1992 Chrysler Le Baron Lebaron 2.5l dieing while driving

Tiny
JOEZOMBIES
  • MEMBER
  • 1992 CHRYSLER LE BARON
  • 2.5L
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 79,000 MILES
Ok bear with me cause I got a lot of info and it may get jumbled. My gf has a 1992 lebaron 4 door 2.5 liter 4cyl automatic. Her mother bought it for her claiming it was an "amazing" deal with low miles for its age. Well after a couple days of having it we realized why. The speeding would intermittently stop working. So there would be to. Es where it would work and then maybe a week straight not work, but thats besides the point. Well after a week or 2 of driving it we were noticing it was a gas hog! When I say gas hog I drive a turbocharged cobalt and tend to drive spiritedly everywhere and this thing compared to my car made me seem. Like I. Was getting Prius level fuel mileage. A week after that she was driving along and the car just died on her and would not start back up. I was out of town with a buddy so as soon. As we got back a few hours later we drove over and I tried to start it. It would crank but not start so we popped the hood and used his truck and jumper Cables and it fired right up. So I suspected a weak battery or alternator. I took out the battery and brought it into walmart and had them test it with 2 different testers and it checked fine. So I put it back in and checked it with a volt meter, it was around 12.6-12.8 volts then started the car and it jumped to 14.5 so I figure. The alternator was good as well. A few days go by and it broke down again she was on her way to work. It would t start so I come to her rescue and the thing fires right up for me. Eventually we took it to an oreilies and had it scanned and it had a code for the o2 sensor so I replaced it and unhooked the battery to reset the codes. Upon startup it seemed to actually run a like smoother and have a like. More power as well as compared to before the exhaust no longer smelled like sunburned gasoline. A couple days go by and it starts dieing on her again and wont start and gas mileage is still garbage. After it set a couple hours she went back to where it broke down and it still wouldn't start. Nearly 10 hours after it broke down I go get in it and it starts up fine. I also drove it to work. One day to give it a test and sure enough I make it a block or 2 and it just cuts out and dies while driving. I pulled over shut it off turned it back on and it cranked and cranked and wouldn't start. So I moved the shifter through the gears and back. To park and still. Wouldn't start so.I. Moved it to. Neutral and it started right up. A few days later she is driving it again and it broke down on her again while driving and she tried the thing I did with the shifter and it didn't work. Several hours later I come by and it starts right up. Help!
Wednesday, November 27th, 2013 AT 7:09 PM

7 Replies

Tiny
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The 2.5L is a really tough engine capable of unbelievable horsepower, but one real common problem is intermittent cutting out due to the Hall Effect pickup assembly in the distributor. They often become heat-sensitive and fail when they get warm, then work again an hour or two later. I never condone replacing random parts without doing a thorough diagnosis first, but in this case, since it's so common and the part is pretty inexpensive, start with that. It's a thin plastic disc with a three-wire connector, that sits under the rotor in the distributor. Any auto parts store will have it. If it doesn't solve the problem, keep the new one in the glove box for a spare.

The charging system is real easy to diagnose and repair, (with my help, of course), but since you correctly found 14.5 volts, we know that's working.

Your description of having to shift to neutral has me confused. A lot of people do not understand that "turn over" and "crank" are the same thing. They think "turn over" means to turn the ignition switch. To be clear, the engine was cranking normally but not starting. If that is correct, but it did start and run after you shifted to neutral, that was just a coincidence. If there was a no-crank condition until you shifted to neutral, that would be a starting system issue related to the neutral safety switch or the shift cable adjustment. That would be an entirely separate problem because that switch is out of the picture once you release the ignition switch. It will not cause stalling while you're driving, and it won't cause a failure to start if the starter is cranking the engine properly.

To interpret the oxygen sensor fault code, I have to know the exact code number. It's important to understand that fault codes never say to replace parts or that they're bad. They only indicate the circuit or system that needs further diagnosis. When a sensor is referenced in a fault code, it is only the cause of that code about half of the time.

Based on the readings from the O2 sensor, the Engine Computer will only modify the fuel / air mixture plus or minus about ten percent. That alone is not enough to explain the rotten fuel mileage. They used to have a lot of trouble with the MAP sensors in the early '90s. GM developed the design and had a huge problem with them, ... So they sold them to Chrysler. I'm sure yours isn't original. They all failed within the first few years, then were replaced with a better design that caused very little trouble.

The MAP sensor has the biggest say in how much fuel enters the engine, unlike all other cars. As one very high-level national trainer used to say, "Chrysler is the only manufacturer in the world that has been able to make an engine run right without a mass air flow sensor". The thing is though, there is an acceptable range of signal voltage the MAP sensor can produce, and as long as that voltage remains within that range, no fault code will be set. It can, however, report the WRONG value within that range. The computer will act on that incorrect information and command an incorrect amount of fuel. Look for a dry-rotted rubber vacuum hose going to the MAP sensor, or some other vacuum leak. Either of those will reduce the vacuum the sensor sees, which corresponds to what it would normally see during hard acceleration. You need more fuel when accelerating, and that's what the computer would command. The MAP sensor circuit can be responsible for the Engine Computer commanding more than double the correct amount of fuel needed.

MAP sensors fail very quickly when they do. The engine will go from running fine to not running at all within a day, ... Usually a few hours. They don't take many days or weeks to slowly fail completely.

Also remember that if you disconnect the battery or let it run dead, you'll erase any diagnostic fault codes stored in the Engine Computer. Chrysler makes reading those codes yourself easier than any other manufacturer. There's a link on this site to tell you how to do it, otherwise I can describe it here. If there are no related codes if the engine continues to stall, you'll need to find a scanner to view live data so you can see what is happening. Many scanners can record a few seconds of sensor data that you can replay later, if necessary. Also check for spark when the engine doesn't start. If you find that spark is missing, the next step will be to determine if the automatic shutdown (ASD) relay is turning on. I can describe that too. It's real easy, but you'll need a test light.

