[John Wood]

This is a repeat of a suggestion made by another poster, either on your previous post or on another persons.:

You need to monitor the DC signal lines using a voltmeter or ideally a storage scope. Look at the 5 volt reference and the 8 volt reference signals. Use the minimopar resource page to help identify the locations and color of the wires.
http://minimopar.knizefamily.net/ecu/lm-1986-t1.html

I would guess that you have a voltage line shorting to ground which is dragging the voltage near zero. It is an intermittant short that is affected by heat or vibration. You could also have a fusible link that is barely and intermittantly making connection to the wiring harness, resulting in an open connection.

Expect to get bombarded with a lot of suggestions but check each one out logically and don't jump to conclusions.

Even if someone had the exact same symptoms, it does not mean that their solution will be your solution. You need to find out what is killing the fuel control and then try to figure out where the problem is.

Since the MAP sensor has a BIG influence on fuel delivery (i.e. mixture) I would start by monitoring the reference signal line to it. You could even unplug it to see if the vehicle will start and continue to run.

There is some possibility, based on your description, that the problem may be occuring as you transition from open loop to closed loop. The closed loop (fully warmed up) condition is very much dependent on a number of sensors.

 

[Guest]

This is a repeat of a suggestion made by another poster, either on your previous post or on another persons.:

You need to monitor the DC signal lines using a voltmeter or ideally a storage scope. Look at the 5 volt reference and the 8 volt reference signals. Use the minimopar resource page to help identify the locations and color of the wires.
http://minimopar.kni...lm-1986-t1.html

I would guess that you have a voltage line shorting to ground which is dragging the voltage near zero. It is an intermittant short that is affected by heat or vibration. You could also have a fusible link that is barely and intermittantly making connection to the wiring harness, resulting in an open connection.

Expect to get bombarded with a lot of suggestions but check each one out logically and don't jump to conclusions.

Even if someone had the exact same symptoms, it does not mean that their solution will be your solution. You need to find out what is killing the fuel control and then try to figure out where the problem is.

Since the MAP sensor has a BIG influence on fuel delivery (i.e. mixture) I would start by monitoring the reference signal line to it. You could even unplug it to see if the vehicle will start and continue to run.

There is some possibility, based on your description, that the problem may be occuring as you transition from open loop to closed loop. The closed loop (fully warmed up) condition is very much dependent on a number of sensors.

Guess What? One person on this forum mentioned to me that if one fuel injector is failing that the other three would not function right. I'm still trying to get a picture in my mind why that could be if it is true. I found out today that my fuel injector for cylinder #2 was getting too much fuel. I noticed this before in the past; but I blew that thought off that it would cause my car to not start up at times and die on me like I was getting no fuel. I was getting too much fuel in cylinder #2 . I air blasted the excessive fuel out of the #2 spark plug and inspected the other #1 #3 and #4 spark plugs and they were not fouling out.

I reinstalled #2 spark plug, then I tried to start the car again and it almost started; but died again.

I pulled the #2 spark plug out again and it was fuel fouled/flooded like it was the first time I checked it. I ordered a complete brand new set of 4 fuel injectors and will install them and hopefully that will fix the problem I have been having. I know that the #2 injector is bad so I have to take the next step and install the new ones before anything else. Weird! because my mind says if you have three other injectors to supply fuel to the other three combustion chambers, then it should at least fire up and run, even though it would run rough. It did from time to time; but of course not long and the same problem was there. I'll sit back now and analyze how this could be as I was told that all must be working to not die out on me. It's funny how just one fuel fouled plug would act like the car wasn't getting any fuel.

I hope this will fix the entire problem I have been going through. Well! at least, I'll have one more problem solved to go to the next if need be.

 

[John Wood]

Guess What? One person on this forum mentioned to me that if one fuel injector is failing that the other three would not function right. I'm still trying to get a picture in my mind why that could be if it is true. I found out today that my fuel injector for cylinder #2 was getting too much fuel. I noticed this before in the past; but I blew that thought off that it would cause my car to not start up at times and die on me like I was getting no fuel. I was getting too much fuel in cylinder #2 . I air blasted the excessive fuel out of the #2 spark plug and inspected the other #1 #3 and #4 spark plugs and they were not fouling out.

I reinstalled #2 spark plug, then I tried to start the car again and it almost started; but died again.

