QuestionQUESTION: 56K miles, seldom driven last 4 years, new timing belt, fuel pump, filter, tank, plugs, wires, cap, rotor. No power to coil at run key position. Can hear fuel pump turn on for 1 second when key turned. Disconnecting/reconnecting 10 wire plug at spark control computer will energize coil, injectors breifly. What do I do next to remedy this?
ANSWER: Hi Donald,
In '84 the only way to get a fault code readout was via a 6-pin plug in the engine compartment near the left strut tower using a Chrysler DRB-I or equivalent Snap-on, etc. device. But my suspicion is that one or other of the two sensors in the distributor has gone bad. Everything you describe is normal except for no spark and the most like cause is that distributor sensor module. The coil of course could be bad. Check the primary winding of the coil to see if it is in the range of 1.3-1.5 ohms, and the tower to the + or - post of the coil should read 9-12k ohms.
You could measure the pulsing from the sensors to see if they show signal when you turn the engine by hand via a wrench on the crank pulley bolt, and with the ignition switch in the run position. You will find there are two 3-wire connectors at the distributor. You would measure the voltage between the black/light blue wire of each plug and either the tan/yellow wire or the gray wire (depending upon which harness plug you were checking out). You should see the voltage oscillate between about 5v and 0.3v as you turn the engine by hand, doing that pulsing several time per revolution if a specific sensor is good. You can do the measurement by using fine straight pins to probe throgh the insulation of the wires to reach the conductors inside, then attach the leads of the voltmeter to the pins. I believe that if one of the sensors is bad you will have to replace the hall-effect module which contain both sensore.
If you find a code reader the fault codes for the two sensors are 11 and 54. But either way I suspect you will find one of the sensors to be bad which then causes there to be no spark.
Roland
PS Please 'rate' my answer. Thanks
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QUESTION: I did pull codes 12 and 33 via the on/off/on/off/on keying for the power limiter flashing codes. The car does not have A/C. Any chance the auto shut down relay might be involved? The car ws recently running when a bad noise came from the fuel pump. Hence the new fuel parts, but no start since. Thanks.
ANSWER: Hi Donald,
Thanks for the info that the power loss light will also give the codes in a pre-'87 vehicle, the manual doesn't mention that possibiity!
I don't see there to be an asd relay in the circuit. Its function appears to be done by the power module for the spark coil and injectors, and the logic module for the fuel pump. You could verify at the - post of the spark coil to see if you get 12v on the dark green wire when cranking as a test of the asd function of that module. If you do, then maybe you should verify the fuel pressure level when cranking it over or listen for the pump while cranking, and also verify that you are getting spark from the coil when cranking.
Roland
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QUESTION: My 84 FWD Mopar manual wiring schematic shows an ASD for the non turbo, and a fuel pump relay for the turbo, which symbolically appear to be the same. Anyhow, I found only 8.5 volts at cavity one of the distributor plug. Also, no continuity between cavity one of distributor, and cavity 3 of the 10 way spark control computer plug.I'll still do other checks, but I thought I'd mention these findings. Thanks
AnswerHi Donald,
Thanks for pointing out the 'fuel pump' relay in the turbo which is really an ASD relay. I missed it.
That voltage at the distributor is supposed to be around 8V so that is normal. My diagrams don't mention 'cavity numbers' for the distributor plugs, just wire colors and alpha numberics but if you have no continuity where you think it should be, then that would explain no signal.
I'l await further progress report.
Roland
