2.4 injection, the Bosch amm model number should end in "016". Those are quite common and can be purchased for $35-50 bucks. If it is LH3.1, the amm's are a good deal scarcer and you'll pay nearly $100 or more. The O2 codes have probably been there for a while...it probably needs replacing but the run issue would be more likely amm related. Clean it gently and see if it helps...

Thank you so much for responding. I am looking online but I can't find a good picture of how to remove the AMM. Do you know of any good websites? Also...I noticed your profile says Dallas TX. I am in Dallas too. Do you have any suggestions of good places to bring a Volvo in here to get repaired if I needed to do that this week?

You have pm!

Does this car have the preheater air intake too? There's a flap in the bottom of the air box. If the thermostat thingy craps out and locks the flap on the preheater side that can kill the hot wire in the AMM. I would check that before I throw a good one in and let the same thing happen. On a warm day it should be open to the fender, and on a clod day it should be open to the preheater hose. I actually changed the flapper thing around so it's always closed to the preheated air side. I then took out the heat collector (around the down pipe of the exhaust) and the silver heater hose.

^^This. The pre-heat circuit is only used for a few minutes on extreme cold starts. Allowing the motor to idle for a minute or two negates any benefits from leaving it in place. Open air box, close the flapper to the pre-heat ed air (glue it, or drill a small hole through it and zip tie it closed). Remove corrugated aluminum heat hose and dispose of. Remove the heat collector off of exhaust down pipe.

Sorry for not responding. I had school the past couple of days, but I finally got out this evening and did what ya'll suggested. When I unplugged the AMM the car ran better (it didn't die). I don't have any brake cleaner so I'm going to run out to Autozone tomorrow and try it and keep you updated.