I pulled the #2 spark plug out again and it was fuel fouled/flooded like it was the first time I checked it. I ordered a complete brand new set of 4 fuel injectors and will install them and hopefully that will fix the problem I have been having. I know that the #2 injector is bad so I have to take the next step and install the new ones before anything else. Weird! because my mind says if you have three other injectors to supply fuel to the other three combustion chambers, then it should at least fire up and run, even though it would run rough. It did from time to time; but of course not long and the same problem was there. I'll sit back now and analyze how this could be as I was told that all must be working to not die out on me. It's funny how just one fuel fouled plug would act like the car wasn't getting any fuel.

I hope this will fix the entire problem I have been going through. Well! at least, I'll have one more problem solved to go to the next if need be.

It is certainly possible since these are batch fired (1&2 and 3&4). If there is a short on one injector, it will prevent the other from firing. It would be tough for the engine to just run on 2 cylinders.

Be sure to let us know what happens.

 

[Bob ONeill]

I thought it was the evens then the odds. Thanks for clearing that up for me John.

 

[Bob Lincoln]

"May" prevent it from firing. You don't know what the drivers are capable of. They might put out enough current to overcome a short. But that doesn't seem like what's happening here.

 

[ccgriffith]

Hmm, (kind of off-topic) does anyone else believe that vehicles have their own personalities & minds? I'm not one to usually personify a non-living object, but machines of all sorts (I've noticed at least) tend to have their own mojo. Maybe it's just my over-active imagination giving ungrounded reasoning to coincidental happenings.

My wife's Jeep likes to spit the Check Engine light ONLY when I'm driving it (I only drive it at most 10% of the time).
When my daughter would be in my truck (while it was carb'd), the suspension/ride would loosen up, and it would idle & drive much smoother, with some extra oomph to it, too.

The same goes for the machines I've dealt with at the factories I've worked at over the years.

SeattleLion, maybe your car just doesn't like you?

On a more serious note, I'm banking on an electrical issue. I know you said you checked all the electrical work, but even the hard-to-see, hard-to-reach places, too? In the end, I'd have to guess its the Logic (if it isn't the Injectors), but I don't want to believe a 2 year old part is to blame. But, I've seen newer parts fail, too, so who knows.

 

[Wizard]

1. What sensor is OEM what is aftermarket and where it is came from, There are some that is no good.

2. Have you even resorted to unwrapping completely on injector harness? Pete (95Spirit) lost his engine to bad harness. Ditto to harness for sensors. And there were corrsion/electrical issues where water leaked into logic module via harness.

3. Contacts, contacts... Have you look real closely to make sure they are tight? The weather-proof connectors give you false sense of tightness due to seals yet the contact is all flabby. I have been caught by these many time in electronics of all kinds not just in vehicles.

4. Logic and power modules are they from *reputable* rebuilder? Not all is good. If you can, tell us where you got them from?

Cheers, Wizard

 

[Guest]

Still after one year I haven't solved the problem with my 1986 Chrysler New Yorker 2.2L Turbo and all the tests show good. I let the car set for one year and started it back up about a couple of months ago and it ran for almost an hour. I drove it up and down the road several times and no problems and than it died again after one hour of running. Then I had starting problems after an hour of running and once I got it started again it died on me in a short period of time on several occasions so I parked it again. This is strange and a pain in the [I should have my mouth washed out with soap for using such terms] trying to figure out why this vehicle won't stay running. When it is running it runs great on the most part other than some slight irratic missing on idle and I replace the Idle Air Control on it also; but it has always had a slight irratic miss on idle since I bought and drove this vehicle for over 8 years. Problem is i can't keep the darn thing running all. Read all the comments in this post because I did everything people here were telling me to do and there shows no problems showing up in the diagnostics of this vehicle. I was thinking, can the ignition switch play a role in this where it will die on me? It acts like it isn't getting fuel; but I put a fuel pressure gauge on it and it was at a steady 55lbs and didn't leak down after it sat with the engine shut off. I also have a new pressure regulator on it and fuel pump. All ignition is working. I know 3 things and engine needs to start and run are Air/Fuel, Ignition and Timing and that all shows good so WTF could it be that is causing thie engine to keep dieing on me? It only has about 10,000 miles on this engine I rebuilt so it is not in the engine either and I have had wore out engines in the past that would keep on running.

 

[John Wood]

Are you the original poster (under a different name)? or can we assume this is the first time we have heard of this problem?

