1994 Dodge Shadow car shuts off randonly when driving

JOAN KINGSLAND

MEMBER
1994 DODGE SHADOW
4 CYL
2WD
AUTOMATIC
16,017 MILES

I have a 1994 Dodge Shadow, I am not sure of the true mileage I have had the car for 10 years and it was used when I got it. Recently, I have had my car in the shop 3 times and they can't fine whats wrong with it. It will shut off at intersections and at drive through windows or the bank lines. They said to keep it in park when in long lines or at red lights. I have already had the oxygen censor replaced 2 times and several other parts they said I needed. I have already paid over $1800. For repairs. When I take it back each time it shuts off, they say there is nothing wrong with it. Yesterday, it shut off in a major intersection and a cop followed me back to the shop and told them it is still broken. The shop called me before they closed and said there is nothing wrong with my car. HELP PLEASE, WHATS WRONG WITH THIS CAR? Thanks Joan

8 Replies

SCOTTY DEE

MECHANIC
592 POSTS

Hi Joan! There may be a continuity problem in the power distribution center, the PCM (powertrain control module) could be flakey. Here is what must happen. First, find another shop. Second, take a technician for a ride with you and tell him/her to bring a scan tool. You drive and when the vehicle dies, say there, that's the problem I'm having and let the technician take it from there.

I wish I could give you a firm diagnosis but the conditions you describe make that difficult via email.

Scotty

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Saturday, May 22nd, 2010 AT 8:01 AM

CARADIODOC

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33,870 POSTS

Hi folks. Excuse me for butting in here in the middle of your conversation. I assume it won't restart right away until it cools down, otherwise you would simply restart it and drive away. Suspect the "Hall Effect Switch" / crankshaft position sensor. It is a disc that sits under the rotor in the distributor. It's a real common problem with a real easy fix. The additional clue is heat often makes them act up intermittently more often. When you're standing still, engine heat is not blowing away. It migrates into the sensor.

Most of the time, (but not always), there will be a diagnostic fault code memorized in the Engine Computer. If there is not, I really hate throwing random parts at an intermittent problem in hopes one will fix it, but this one is so common, the chances of it being the solution are very high.

If the problem continues to occur after the crankshaft position sensor is replaced, check for spark when it won't start. Have someone show you how to do that, or we can describe it here. We can also describe how you can read the fault code(s). It is by far the easiest to do on Chrysler products.

(I really love these tough little cars).

Caradiodoc

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Saturday, May 22nd, 2010 AT 2:43 PM

JOAN KINGSLAND

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2 POSTS

Hi Guys, Thank you for getting back to me so fast. I do not know if it's running hot, all you have to do to start it again is to push it forward about 10 feet and it will start right back up, no tiring to start it. It will start with one turn after you push it, if you don't push it you can try and start it for ever and it will not start again, I don't know why? May be it just likes to be pushed after it shuts off. Most of the time it shuts off when it is at a red light, but no matter, YOU HAVE TO PUSH IT OR IT WILL NOT START AGAIN. Thanks guys I would donate more but the garage has me broke and it's in there again, so god knows how much this trip will be. Thanks again, I will give them the information you both gave me and I want to be there when they run the fault codes on my old car. Thanks again Joan

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Saturday, May 22nd, 2010 AT 7:06 PM

CARADIODOC

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Boy, that is weird. Let me clarify something. I don't mean your engine is running TOO hot. I mean it has warmed up to normal operating temperature. That's when a lot of sensors fail.

This additional information points away from my previous suggestion about the Hall Effect Switch, but you still should check for spark provided you can keep it in the bad state long enough. Scotty Dee's suggestions might be better than mine, but that still doesn't explain why pushing the car overcomes the problem. Is it possible the engine is rocking a little and that affects a loose electrical connection?

