QuestionHello again Roland,
After your last posting I tried your suggestions. I found that there was no voltage on the “T” plug that goes to the coil. I measure one ohm of resistance between the 2 contacts. After trying these measurements, I checked the engine codes again. Now I receive three different codes. 12, 41 and 25.
Ed
AnswerHi Ed,
If there is no voltage on the 'upright' of the "T" WHEN YOU ARE CRANKING then there is either something wrong with the ASD relay, the control of that relay by the engine controller, or the voltage supply to the relay. But the strange thing is that you said you hear the fuel pump run for a second when you first turn the ignition switch to run (which is normal) and the injectors click when you are cranking it (which is normal) and both of those use the same 12V supply from the ASD relay as does the spark coil.
So check again to see whether you get 12V to the upright for 1 second when you turn the ignition switch to run or not. You might also check the wires to the ASD relay socket if you can get to the wires underneath the relay socket with the relay still in place? The ASD relay is the next to the inboard-most one in the distribution center under the hood.
It should click and then release after 1 second when you turn the ignition key to run position and 12v should always be present on the forward-most pin (#27) and when it clicks it should provide 12v to the pin on the opposite side (#29) for one second (dark green/orange wire). Then when you start cranking the relay will close and put 12v on #29 for as long as you crank and that should show up on the upright of the "T" socket which is also the dark green/orange. If none of this happens then either the timing belt is broken (the rotor in the distributor won't turn when you crank it), the sensor in the distributor is bad (but either of those would cause a 11 or 54 code, neither of which do you have) or the ASD relay if it clicks has bad internal contact points so the voltage is not being connected across it from 27 to 29. You will have to try to measure what is going on to cause there to be no voltage at the upright of the T when you crank it. Without the 12v to the coil you can't get spark.
I wouldn't worry about the 25 (automatic idle motor) until you start getting spark again, and the 41 may be related to the no 12v to the spark coil because that same wire is needed for the alternator to operate (which is what the 41 code is saying has a problem). Have you checked fuse between pins 40-41 (20 amp) in the power distribution center? It supplies the 12v to pin 27 of the ASD relay. So if that were blown that would explain the missing voltage.
I will leave you now to pursue these possibilities.
Roland
P.S. When/if you write back, please do so as a 'follow-up' to this response so that the whole history is preserved for reference.
Question
Hi Roland,
I wrote for your advice a week or so ago on my 93 Lebaron which has a 3 liter V6. I did as you recomended and what I found was that when I turn the key I do hear what I beleive is the fuel pump as well as a click sound that you sugested that would be the injectors. I did find that there is no spark. I checked all conections and cleaned the contacts on the inside of the distribitor. I am open to any other sugestions before I start replacing hundreds of dollars of parts.
Thanks again.
Ed
Answer
Hi Ed,
You didn't tell me where you checked for spark: at the center wire of the distributor cap, at the spark plug proper?
I would recheck to be sure that you don't have any codes other than 12. Then I would pull the 2-wire plug on the spark coil and measure for the presence of 12V on the vertical or 'upright' of the 2-contact "T" shaped plug when you are cranking the engine, just to be sure that the ASD is providing power to the coil on the dark green/orange wire.
If you are getting that 12V when cranking then either the driver for the spark that comes from the controller to the cross bar of the "T" or the coil itself is bad. Check the coil: Measure the resistance between the two contacts at coil's plug socket and verify that it is 0.97 to 1.18 ohms. Then I would measure the resistance from the center electrode socket to the body of the coil to verify that it reads 11,000 to 15,300 ohms. Then I would plug the 2-wire connector into its socket and remove the center wire from the distributor cap and hold it's tip 1/4" from the cylinder head while a helper cranks the engine. See if you get spark. If not then there has to be something wrong with either the sensors in the distributor (which should produce a code 11 or 54 if so) or the engine controller. If you do get spark, but you don't get spark from the plugs themselves, then check the rotor (resistance from center button to tip) and the distributor cap (arc traces or cracks).
Finally I would remove the distributor cap and make sure that when a helper cranks the engine that the rotor is rotating.
So I'll await results of all these tests to figure out why no spark. No need to 'throw' parts at the problem, just analyze.
Roland
Ed Smith Asks in Category Chrysler Repair ...
Subject: '93 3.0L V-6, stopped with no codes, won't fire up
Private: no
Question: Hello,
My 93 labaron quit running yesterday as if it ran out of gas. I read your advice to another question stating to check the codes the the "check Engine" light would display. The only code I can generate is 12.
Thank you
Answer: Hi Ed,
Without codes we have find out if you have spark and fuel. Here is how I answered a very similar question earlier this year for the same engine:
"When you say "checked spark to the coil" do you mean that you checked the 12V supply to the spark coil + post when cranking it for 5 seconds, or do you mean that you tested for actual spark at the end of the spark cable that enters the distributor cap by holding its tip 1/4" from the cylinder head while a helper cranked it for 5 seconds or did you check the spark at one of the spark plug caps using an inserted screwdriver with its shaft held 1/4" from the head? Which you did would be relevant for me to know. I would prefer that you verified spark using the screwdriver shaft held 1/4" from the block as this proves spark at the plug proper, or you can remove a plug and then insert it back in the cap and hold the threads against the block while cranking and watch for spark to jump the plug gap.
Do you hear the fuel pump run for a second or so when you turn the ignition to the run position?
Do you hear the injectors make any clicking sounds when you are cranking the engine?
All those would help clarify if we have timing signals and that the ASD relay is closed when cranking...
So if we have compression and spark and fuel that is properly synchronized, we get into some of the more subtle issues like mixture (MAP/coolant temp sensor/fuel pressure) and throttle position sensor and idle control motor any of which could be off value but not so far as to set a fault code. There are tests for all those which I can fill you in about. But if you would be willing to focus on the above items and let me know if one of them resolves the problem and if not then we can approach the subtle ones.
If I am maxed out write me back by the comments section of the "thank and rate" tab below. I only take one question at a time so it isn't so easy to find me available. Otherwise I get overwhelmed.
P.S. If you have a car that has an egr valve then the valve might be stuck ajar and prevent a mixture necessary to start and idle the engine. See if you can spot the valve between the rear exhaust manifold and the intake manifold near the throttle body."
So try to test some of those same items (spark, fuel pump hum, injector click, does it have an egr), Ed, and let me know what you find.
Roland
