QuestionQUESTION: Hello, I recently acquired a 1992 dodge caravan with a 3.3 v6 engine. After having it about a week I was driving one day and it just cut off. It will crank but not start. I've checked all the fuses and fluids and such. I purchased a Hanes repair book for it and attempted the failure to start test. I am not seeing any spark at the coil connector. I am getting voltage to one side of the ASD relay but its not energizing. A friend told me it might be the crankshaft sensor, and i replaced it, but that didn't solve it. According to the book, i should be able to do a diagnostics test with the check engine light to produce codes for troubleshooting, but i can not get it to work. The light works, but after switching the ignition on off on of off on nothing happens. I haven't found/checked the camshaft sensor... I am getting fuel to the fuel rail, and I can hear the pump come on when I switch the key on. I sure appreciate any help you might could provide.
ANSWER: Hi Russell,
It is useful to know that the fuel pump runs, and I assume for just 1 second when you turn the key to the run position, correct? It will resume pumping when you try the starter, but usually the noise of cranking is too loud. But, if a helper will listen at the rear-side near the tank have him try to tell if the fuel pump starts up again and continues while you are running the starter. If so, then the crank and cam sensors are probably OK. If not, then I would suspect one or the other.
But you should get codes using the ignition key: do you complete the on-off...routine in less than 5 seconds? If not, then try it again. Does the check engine light remain "on". It should, but then it should begin the blinking, pause, routine. That would be very helpful to have at this juncture.
Are you certain that you are trying to tell if you have spark correctly? Tell me what you are doing. If the fuel pump doesn't run while you are cranking then indeed you also won't have spark because the two are powered by the same voltage source which is interlocked to not come "on" unless the crank/cam sensors are pulsing.
I'll await a progress report.
Roland
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QUESTION: After your reply, I went out to check if i can hear the fuel pump near the tank while a helper tried to start the van. I can not hear anything. In answer to how i am checking for spark, i am using a test light at the coil pack connector. I am turning the ignition on and checking the B terminal on the connector. the light doesn't blink. Also, i have tried the key on/off routine several times and i can not get the check engine light to stay on much less give any codes. The light is definitely working, as it comes on briefly when i turn the key to on. as I've said, I've changed the crankshaft sensor, I'm having problems locating the camshaft sensor. Also, is there a better way to check to see if the fuel pump is coming on? if it isn't then maybe the camshaft sensor is the problem?
ANSWER: Hi Russell,
I wonder if the ignition switch is bad because the check engine light is not staying 'on' when you have the key in the "run" position but the engine not running. That suggests to me that the signal to operate the light (which comes from the powertrain controller) is absent. On the fuel pump question, you could check the dark green/black wire at the fuel pump relay while you are cranking as that is the wire that goes to the fuel pump (it is the next to front relay on the left inner fender). On the ignition switch, check to see if there is voltage to fuses 14, 7, and 5 as those are supposed to get power in the "run" position. If not, then the switch is defective. The camshaft position sensor is located adjacent to the threaded end of the upper bolt of the right side engine mount. But I would try and get a solid check engine light "on" so you can get the codes before going after any more parts.
Roland
---------- FOLLOW-UP ----------
QUESTION: I tested the 3 fuses you mentioned, 14,7, and 5, with the switch in the run position. They all have voltage on both sides when switched on. I tried the check engine light test several more times, and twice i was able to get it to stay on, but after waiting 3 or 4 minutes it didn't start flashing. I also checked for voltage from the fuel pump relay. Its getting voltage to the relay (the red/wht wire) but none coming out of it, (grn/blk wire). I'm using a test light to check these but I have a voltmeter if needed.
AnswerHi Russell,
If it is going to start flashing it will do so in about 10 seconds or less. So I would suspect the engine controller (computer) but nonetheless you could replace the camshaft sensor as it is less expensive. You are certain that you are doing the entire on-off sequence (7 steps) in 5 seconds or less time? Those are my ideas.
The voltage light is ok for these purposes. You could check the wire at pin 3 red/white of the 60-way (voltage all the time) and pin 9 dark blue (when in the run position) to see if you definitely have voltage to the controller.
Roland
