1988 Chrysler Fifth Avenue

redhorse819

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Went shopping came out the cranked but didn't fire. Checked was getting gas, noticed vacuum transducer hose wasn't plugged to anything. lifted the air cleaner didn't see at the time where to hook to carb. put a screw in hose fired right up realized after the screw didn't do anything no vacuum source. figured later just moving the air cleaner around jarred the spark control computer. later i found the port on carb passenger side had a hose with screw in it. when bought car from cti knew they had emissions not safety the hose that plugs in under air cleaner wasn't hooked up as well. plugged all the lines back to where they went fires up no problem but still issue with stalled on turn when cold. spark control computer was replaced in 98 with mopar ordered new from cardone remanufactured question what tools do i need to replace and how is it mounted to air cleaner. the funny thing is before this happened the car ran fine no stalling ran normal even the way the vacuum hoses being the way they were. I realize converting is the way but I like to keep it the way is was thanks any help appreciated Kevin
 

Jack Meoff

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To replace the computer box with another one?

Take the air cleaner lid off and you'll see the nuts that hold it onto the air cleaner housing. They come out with a simple nut driver and the box is connected by two plugs.

You might want to just check for loose connections first. It's possible that one of the plugs has just comes loose if the box has been bouncing around a bit.
 

metallicaman0258

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^^X2

I had problems with my computer on my GF. Luckily, the members of this forum are some of the most amazing people I have ever dealt with and they got me fixed up. My computer connectors were green and corroded so i had to clean them with a pipe cleaner and some electrical contact spray. when you install your new computer, be sure to use a dab of dielectric grease on the connectors. ounce of prevention and all that.
 

redhorse819

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I want to thank everyone here for your help. I;ll disconnect negative on battery and check the connections. But I am still wondering why it was running good without the vacuum transducer being hooked up. Thanks again everyone you've been great to the response.
 

AJ/FormS

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If by vacuum transducer, you mean the little device on the end of the computer;that device controls the amount and timing of additional ignition advance, over and above the preprogramed amount.Or actually the timing cut with increased pedal/load.
I have never checked it's base timing program, so I cannot say what it might be, but it seems it must at least have a reasonable power-timing curve, for you to feel that it was running good without it.
Keep in mind that the vacuum supply line may be compromised or hooked up wrong or not at all;on the OTHER end.Or the device itself could have a perforated diaphragm, in which case,it would make no difference to the computer at all if it was hooked up or not, except the engine would see it as a vacuum leak.And it would be getting lousy fuel mileage. And finally, someone may have reset the distributor, in an effort to increase the base timing, which the computer would have no way of knowing about. This cheater-timing usually leads to pinging under part-throttle application.
IIRC there is a very specific way to set the base timing, which, I have forgotten.I seem to remember it involved disconnecting a certain wire.
To check the transducer operation, you simply apply a vacuum to it and if the idle speed changes, it is working. If it does not change, you may have a defeat sw on the curb idle screw. Simply stick a piece of paper between the screw and the switch ground, and try again.I usually just suck on the hose and if it holds vacuum I assume it's good to go.
The vacuum supply line has a specific routing. It may not go directly to a vacuum source. There is supposed to be a hose routing diagram affixed to the underside of the hood that details the routing.The supply hose may be routed thru a number of devices before it gets to the source vacuum.Of course each of those devices would need to be checked for proper operation.

FWIW; none of this is related to your no-fire condition.
 
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redhorse819

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thank you for the info iam going to try cleaning the connections and pins with suggestions from the great people on this site and yourself. if it runs good without transducer ill put the hose with the screw back in the carb port.I'm not sure where the vacuum transducer hose plugs in. so i pluged it in the carb. it ran fine the way it was before the no fiiring. I read on the internet that mopar had problems with the lean burn system or spark control computer. I figured with the oem 18 year spark control computer that was the problem. so i bought a remanufactured cardone spark control cross reference to the oem r4289813. I believe the replies to corroded conections clean it up I also read on the internet you need to wear a ground strap so you don't creat static electricity which can damge the computer. Sounds like wearing a ground strap when yu replace hard drives in a computer everything works well back to autozone get my money back I looked at the vacuum diagram on the hood it doesn't show where to hook the vacuum transducer Thank you for your help again
 

Justwondering

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So you are talking about the part with the vacuum line coming from in in this picture -- the top yellow arrow..
IMG_3962-witharrows.jpg
 

Justwondering

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redhors819 - do you still need to know where the line goes to after it leaves the vacuum transducer?
 

redhorse819

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redhors819 - do you still need to know where the line goes to after it leaves the vacuum transducer?
is it the passenger side of the carb someone put a small hose with a screw in it. the vacuum transducer diaphram must be bad because it runs better without it hooked to the carb. thanks for your help
 

redhorse819

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thanks metallicaman on your suggestion used electric contact cleaner pipe cleaner and dielectric grease They were clean and the plugs where tight. stilled cleaned it and added dielectric grease to the conectors the vacuum transducer is bad that's why who owned the car before me bypassed it. just in case I'll hold onto the new spark control computer. If the spark control is faulty least I will have one to replace it Thanks again to all you mopar enthusiest.
i missed the 70's when I owned a bronze black vinyl 1968 440 dodge charger least they were easy to work on.bought it in kansas came homeon leave got stopped by the police not for speeding but for they didn't see a car like that in Massachusetts I always enjoyed my mopars Thanks again everyone you gus have been excellent.
 
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