Engine will not start

Please be sure I am reading this right. You have a no crank condition, meaning the starter does not spin the engine. Why did you replace the crankshaft position sensor? That implies the starter is working okay but the engine will not run.

If this is a no crank problem, do you hear a light click from the starter relay when you turn the ignition switch to "crank"? Do you hear a single, rather loud clunk from the starter? If you do not hear anything, what happens to the brightness of the head lights or interior lights when you try to crank the engine?

So the engine does turn, hence my confusion. It sounds like you are describing a simple case of forgetting to remove the crankshaft position sensor before working on the clutch. I am not sure why replacing the flywheel is necessary. There are differences in the numbers and locations of the notches in the ring around it that are detected by the sensor. Those pertain to different years and engine sizes which is why some people run into unexpected problems when they change their engines and use one from a different year. As long as you keep the original flywheel/torque converter, there will not be a problem.

It sounds like you are looking at a crankshaft position sensor for a different engine. Here is a photo of what yours looks like. I looked at applications two years older and two years newer, and other engine sizes, all for Dakotas, and there is no other sensor style shown. I have seen what you described with just one mounting hole, but those were typically found on front-wheel-drive cars and minivans.

I am just going by the information from my research, and from memory. Is there a reason you need to replace the flywheel?

Those are not really relevant to our story. My minivan has an 18 gallon gas tank, and I can get 20 gallons in it without having to shake the van to settle the gas.

I am not aware of any changes. What was the problem? Was it just a crank no start or was the sensor being hit and broken by the ring on the flywheel?

I cannot argue against what you were told, but I find it hard to believe Chrysler would come up with a new sensor design and expect everyone to buy a new flywheel. That goes against Chrysler's corporate culture since the 1930's where they put customers' best interest ahead of profits. According to a group of national-level instructors, they still have the highest "customer-friendly business practices", after Hyundai and Toyota. We will not discuss the bigger manufacturers that are at the bottom of that list.

As a point of interest, Chrysler only makes about twenty percent of their own parts, not including sensors. Those are contracted out to independent suppliers. Chrysler tells them the specifications the part must meet. It is real common to go to the dealer's parts department and find the part you need has been "superseded" by a new part number. We have no way of knowing what changes they made for reliability or to address a common problem, but the new part number is supposed to replace the old part, rarely with any modifications. The only exception I can think of is the camshaft position sensor on some four-cylinder engines. They had a sensor for a different application already in production, and it was a better replacement for the problem-causing sensor, except the plug was a little different. From then on, that sensor came with a new plug to splice into the harness, if necessary.

Given all of your story up to this point, it is safe to assume the no-start is related to only the crankshaft position sensor. The way I would approach this now is to connect a scanner to view the signals from that sensor and the camshaft position sensor. I have a Chrysler DRB3 scanner for all of my vehicles. With an extra plug-in card, those were able to do emissions-related stuff on all brands of cars and light trucks sold in the U.S. Starting with 1996 models, so a lot of independent repair shops bought them. By 2004 they started to become obsolete, and the last model year they worked on was the 2008 Jeeps. Because of that, the shops had to buy something else to work on the newer models, and those newer scanners also usually work on the older vehicles. That means the DRB3's do not get used much anymore, and you can find them on eBay. In fact, since the dealer I used to work for still likes me, they sold me four of those scanners years ago. I sold three on eBay to pay for the one I kept.

To address the needs of my newer truck, I just bought a Snapon Solus Edge, also from eBay, but here is where you might be able to score a good deal. Snapon charges shops $1,000.00 per year to upgrade the software to the latest version, but here is one of those "customer-unfriendly business practices". If that scanner is only updated to 2014 models, you are required to buy the 2015 update, (for $1,000.00), before you can buy the 2016 update, (for another $1,000.00), so you can buy the 2017 update. This scanner only costs $3,900.00 new with the latest 2018 updates, so it's silly to try to upgrade the older scanners. For this reason, you will find a lot of them on eBay for less than $900.00, and they are good for up to 2012, and maybe 2014 models. If it covers all the year vehicles you want to use it on, you do not ever have to buy any updates. Just use it as is. This way they do not have any value to repair shops and you will find them to be very inexpensive. If you are going to be working on your own vehicles in the future, you will be amazed to see what you can do with a scanner that you never knew you could do.

To color the story a little, I am chasing an elusive problem on my 1994 Grand Voyager, and since I have my DRB3 borrowed out to a friend, I wanted to use the new Solus Edge, but for 1995 and older vehicles, it requires a different cable, and a Chrysler connector adapter which I do not have. I am suspecting I have a failing crankshaft position sensor, and I want to view the signal status on a scanner, but so far I do not know how that would be displayed on the newer scanner. If you can find a shop with a DRB3, the two sensors are on a long list of "Inputs/Outputs", and they are shown as "Present" or "No", during cranking and/or running. This will tell you instantly if a signal is showing up from the crankshaft position sensor. Be aware you could have absolutely nothing wrong with your crankshaft position sensor or its signal. There are other things that can cause the symptoms you have. Without a scanner, you have no way of knowing what is missing.

