Car will not start and/or stalls

The Lebaron name was used over many years with many different models, and different engine sizes with different ignition systems. You have to list those details when asking about an engine performance problem so I can search for the right diagrams when necessary, and so I give you the right information.

The most common model in '95 was the twin to the Plymouth Acclaim. Those came with a 2.5L four-cylinder Chrysler engine or a 3.0L V-6 Mitsubishi engine. Both use a distributor, but they have completely different ignition systems.

One thing you should be aware of first is since the battery was disconnected for other service, the Engine Computer lost its memory. Most of the sensor personalities and fuel trim data will be relearned as soon as you start driving, without you even noticing. The one notable exception is "minimum throttle". That requires a very specific set of conditions to take place, and one of them is there can't be code 24 set. We should look at that first, and if the throttle position sensor circuit is okay, the relearn procedure may take care of the stalling.

Idle speed will be much too low when minimum throttle hasn't been learned yet. The engine may not start unless you hold the accelerator pedal down 1/4". You won't get the normal idle flare-up to 1500 rpm at start-up, and it will tend to stall at stop signs. 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.

The best way to check the throttle position sensor circuit is to view the signal voltage on a scanner. The second-best way is to use your voltmeter, but that is only going to tell you the voltage being sent by the sensor, not necessarily what the Engine Computer is seeing. To start at the sensor, there's three wires going to it. For the readings to be valid, they have to be taken with the sensor plugged in. You can use a stretched-out paper clip to reach in through the weather-pack seal alongside each wire. If you need help using the voltmeter, check out this article:

https://www.2carpros.com/articles/how-to-use-a-voltmeter

If you have an older analog meter with a pointer, let me know. I can help you set it up. Also, this article shows a meter that selects the range automatically. If yours has to be set manually, set it to the20 volt DC range. That will let it read any voltage from 0.0 to 19.99 volts. You won't hurt a digital meter by using the wrong range.

Measure the voltages on the three wires with the ignition switch turned to the "run" position. The engine doesn't have to be running. You will find 5.0 volts on one wire, and 0.2 volts, (0.0 volts for all practical purposes), on the ground wire. Those two have to be right for the third one to be right. That is the middle wire. You should find roughly 0.5 to maybe 0.7 volts with the throttle closed, and it should increase smoothly with no dropouts to around 4.2 to about 4.5 volts at wide-open-throttle. If that is what you find, the code 24 may have set due to the throttle position sensor being unplugged at some point while the ignition switch was on. You can erase the code by disconnecting the negative battery cable for a minute, but then you will need to do the relearn procedure again.

Needing to relearn minimum throttle is by far the most common cause of stalling on Chrysler vehicles. The clue is the engine will always restart right away, but you may have to hold the accelerator pedal down a little. If the stalling occurs while driving, and / or the engine has to cool down for about an hour before it will restart, that is a different set of symptoms and requires a different diagnostic steps. We can tackle that if it becomes necessary.

Don't worry about the other two fault codes. Code 12 just means the battery was recently disconnected, and code 55 means the Engine Computer is done reading out the codes.

What voltage did you find on the signal wire?

To go into more detail on that circuit, if there's a break in the signal wire between the sensor and the computer, the voltage seen at the computer can "float" to some random value due to all the interconnected circuitry. As long as those random voltages remain between 0.5 and 4.5 volts, the computer will except that and try to run the engine based on those erroneous readings. To prevent that, all sensor circuits use a "pull-up" resistor or a "pull-down" resistor between the signal wire and either the regulated 5.0-volt supply or ground. Under normal operation, those resistors are so huge electrically that they have no effect on the circuit. It's like they aren't even there. It's when you have that break in the signal wire that the pull-up resistor will cause 5.0 volts to appear on the computer's terminal for, in this case, the TPS. 5.0 volts is outside the acceptable range of 0.5 to 4.5 volts, so the fault code "TPS voltage too high" is set. This is a case where you'll still measure the proper voltage sweep of roughly 0.5 to 4.5 volts at the TPS from idle to wide-open-throttle, but on a scanner the readout will show the computer is seeing 5.0 volts.

This is why I'm asking you what voltage you found at the sensor. If you have around 0.5 volts regardless of throttle position, the sensor has to be broken internally.

The other potential defects are a break in the 5.0-volt supply wire and a break in the ground wire. Both of these are less common because both of those wires are shared by other sensors. Except for short lengths of wire, a break would affect multiple sensors and you'd have multiple fault codes. If the ground wire had a break in it, you'd see 5.0 volts on all three wires at the sensor's plug. If the 5.0-volt supply wire had the break, you'd see very close to 0.0 volts on all three terminals. Either of those defects would set code 24.

I had a very unusual TPS failure on my '95 Grand Voyager a couple of years ago. It caused an elusive, and very intermittent failure to up-shift that no one could figure out over three years before I got the van. I don't expect to ever run into this type of failure again. I only found it by accident while watching the TPS voltage on a scanner, and its response didn't match what I was doing with the accelerator pedal. One used sensor and I was back on the road with no more up-shift trouble.