Of course there are a number of things that can cause the engine to mysteriously die. A common one on that era of engine is the distributor pickup. For some reason they become intermittant, but it could always be something else like just a bad connection.

 

[Guest]

Are you the original poster (under a different name)? or can we assume this is the first time we have heard of this problem?

Of course there are a number of things that can cause the engine to mysteriously die. A common one on that era of engine is the distributor pickup. For some reason they become intermittant, but it could always be something else like just a bad connection.

This is the same username I been using since I registered. I have replaced the distributor ignition module and also tried another new one from the Autoparts store in case the new one I bought was bad. I have done a modulation test on them all and they all show working correctly.

Are you the original poster (under a different name)? or can we assume this is the first time we have heard of this problem?

Of course there are a number of things that can cause the engine to mysteriously die. A common one on that era of engine is the distributor pickup. For some reason they become intermittant, but it could always be something else like just a bad connection.

I posted a lot on this problem in the past. i did everything mentioned in all the replies and still have the same issue.

 

[John Wood]

I skimmed through all the posts from the beginning of the thread. We need to try and figure out if it is dying because of incorrect fuel pressure or if it is an ignition problem.

Do you have a fuel pressure gauge that can connected up? I think the MFI cars have a test valve on the fuel rail. It would be great if you could monitor the fuel pressure when it is acting up.

 

[Guest]

I already tested the fuel pressure. It is 55lbs and that is the call out for the 2.2L engine for my car. The fuel pump is new from a dealer, not an aftermarket. All four fuel injectors are new, Runs flawlessly when it runs as you accelerate; but still it dies randomly whether to are on idle or accelerate. fast and snappy throttle response. When it does start to die sometimes when I pump the gas pedal to accelerate at a higher rpm it will take off again but not for long and dies out again like it's not getting fuel, but it is getting fuel because the pressure gauge stays at 55LBS. I'll also do a quick test as soon as it dies using a test light on the negative side of the coil and it gets nice and bright pulsations so the ignition system is working properly. I have done wiggle tests om all the wiring and nothing causes it to die. I removed all the wiring harness protection and looked at every wire for signs of over heating or weak areas in the insulation and it all looks good. I check for corrosion at the terminal ends attaching to the new Logic module and new Power module and they are good to go. I have adjusted the timing in every piston nearest to top dead center also and it doesn't solve the problem. I have checked the timing cog gear settings and they are right on the mark per factory specifications. All vacuum lines are good. No leaks. New Idle Air Control Valve Checked ERG Valve. Good, Replaced all the sensors just because they all had over 200,000 miles on them after I rebuilt the engine. Engine only has 10,000 on it now. Nobody yet can figure this one out.

 

[John Wood]

This is definitely a difficult problem to diagnose. Thinking about all the tests you have performed confirming fuel pressure and spark, the only thing that comes to mind is something related to firing the injectors. Assuming there is a solid 12 volt positive voltage on each injector (hot side) with the engine running, the computer selectively grounds each injector momentarily via a timed ground pulse to open it and release fuel. Naturally the pulse length determines the amount of fuel released. Both the Logic module and the Power module work together to determine when and how long the injectors will fire. Review the minimopar.net resource page; ECU section, to see the pinouts for both the logic and power modules.

If there is an intermittant connection at either of the modules or the wiring between the modules is intermittant, or one of the modules is bad, or you have an intermittant ground,.... then one of those that might be the cause of the problem.

It is probably going to take a scope to really see what is going on here.

 

[Guest]

This is definitely a difficult problem to diagnose. Thinking about all the tests you have performed confirming fuel pressure and spark, the only thing that comes to mind is something related to firing the injectors. Assuming there is a solid 12 volt positive voltage on each injector (hot side) with the engine running, the computer selectively grounds each injector momentarily via a timed ground pulse to open it and release fuel. Naturally the pulse length determines the amount of fuel released. Both the Logic module and the Power module work together to determine when and how long the injectors will fire. Review the minimopar.net resource page; ECU section, to see the pinouts for both the logic and power modules.

If there is an intermittant connection at either of the modules or the wiring between the modules is intermittant, or one of the modules is bad, or you have an intermittant ground,.... then one of those that might be the cause of the problem.

It is probably going to take a scope to really see what is going on here.

