I just got my 240 back from the mechanic yesterday, he replaced the brakes, flame trap, oil pressure switch?, and I was going to have him put a used MAF in but it was bad and wouldn't start until we put the old one back in. The car starts right up and seems to run good however the check engine light is on, the service engine light is on, and it idles really high at start up. It is an automatic and the idle goes down some after I put it in gear but it definitely seems higher than it should. The previous owners records show a new fuel pump, cleaning of the throttle body, cleaning of the MAF, new timing belt about 23,000 miles ago. She also said that her mechanic thought that the cat. convertor needed to be replaced and that the O2 sensor was bad, however the rattle from the exhaust was just a heat shield that my mechanic tightened up. My problems are that after I picked my car up yesterday and drove it home it drove fine (except for the high idle), I stopped at a store and turned the car off, it started back up and then it died out while I was driving about a minute after I left the store, I pulled over to the side of the road and let it set for about a minute and it started up again, it wouldn't start immediately after I pulled over. This is a problem that the other owner said that she sometimes had also, which I think that her mechanic tried to fix by adjusting the idle higher. I also had my mechanic put a used fuel pump relay in the car. I have tried to give as many details as possible and I am wondering what I should do next? Should I try a new MAF? I am going to look at the vacuum lines today to see how they look. Could this be the idle control valve, I have an extra one of those but I don't want to replace things that don't need to be replaced? This car has 195,000 miles on it but is in great shape and I would like to keep it. Thanks for any advice. Jay

Just an update. I checked the lines and they all seem to be fine. I unplugged the MAF and the car ran worse than before so I don't think that is bad. I put in a different idle control valve and the car is idling better, but it is still acting like it is going to stall and then it catches itself and revs up again. Today it was also bogging down when I was driving, especially if I gave it a lot of gas off a light. Could this be a bad fuel filter or possibly a sensor issue? Any advice would be greatly appreciated. Oh, the other odd thing is that the temperature gauge is really low, below 1/4 of the way up almost all of the time, and not even registering sometimes, would this cause the ECU to shut the engine off? Sorry I didn't mention this earlier. Thanks.

Check for codes, see the LH2.4 and EZ-K sections:
http://www.brickboard.com/FAQ/700-900/EngineOBDCodes.htm

after checking codes and fixing what caused them, and then reset and drive some more..

check for leaks in the exhaust system.
or blocked muffler or cat.
could cause bad backpressure that might do this.

sounds like it is not getting enough air, check air filter and box, or not enough fuel pressure, filter or pump..

like i said though, a messed up exhaust caused these problems on mine.
and it was just a separation right before the rear muffler.

also, i had one volvo that never got hotter than a 1/4 way, it never suffered from anything.
(until i hit some black ice around a corner and ran up into some cement wall!)

Hello, thanks for the responses. I talked to my mechanic and brought it back to him today. It almost didn't start this morning, had to pump the gas to get it to catch and it eventually started and ran. Started and ran the rest of the day, however the idle was revving high agian. We checked the codes and it showed bad MAF sensor, and Lambda-fuel injector problems. He thought the MAF might be because of my unplugging it. We reset the codes and started the vehicle again. This time the car revved high until he tapped idle control valve, the car then idled nicely until it stalled out. We checked the codes again and it said lambda again. I told him that the previous owner had said that it might need o2 sensor and he thought that this is the same as lambda, is this true? He told me to get a new o2 sensor and a new idle control valve and we would try that. There are a lot of price differences with o2 sensors, some are universal and some are direct fit, which ones should I get and do you guys think that this might be the solution? Thanks again.

First clean/replace fuse #4 - its possible you're not getting voltage to the heating element.

Lamda-sond is the O2 sensor.

Save some money by going with the generic replacement and splicing onto the existing wires (Bosch #13913).

Okay, I will try replacing 4 fuse, I had some of the same trouble today, this time it stalled out while I was going about 40, just all of a sudden had no power, it was running rough for a while before this but did not stall out. It started after I waited about 2 minutes and then it stalled again about 30 seconds later, waited, tapped on the idle control valve and then was able to drive all the way home. I cleaned out the idle control valve (trying to save some money) with carb cleaner, reinstalled it and it seemed to idle really well, but every once in awhile it would try to stall out and then catch itself, without completely dying. I am going to get an o2 sensor tonight and have somebody put that in tomorrow, I am wondering if this is going to be hard to install if it is spliced? One of my neighbors that works on vehicles said that he didn't think that the o2 would cause it to stall at speeds, what do you guys think? Thanks for the advice so far, this forum is great!

i don't think so either. i've never heard of that happening. but hey, there's a first time always. hope this gets fixed.

I should add that my mechanic checked spark after it stalled yesterday and it was getting spark, so that does not seem to be the issue. This is getting to be very frustrating.