For the next part of my wondrous story, be aware the air gap for that sensor is critical. The older design was adjustable by means of a thick paper spacer glued to the end of it. You were to push the sensor in as far as it would go, at which point it was hitting the ring on the flywheel or torque converter. As soon as you cranked the engine for the next time, that spacer slid off and was discarded, but at that point its job was done. If you ever needed to remove that sensor and reinstall it, you were to stick a new spacer on the end. A lot of aftermarket replacement sensors had a thin plastic rib molded to the end to set that air gap. Once the engine was running, that rib would typically wear down a little, so when that style needed to be removed and reinstalled, you were supposed to cut the rib off, then stick on the paper spacer.

With your sensor design, no adjustment, (no misadjustment), is possible, which leads me to believe that air gap is not quite as critical.

Assuming there is no signal showing up from the crankshaft position sensor, here is a list of things I can think of that could cause the problem: First would be a wiring problem. With the ignition switch on, one of the three wires must have a supply voltage coming from the engine computer. Typically that is 5.0 volts, but it could be 8.0 volts, 10 volts, or even possibly 12.0 volts. That voltage will not be there and be wrong, so the exact voltage you find is not what is in question. The question is, do you have it or do you not? If it is there, check the ground wire next. That is shared with other sensors and that wire goes to ground through the engine computer so it can be monitored. For that reason, you will find it is at 0.2 volts. If you have both of those, the third wire is for the signal, and when that is developed varies depending on the design of the sensor. Most of these are magnetic, and they detect interruptions in their magnetic fields created as a hole in the ring on the flywheel moves past the sensor's magnet. When these have internal circuitry in them to amplify those tiny electrical pulses, you can often see the signal voltage change from something real low to something close to the supply voltage when you slowly rotate the crankshaft by hand. This is the signal the computer is looking for when it changes to "Present" while cranking.

Some of these sensors develop their signal voltage simply by their magnetic field being disturbed, but there is no amplifying circuitry inside them. Those almost always use only two wires. One of the critical variables with this design is speed. The faster the ring with its notches moves past the magnet, the higher the signal voltage will be developed. That voltage has to reach a certain value before the computer can read it. You will never be able to rotate the crankshaft fast enough by hand. In fact, many of these do not even develop a useful signal until the engine has started running on some other sensor(s) first.

The next variable is that air gap. If that is wrong, I suspect you would see an erratic "Present" or "No" on the scanner during cranking. Since we are dealing with some unknowns here, I would entertain a notion to learn more about the air gap you have. First pull the sensor out and be sure it did not get broken from hitting the tone ring. If that did happen, that has to be the wrong sensor for that application. Next I would stick a little grease on the end, about 1/8" thick, and a piece of paper over it so the grease does not stick to the tone ring. Push the sensor in all the way, then pull it out and look at how much that grease compressed. The air gap on the older sensor design was about 1/16". I would expect to see the same thing on yours. If you have to repeat this with a thicker glob of grease, the air gap is too big and the sensor cannot be expected to generate a usable signal. Look for excessive rust or dirt buildup on the flywheel housing that is holding the mounting bracket up too far.

The next thing that makes me nervous is the new flywheel. Chrysler has always been famous for real good parts interchangeability, but when it comes to these flywheels, while they all bolt on the same, it is those notches that have to be right. I am not aware of any publication that lists what is needed for each year and engine size. I only know to replace it with one that has identical notches. For V-6 engines, there will be three groups of notches. Typically there will be four notches in each group. With this design, the computer only know when a cylinder is coming up on top dead center. It needs the signal from the camshaft position sensor to know which piston is coming up on its compression stroke, and it relies on the distributor to send the spark voltage to the correct cylinder.

On some V-6 engines, two groups of notches still have four notches in each group, but the third one has only three notches. With this design, the computer can tell by counting the signal pulses, which pair of pistons is coming up on top dead center. These engines usually use a single ignition coil to fire those two cylinders at the same time, and there is no distributor. One cylinder fires on the compression stroke, and the mating cylinder fires on the exhaust stroke. That is referred to as "waste spark". This is where you can get the wrong flywheel/flex plate with the wrong groups of notches. When the computer is programmed to count four pulses, four pulses, and four pulses, per crankshaft revolution, if it sees four, four, then three pulses, it gets confused and will wait for that last fourth pulse. Basically, the computer has to be matched to the tone ring. This is where when people swap in an engine from a different year, and they keep the flex plate from the replacement engine, it is wrong and they have a crank/no-start.

I just realized I am using the terms "flex plate", "flywheel", "torque converter", and "tone ring" to say the same thing. I am sorry if that has led to any confusion. What I am referring to is that metal ring with the square holes in it.

One thing I would like you to set my mind at ease is to listen if you can hear the hum of the fuel pump for one second when you turn on the ignition switch. If you cannot tell, take a test light and back-probe the wire at one of the fuel injectors. Typically that will be a dark green/orange wire. It is the wire that is the same color at every injector. You should see the test light turn on for one second. If you do not, we have some other problem to diagnose. If it does, just out of curiosity, see if it turns back on during cranking. Here again, if it does, there is some other problem. The computer turns on this entire circuit when it sees signal pulses from the crankshaft position sensor and the camshaft position sensor.

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Looking at the part numbers and the pictures I see they show one sensor part number #56027273 for manual transmissions and a different part number #56027272 for automatics. They look identical in the pictures except for a small connector alignment tab inside the shell. Might be grasping at straws but it may be that it is the automatic sensor and not the manual? I would not think the connectors would go together but have seen stranger things happen.

Have you had any luck getting your vehicle running?