I'm going to have to agree with you about using a scope. I have to save up the money and buy one. I don't take my vehicles to shops anymore after my first car issue in the past I was having troubles solving. I have been an automotive technician for over 25 years working on all makes, models and years; but this doesn't mean I have all the answers. I always learn something new or something I just didn't think about under stress. Any time I could not figure something out that took a long time to do was with only two cars I have owned in my life, one was a 1973 Caprice. I gave 4 shops including a dealer a stab at it with my Caprice and ended up spending over $1000.00 dollars and they never could figure it out. I finally was told by an old timer to block off the return line and if it worked to leave it blocked off unless I wanted to spend time to drop the fuel tank and replace the return valve., They just replaced parts I told them were new and tested and not to replace them; but to look at their fuel line diagram to what I may have missed checking. I bet it would cost me over $2000.00 dollars and none of these shops would figure it out either trying to diagnose my 1986 Chrysler New Yorker with the 2.2L with Turbo engine and they would most likely start replacing parts and not fix it. I'll buy my own scope that I been thinking I should have. I can't trust shops at all.

 

[Bob Lincoln]

Hall effect pickup. Same symptoms on my turbo.

I have a handheld Velleman scope, HPS-40 or something like that. It was $279 and works great, has jpg video capture as well as memory. A newer offering has USB download instead of the serial port on mine.

 

[Guest]

Hall effect pickup. Same symptoms on my turbo.

I have a handheld Velleman scope, HPS-40 or something like that. It was $279 and works great, has jpg video capture as well as memory. A newer offering has USB download instead of the serial port on mine.

I have a new hall effect pick up in it and I also tried another new one just in case the new one I bought was bad. It didn't fix the problem and the shaft has to play in it either. I'll check out online this scope model you posted. Thank you.

 

[Bob Lincoln]

How many miles on the dist cap, wires and ignition rotor? They char quickly. I replace the rotor every 15K miles, and cap and wires every 30K miles. At 15k miles, I remove the wires from the cap, turn the prongs 180 degrees and use the backside of them. I had a no-start at 20K miles once when I left the rotor maintenance for too long.

 

[Guest]

How many miles on the dist cap, wires and ignition rotor? They char quickly. I replace the rotor every 15K miles, and cap and wires every 30K miles. At 15k miles, I remove the wires from the cap, turn the prongs 180 degrees and use the backside of them. I had a no-start at 20K miles once when I left the rotor maintenance for too long.

All brand new wires, spark plugs, cap and rotor. Same problem was occurring with the older wires spark plugs cap an rotor and they only had 10,000 miles on them. Every part on that engine is new and rplaced the Logic Module and Power Module twice just to see if any of them were defective. Not the problem

 

[Guest]

This is definitely a difficult problem to diagnose. Thinking about all the tests you have performed confirming fuel pressure and spark, the only thing that comes to mind is something related to firing the injectors. Assuming there is a solid 12 volt positive voltage on each injector (hot side) with the engine running, the computer selectively grounds each injector momentarily via a timed ground pulse to open it and release fuel. Naturally the pulse length determines the amount of fuel released. Both the Logic module and the Power module work together to determine when and how long the injectors will fire. Review the minimopar.net resource page; ECU section, to see the pinouts for both the logic and power modules.

If there is an intermittant connection at either of the modules or the wiring between the modules is intermittant, or one of the modules is bad, or you have an intermittant ground,.... then one of those that might be the cause of the problem.

It is probably going to take a scope to really see what is going on here.

I have a question for you.This is about my 1986 Chrysler New Yorker 2.2L with turbo. I was talking with my father last night and he told me one of the members at his masonic lodge said he had a Chrysler New Yorker with the same symptoms mine is having. I asked my father what year did he have and my father said he did not know. The man told my father he took it to a shop and they found out it was a fuel heater causing a vapor lock. I looked at some fuel system diagrams for my year of automobile but never saw anything like that. That doesn't mean it doesn't exist. Do you know of a fuel heater inline somewhere on this fuel system possibly? One thing to mention here also is that when the car dies the fuel pressure was still at 55Lbs. Wouldn't a vapor lock change the pressure reading? That was my first thought about this new information told to me about that mans Chrysler New Yorker shop diagnostic and fix on the issue of it vapor locking due to a faulty fuel heater.