Finally, be aware that you caused another problem by removing the battery. The Engine Computer lost its memory and has to relearn "minimum throttle" before it will know when it must be in control of idle speed. Until that occurs, the engine may be hard to start unless you hold the accelerator pedal down 1/4", you won't get the nice idle flare-up to 1500 rpm when starting the engine, and it will tend to stall when you come to a stop, again, unless you hold the pedal down a little. It will not cause stalling while you're driving at a steady speed. Only the idle speed is too low.

To meet the conditions for the relearn to take place, drive at highway speed with the engine warmed up, then coast for at least seven seconds without touching the pedals.
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Thursday, November 28th, 2013 AT 1:15 AM
Tiny
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Ok sorry for the delay in response. Shortly after your response her car broke down again and I found the fuel line going to the fuel filter leaking so I fixed that and bought a 4 post relay to replace the was relay. The car seemed to start up and run fine idle improved gas mileage went up and everything was fine and dandy. It stopped dieing on her and was just fine. Until she loaned her car out to someone and we get it back idling a little rough under 1k rpms and started using gas again. A couple weeks go by and it died on her and will not start at all not even after sitting. Ichecked for spark and nothing. So then I pulled the distributor cap and one of the contacts was burned up and the plastic was chared around it. I replaced the distributor cap, wires, coil pickup, and rotor got it all back to together and still no spark at all. I'm at my whits end she has to have her car to make it to work this monday and idk what to do besides push it off a cliff.
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Saturday, January 4th, 2014 AT 1:24 PM
Tiny
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First be sure the rotor is turning when you crank the engine. If it's not, the timing belt is broken.

If the rotor is turning but there's no spark, by far the most common cause is a defective Hall Effect pickup assembly under the rotor. That's a disc with three wires coming out, and you said you replaced that. The next thing, which I eluded to earlier, is to verify the automatic shutdown (ASD) relay is turning on during cranking. Measure the voltage going to the positive terminal of the ignition coil, either small terminal on the back of the alternator, or the feed wire to the injector. A test light works best for this because it's easy to see and many digital voltmeters don't respond fast enough. You will see 12 volts there for one second after turning on the ignition switch. You may hear the fuel pump run for that one second too. If you don't see that voltage pulse, suspect the ASD relay or a blown fuse link wire feeding it.

Most commonly you will see that one-second pulse. What is important is that voltage must come back during cranking. If it does, all that's left is a bad ignition coil, and that isn't too common. Almost always that voltage will not come back, and that is because the Engine Computer is not turning on the ASD relay because it isn't seeing the pulses from that pickup assembly in the distributor. It's the pulses from that assembly that tell the computer the engine is rotating and it's time to turn the relay on. At this point I would suspect the new pickup assembly is defective, but first I'd check for corroded terminals in the connector, and I'd be sure there was voltage coming to it. I never had to go so far as to measure the supply voltage to the pickup assembly so I don't know if it's 8.0, 10.0, or 12.0 volts, but the point is you can't have 0 volts.
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Saturday, January 4th, 2014 AT 2:16 PM
Tiny
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I really appreciate all your help on this. I went out and bought a test light yesterday and went to work testing everything you say to and all of the said plugs checked out fine exactly as you said they should. But going to the could was nothing so I went through. Them and while checking the plug for the starter relay the asd relay clicked. I plugged everything back in and had my gf turn it over and it started right up just fine and ran just fine. I went ahead and replaced the starter, fuel system, and asd relays just for good measure. The car started and ran fine all day yesterday. She got up. For. Work. This morning and it started fine and she aren't in for a meeting for work then came out and surprise surprise it wouldn't start and she said she noticed her cars fuel. Level had dropped drastically from when she parked. It. After sitting for like 15 minutes it started up again. This car is really starting to get under my skin!
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Monday, January 6th, 2014 AT 7:01 AM
Tiny
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Don't know how to interpret this:

"But going to the could was nothing so I went through."

The ASD relay should not be clicking when you're moving things around under the hood. That implies something tricked the Engine Computer into turning it on, most likely for that first one second after the ignition switch is turned on. It's hard to believe it could be this easy without seeing it, but the 12 volt feed wire coming from the ignition switch to the Engine Computer would likely have an intermittent break in it. That break could be in the same circuit but in the wire going from the fuse box to the ignition switch. You might look for a loose or corroded fuse terminal or a corroded terminal in a relay socket. The problem is an intermittent connection would likely cause stalling once the engine is running too. Look too at the large bullet connectors in the fat wires coming off the battery positive terminal and right behind the battery.

The next thing would be to check for 12 volts at all of the feeds to the Engine Computer and see which one is missing when the no-start occurs. I have to search for a service manual to look at the wiring diagram, but for now I can offer some generalizations. There are usually three or four 12 volt feeds to the computer. One is there all the time to maintain the memory. One is there only when the ignition switch is turned on. One comes from the ASD relay to verify the computer turned that relay on. If I remember correctly, the fourth one is just for a reference for the voltage regulator and charging system and doesn't affect anything else. Chrysler was pretty consistent with the terminals they used in the 60-pin connector so I may be able to find a wiring diagram in another service manual that will be close enough.
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Monday, January 6th, 2014 AT 4:41 PM
Tiny
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Coil not could sorry about the typo I was typing this from. My cell phone.
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Tuesday, January 7th, 2014 AT 4:38 AM
Tiny
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I wouldn't know about that. I've never owned a cell phone or seen the need for one. I have enough trouble pounding two keys at once on my keyboard.
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Tuesday, January 7th, 2014 AT 2:07 PM

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