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Discussion Starter #21
Also any thoughts on ASD or Hall effect causing a problem? It's almost like something is cutting off fuel and/or spark at idle. Not sure if that would explain the miss or richness.
 

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Sensor ground is a ring tongue terminal that comes out of the harness that's on the back side of the valve cover. I think it actually bolts to the driver's side rear corner of the head. If the tropical storm doesn't hit us too soon tomorrow, I can take a picture and post it. Even if it looks intact, the strands of wire may be frayed and not making a good connection.
 

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Discussion Starter #24
Found the sensor ground. Looks to be intact. It's got a coat of oil on it along with most everything below the valve cover....but doesnt look frayed.
 

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Discussion Starter #25
Can the MAP sensor be tested with an ohm-meter as well? If so, what should the read out be at idle?
 

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The ground is a self-tapping bolt and they can easily look ok but still be not really attached, especially if it's been removed before. Oil is an insulator; I would clean that ground regardless. At worst you spend a couple of minutes.

The Hall controls the ignition and the injector pulse, so if you had an issue there, you'd be more likely to get a no start and a code. I would have that down slightly lower on my list, you're getting the MAP code that corresponds to the symptoms you would expect with that code.
 
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Discussion Starter #27
I tested the new CTS and i was getting about 8 ohms. The one on the car was pretty hard to access while still attached but I tried for quite awhile and didn't get any readout on the multimeter.
 

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The connector is a really common one on Chryslers of this age, and I'm pretty sure I've seen it in other places on other cars as well. You might consider going to a junkyard or your own bin and cutting a pigtail. That's the easiest way out.

Those pins can be a royal pain to get at, especially depending on the probes you have for your meter. The pins are rounded and the orientation makes it difficult to keep the probes on there. You could make a probe tool pretty easy, maybe a popsicle stick with a couple of strips of aluminum foil superglued to it (I would go gel style glue and shiny side up on the foil). You could use the new sensor as a template to get the spacing and width of the contacts and width of the stick right. Then run a couple of leads to a convenient location, or even extend the strips to the back of the probe (which then should be insulated with tape) for aliigator clip meter leads. You'll add a small amount of resistance by doing this but since the CTS is in kilohms you're not going to see too much error introduced.
 

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Discussion Starter #29
Update. Well as a last ditch effort I got two gallons of regular unleaded and tossed it in the tank. I had previously put a few gallons in and I figured no way had it burned through it. Also it has been premium fuel before because I didn't know any better thinking t would help with any old fuel. Well with the regular gas....a few tries and she's idling as well as these cars ever did.

However it can't be all good news....I was moving it up and down the driveway and the brake pedal went to the floor and now the brake light is on. No fluid anywhere. Is this something to do with vacuum?
 

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Update. Well as a last ditch effort I got two gallons of regular unleaded and tossed it in the tank. I had previously put a few gallons in and I figured no way had it burned through it. Also it has been premium fuel before because I didn't know any better thinking t would help with any old fuel. Well with the regular gas....a few tries and she's idling as well as these cars ever did.

However it can't be all good news....I was moving it up and down the driveway and the brake pedal went to the floor and now the brake light is on. No fluid anywhere. Is this something to do with vacuum?
No, vacuum problems would make a hard pedal.
 

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If it's full of fluid but the pedal goes to the floor the master cylinder may have failed.
 

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I tested the new CTS and i was getting about 8 ohms. The one on the car was pretty hard to access while still attached but I tried for quite awhile and didn't get any readout on the multimeter.
You don't read resistance with it plugged in, you unplug it to read it. But it sounds like you solved the problem - bad gas. I believe I called it on Friday. :)
 

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Discussion Starter #35
You don't read resistance with it plugged in, you unplug it to read it. But it sounds like you solved the problem - bad gas. I believe I called it on Friday. :)
Haha thanks Bob. It was unplugged from the connector but the metal end was still attached to the water box. Frustrating as all of this can be I am having fun learning more and more about how cars work with this one.
 

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The brake warning light is triggered by a spool valve that compares the pressure in the two hydraulic circuits (FR-RL and FL-RR). If, for whatever reason, pressure in one circuit is lower than the other, the higher pressure in the non-failed circuit is going to push the valve to one side. This movement closes a switch which triggers the light. So literally any failure in either hydraulic circuit could cause the light. I'm inclined to think that the master cylinder is probably not at fault here, since it's arguably the best protected and lubricated part of the system. Look for any sort of wetness around the brake lines, fittings especially. If that turns up nothing, take the wheels off and inspect, and pay careful attention to the rear drums. The rear wheel cylinders may be another prime suspect here. (Edit: read "no leaks anywhere" in your post above, I would definitely consider pulling the rear drums to check the cylinders for leakage. They're packed into a hot drum unlike the front calipers and the seals are already 28 years old... pushing life expired under pretty much any conditions.) Hydraulics usually work in the +1000psi range, and since the fluid stores no energy in compression, all of that pressure is lost through even the smallest of leaks. The fluid will find weak points fairly aggressively and when it does, that's it as far as that circuit goes.

It does make you think a bit about the condition of your parking brakes...
 

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Discussion Starter #37
The brake warning light is triggered by a spool valve that compares the pressure in the two hydraulic circuits (FR-RL and FL-RR). If, for whatever reason, pressure in one circuit is lower than the other, the higher pressure in the non-failed circuit is going to push the valve to one side. This movement closes a switch which triggers the light. So literally any failure in either hydraulic circuit could cause the light. I'm inclined to think that the master cylinder is probably not at fault here, since it's arguably the best protected and lubricated part of the system. Look for any sort of wetness around the brake lines, fittings especially. If that turns up nothing, take the wheels off and inspect, and pay careful attention to the rear drums. The rear wheel cylinders may be another prime suspect here. (Edit: read "no leaks anywhere" in your post above, I would definitely consider pulling the rear drums to check the cylinders for leakage. They're packed into a hot drum unlike the front calipers and the seals are already 28 years old... pushing life expired under pretty much any conditions.) Hydraulics usually work in the +1000psi range, and since the fluid stores no energy in compression, all of that pressure is lost through even the smallest of leaks. The fluid will find weak points fairly aggressively and when it does, that's it as far as that circuit goes.

It does make you think a bit about the condition of your parking brakes...
Very interesting. I'll take a thorough look tomorrow. Thanks.
 

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Discussion Starter #38
Started the car this morning...was going to check brake lines. It's showing the same symptoms as before, won't idle and dies with throttle. Probably still fuel related, just surprised as it ran so well yesterday. Probably best at this point to drain all the gas and start all new (which I believe Bob suggested a few days ago!)
 

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Haha thanks Bob. It was unplugged from the connector but the metal end was still attached to the water box. Frustrating as all of this can be I am having fun learning more and more about how cars work with this one.
Still won't be 8 ohms unless the engine is at 500 degrees or so. It's a sealed thermistor, and you should get good readings with it screwed in. About 10-15K ohms with engine cold, about 700 ohms warmed up.
 

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Discussion Starter #40
Found it. Has a very steady drip coming from the drivers side front wheel area. Good news is...she starts and idles just fine! If its not one thing it's another.....
 
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