You don't have to special order this sensor. Chrysler is famous for having very good parts interchangeability between years and models. This TPS was used at least as far back as 1987 models through 1995 models on all engines except most of the diesel engines. You can find dozens of them in any salvage yard. As I recall, the mounting screw heads use a T20 torx socket. Be sure to use a good quality socket that fits snugly. The screws are held in with Lock-Tite so they'll be rather difficult to unscrew. I don't have good luck with a screwdriver. I use a 1/4" ratchet with a 1/4" socket, and the torx bit in that socket.

Have you tried holding the accelerator pedal down 1/4"? Which engine do you have?

Measure the signal voltage on the middle wire of the TPS with the new one installed. Tell me wat you have at idle and at wide-open-throttle. Remember, that has to be done with the connector plugged in. You may want to read the diagnostic fault codes again to see if any new codes have been set. You can go here:

https://www.2carpros.com/articles/retrieve-trouble-codes-for-chrysler-dodge-plymouth-odb1-1995-and-earlier-car-mini-van-and-light-trucks

to see the definitions, or I can interpret them for you.

Measure the voltage on the TPS signal wire. For training purposes we use 0.5 volts to 4.5 volts to describe sensor operation, but in practice you will find something close, as in 0.56 volts to 4.23 volts, for example. The exact voltages are irrelevant, but they can't get close to 0.00 or 5.0 volts. Anything outside that 0.5 to 4.5 volt range is what gets detected and sets a fault code.

You should see the voltage increase smoothly from 0.5 volts at closed throttle to 4.5 volts at wide-open-throttle. Please don't just tell me the voltages are okay. Tell me exactly what you find for the lowest and highest readings when you do that sweep. We have to be overlooking something simple of you erase the codes and code 24 keeps coming back. Also observe if it sets again immediately after it was erased or if it takes a little while for that to happen.

If you get a nice smooth sweep of roughly 0.5 volts at closed throttle to roughly 4.5 volts at wide-open-throttle, with no dropouts or glitches, the TPS is working. Once erased, if code 24 keeps coming back, the signal wire has to have a break in it. That would cause the signal voltage at the YPS to be correct while at the other end of the wire, the computer will see 5.0 volts. You can verify that by reading the TPS voltage with a scanner or with one of the better code readers that can display live sensor data.

Be aware too that by disconnecting the battery, idle speed is going to be way too low. You may have to hold the accelerator pedal down 1/4" for the engine to start Very easy solution for that when we get to that point.

Keep me updated.

Okay, now we have a basic crank/no-start condition. You'll still likely need to hold the accelerator pedal down 1/4" each time you start the engine until you have a chance to get out on the road to do the minimum throttle relearn. Holding it down further isn't the answer. In fact, if you hold it down too far, that puts it in "clear flood" mode and cuts off the injectors.

There's four possibilities. You've lost spark, you've lost fuel, you've lost both, or the timing belt has jumped. The 3.0L's ignition system has been very reliable, but if the pickup assembly fails, the Engine Computer won't turn on the automatic shutdown, (ASD) relay, then you won't have spark, injector pulses, or fuel pump. The fuel pump will still run for its initial one-second burst when the ignition switch is turned on. Listen for its hum to tell if the pump is okay.

Start by checking for spark. Here's a link to an article that describes how to do that, if it will help:

https://www.2carpros.com/articles/how-to-test-an-ignition-system

Testing fuel pressure is complicated by the fact there's no test port on the fuel rail. If you have spark but the engine still won't run, try spraying in a little starting fluid. If the engine runs well on that for a few seconds, we can assume the timing belt is okay. If you see the engine try to fire on starting fluid, but it spits out the air intake, we'll have to look closer at the timing belt. It's too early, at the mileage you listed, to suspect the timing belt. One of my 3.0L engines developed a sloppy water pump at around 280,000 miles, and since the timing belt runs around it, that was the first time the belt got replaced.

If you have no spark, use a test light or a digital voltmeter to see if the ASD relay is turning on. Look at these articles if you need help with these tools:

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

https://www.2carpros.com/articles/how-to-use-a-voltmeter

They show an "auto-ranging" voltmeter. If you have a standard meter, I can help you set it up if necessary.

You can back-probe through the wire-end of any injector's plug, but the easiest to get to is usually the ignition coil. Look for the wire that is the same color at all of those places. Most commonly it's a dark green with a black or an orange stripe. You will find 12 volts there for just one second when you turn on the ignition switch, then it will turn off. What's important is it must turn back on during engine rotation, (cranking or running). If it doesn't, the distributor is suspect. If that 12 volts is there solid during cranking, we have to look at the individual systems. The fuel pump could be dead, or less likely, the ignition coil may have failed.

You may ignore code 12. That just means the battery was disconnected recently. That code self-erases after 50 starts.