All brand new wires, spark plugs, cap and rotor. Same problem was occurring with the older wires spark plugs cap an rotor and they only had 10,000 miles on them. Every part on that engine is new and rplaced the Logic Module and Power Module twice just to see if any of them were defective. Not the problem

I have a question for you.This is about my 1986 Chrysler New Yorker 2.2L with turbo. I was talking with my father last night and he told me one of the members at his masonic lodge said he had a Chrysler New Yorker with the same symptoms mine is having. I asked my father what year did he have and my father said he did not know. The man told my father he took it to a shop and they found out it was a fuel heater causing a vapor lock. I looked at some fuel system diagrams for my year of automobile but never saw anything like that. That doesn't mean it doesn't exist. Do you know of a fuel heater inline somewhere on this fuel system possibly? One thing to mention here also is that when the car dies the fuel pressure was still at 55Lbs. Wouldn't a vapor lock change the pressure reading? That was my first thought about this new information told to me about that mans Chrysler New Yorker shop diagnostic and fix on the issue of it vapor locking due to a faulty fuel heater.

How many miles on the dist cap, wires and ignition rotor? They char quickly. I replace the rotor every 15K miles, and cap and wires every 30K miles. At 15k miles, I remove the wires from the cap, turn the prongs 180 degrees and use the backside of them. I had a no-start at 20K miles once when I left the rotor maintenance for too long.

I have a question for you.This is about my 1986 Chrysler New Yorker 2.2L with turbo. I was talking with my father last night and he told me one of the members at his masonic lodge said he had a Chrysler New Yorker with the same symptoms mine is having. I asked my father what year did he have and my father said he did not know. The man told my father he took it to a shop and they found out it was a fuel heater causing a vapor lock. I looked at some fuel system diagrams for my year of automobile but never saw anything like that. That doesn't mean it doesn't exist. Do you know of a fuel heater inline somewhere on this fuel system possibly? One thing to mention here also is that when the car dies the fuel pressure was still at 55Lbs. Wouldn't a vapor lock change the pressure reading? That was my first thought about this new information told to me about that mans Chrysler New Yorker shop diagnostic and fix on the issue of it vapor locking due to a faulty fuel heater.

This is definitely a difficult problem to diagnose. Thinking about all the tests you have performed confirming fuel pressure and spark, the only thing that comes to mind is something related to firing the injectors. Assuming there is a solid 12 volt positive voltage on each injector (hot side) with the engine running, the computer selectively grounds each injector momentarily via a timed ground pulse to open it and release fuel. Naturally the pulse length determines the amount of fuel released. Both the Logic module and the Power module work together to determine when and how long the injectors will fire. Review the minimopar.net resource page; ECU section, to see the pinouts for both the logic and power modules.

If there is an intermittant connection at either of the modules or the wiring between the modules is intermittant, or one of the modules is bad, or you have an intermittant ground,.... then one of those that might be the cause of the problem.

It is probably going to take a scope to really see what is going on here.

I have a question for you.This is about my 1986 Chrysler New Yorker 2.2L with turbo. I was talking with my father last night and he told me one of the members at his masonic lodge said he had a Chrysler New Yorker with the same symptoms mine is having. I asked my father what year did he have and my father said he did not know. The man told my father he took it to a shop and they found out it was a fuel heater causing a vapor lock. I looked at some fuel system diagrams for my year of automobile but never saw anything like that. That doesn't mean it doesn't exist. Do you know of a fuel heater inline somewhere on this fuel system possibly? One thing to mention here also is that when the car dies the fuel pressure was still at 55Lbs. Wouldn't a vapor lock change the pressure reading? That was my first thought about this new information told to me about that mans Chrysler New Yorker shop diagnostic and fix on the issue of it vapor locking due to a faulty fuel heater.

I thought it was the evens then the odds. Thanks for clearing that up for me John.

I have a question for you.This is about my 1986 Chrysler New Yorker 2.2L with turbo. I was talking with my father last night and he told me one of the members at his masonic lodge said he had a Chrysler New Yorker with the same symptoms mine is having. I asked my father what year did he have and my father said he did not know. The man told my father he took it to a shop and they found out it was a fuel heater causing a vapor lock. I looked at some fuel system diagrams for my year of automobile but never saw anything like that. That doesn't mean it doesn't exist. Do you know of a fuel heater inline somewhere on this fuel system possibly? One thing to mention here also is that when the car dies the fuel pressure was still at 55Lbs. Wouldn't a vapor lock change the pressure reading? That was my first thought about this new information told to me about that mans Chrysler New Yorker shop diagnostic and fix on the issue of it vapor locking due to a faulty fuel heater.