Caradiodoc

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Saturday, May 22nd, 2010 AT 9:25 PM

TEALWHEEL

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7 POSTS

Your problem is probably what is called the Vehicle Speed Sensor (VSS), sometimes also called a Distance Sensor. It is known to cause this symptom. On some models, the speedometer will also be intermittent.

The sensor is located on the right hand output shaft of the transaxle. Sometimes the problem is just that the electrical plug to it is loose or corroded, so check that first, but I think in your case it is actually the sensor, which will have to be replaced. If I recall, it costs about $50 for the part.

Depending on the mechanic and the work environment, it should take about ten to twenty minutes to change, there's only one bolt. Be gentle with the connector so the locking clip doesn't break off, its old & will snap easily.

Good luck, hope this helps. : )

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Thursday, October 21st, 2010 AT 3:07 AM

CARADIODOC

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Hi tealwheel. Welcome to the forum. You're right on a number of counts. I replaced dozens of these speed sensors at the dealership for the speedometer staying on zero for the first two miles, and I always tightened the connector pins, but I never had one of them cause a no-start condition. I just replaced two within the last week, one on my old '88 Grand Caravan to get the cruise control working again after five years, but that one still uses a cable for the speedometer. The other one was on a like new '88 LeBaron that I repaired the digital dash on. Because of that digital unit, the car didn't use a speedometer cable. The owner said on that one too the speedometer stayed on zero for the first few miles. It had been doing that for over a year. (No wonder the car still looks like new up here in the rust belt. There's low miles on it! :) )

The older two-wire sensors use a reed switch and rotating magnet. That switch grounds out the 5.0 volt supply to it then goes open circuit as the magnet spins. There is no way that can cause a no-start because both the shorted (grounded) and open conditions are normal, BUT, ... The newer style sensor is a three-wire design and uses a Hall Effect transistor. That is a transistor that is turned on by a magnetic field instead of a small current. The signal wire still pulses between 0 and 5.0 volts but the third wire is the 5.0 volt supply to run the circuitry and that 5.0 volt supply is in common with the TPS and MAP sensor. I could imagine the 5.0 volt supply being shorted by the sensor or its wire, but that would set all kinds of fault codes as soon as the ignition switch was turned on. It still seems unlikely it would correct a no-start condition by moving the car, but I've seen other weird things the last week.

Caradiodoc

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Thursday, October 21st, 2010 AT 3:33 AM

TEALWHEEL

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Thanks for the welcome, caradiodoc! I read a few of your other posts while browsing the site before I wrote any posts and noticed you know what you're talking about and share your knowledge generously. This site is lucky to have your input.

I had to read the posts again to refresh myself about the no start. The symptom I was referring to primarily was the stall at idle at drive in windows and red lights. How that ends up being related to the distance sensor is a secret only the computer and its programmer knows, and they're not talking. : )

While Chrysler was ahead of other car companies as far as their computers went at the time, perhaps the world's most talented programmers were off doing other world shaking things. : ) I'm not really dogging Chrysler's code, but this seems to be one of the weaker spots in it.

Pushing the car a few feet would rotate the distance sensor. And it is easy to see how the computer would have a hard time deciding the sensor is bad. I'm guessing the vehicles you just changed the sensors on didn't have a code set. Mine didn't.

It has been probably two years since I fixed my car (1989 Spirit, analog electronic speedometer, no cable), and I can't recall too well, but I think my solution to the restart was just waiting.

Here's another bit of related info. I once helped a buddy (who worked at a Dodge dealer's shop at the time) repair what would have had to be an Omni or Horizon
which was failing emissions. Once again, the culprit was the distance sensor. Maybe if I think about it long enough, it will make sense as to why.

Nice talking with you, have a great day. It's lovely weather out here in the West.

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Friday, October 22nd, 2010 AT 3:07 AM

CARADIODOC

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I gots 40 degrees up here is Wisconsin and road construction season is over and road salt season is about to begin. Can't wait to get out of here!

Caradiodoc

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Friday, October 22nd, 2010 AT 3:43 AM