Generally random stalling at speeds is usually the air mass meter, crank position sensor, or low fuel pressure. Clean/replace fuse #6 also - its for the main pump.

Listen through the fuel tank pipe to see if you're in-tank pump is running.

Check for holes in the hose between the AMM and the throttle body (where other wires/hoses make contact with it), inspect vaccum lines for leaks.

The only way to know for sure if the O2 sensor is bad is to measure the voltage on the green wire - it should swing quickly between .1 and .9 VDC.

Thanks for the advice again. Today it was idling great, almost to the point where the idle is too low and the car doesn't seem as sluggish off the start. I filled it up yesterday and put fuel injection cleaner in it to try to clean it out a little. One of the things that happened today was that it would not start without me pumping gas after I had removed the fuses 4 and 6 and then put them back in. I thought that maybe they weren't connected properly after I took them out so I foole around with them a little bit and then it started after I gave it gas while cranking, I made it home and then it started fine afterwards. I am going to put another AMM in that I bought on ebay, just waiting for it to get here. I will also check into the crank sensor, as well as pump. It seems to be hard to find the fuses for these old cars, I will have to call around tomorrow? More than one person that I have talked to think that this is the AMM, not the O2, so I will probably wait on getting a new O2 sensor until the voltage can get checked.

I had the same symptoms on my 89 740 GL and it was the AMM. This was the most frustrating thing to fix on my car ever. I really never even figured it out on purpose. Saw the problem by accident and havent had a random stall since. Just like you, I had to pump the gas pretty much to the floor to get it started sometimes. Other times it ran great. The only difference about mine was the AMM was not actually faulty, just some of the wires came loose. Hope this helps.

I should be getting a used AMM tomorrow, I will try this and see what happens. I just hope that this one isn't messed up. I will keep everybody posted on how it goes this weekend. Thanks for the help so far. By the way, if it turns out to be the crank position sensor, how difficult is it to replace this part?

Hello again, I put in a different AMM, a used one that I got on ebay, it looked pretty good so I figured I would try it first. The car started rough after I put it in, I let it idle a little bit and it sounded like it caught and began running much better. I have noticed that if the car stalls and I get out of the car and tap on the idle control valve and the AMM the car will start and run good for a while afterwards, if I don't do this it will stall out pretty fast. This has led me to believe that it is probably one or both of these things, especially the idle control valve since when I tap it the idle will fluctuate (usually going from high to low). I will probably get a new idle control valve because I think that both of my used ones are okay but will always give me issues no matter how much I clean them. After I put the different AMM in the car didn't stall out, it would sometimes hesitate while idling but it would always stay going by catching itself. I am still getting lean fuel/rich fuel codes from diagnostics. Do you guys think that this is going to be resolved with a new idle control valve?

I have an 89' 240 DL, and a year ago went thru the same problems you're having. Here's what I did: Removed in-tank fuel pump - it tested OK, replaced sock filter, replaced fuel pump relay, replaced fuel pressure regulator, replaced maf sensor. I finally found someone in my area who would diagnose the problem and it turned out to be the O2 sensor (Lambda). Replaced it and it's been fine ever since.

Interesting, a lot of people don't think that this is caused by a bad o2 sensor. I still think that I need a new idle control valve since my idle changes when I tap it. One of the funny things that has happened is that the check engine light has gone out since I just had some engine work done to fix oil leaks. I am going to check the codes this weekend to see if any different ones are present, I was getting lambda before the light went out. Thanks for the tip though, that might be my next step after I try a new idle control. Do any of you think that this could be caused by bad fuel injectors?

Hello, had the the mechanic check the voltage in o2 sensor and the voltage looked good. He said that the problem could be wires loose to the distributor. I jiggled these around a little bit when I got home to see if that might help, I will see how it runs tomorrow.

Updating previous reports. Major problems with oil leaks and transmission leaks. Over $700 later the leaks are fixed and my car is still having problems with hesitation sometimes and I am getting a 2-3-1 diagnostic code, which is running lean or rich fuel. The check engine light is off. I am wondering if the culprit could be the fuel pressure regulator. It does sound like there is an exhaust leak somewhere near the manifold, could this cause the car to stall at speed? Would like to get these problems fixed sometime soon. Also, I have just put in a remanufactured idle air control because the car was idling weird at time. Most of the problems seem to be happening when the car is warm, after driving for more than 30 minutes. Thanks for helping me try to figure this problem out.

Theres two temp sensors one for the temp gauge single wire connector and one for the ignition and fuel computer \ ECU two wire connector. It might be worth replacing the one for the ECU's this could be related to the stalling.

Update on the stalling issues. I replaced the o2 sensor, the car still had hesitation the day that I replaced it so I thought that maybe the problem wasn't fixed. It has been two days now and the hesitation is gone and no more stalling. Hopefully the problem is fixed. Thanks for all the help with this!