QuestionQUESTION: I bought a 96 Sebring JXI 2.5 for my daughter that ran great and then started to die and then not restart for awhile. It died on my daughter and I had it towed to a repair shop which said it had a code for crank sensor which they replaced. It did run again but would turn on check engine light code 30 (mutltiple cylinder misfire). I changed the crank sensor again with another brand and problem seemed to go away for awhile.... It has turned on the MIL with same code, but would continue to run without problems. Now, it seems if the temperature is below 55 it will not start. I have code 300, 305 and 306. I have checked the egr valve which appears to move freely. I have read many postings and wonder what symptoms a cam sensor would exhibit? To date the following parts have been replaced: Crank sensor, fuel pump and filter, dist cap and rotor. Before I start spending money on items I don't need, any thoughts? I read a posting about the ASD relay,where is that and how do I check it?
ANSWER: Hi Jeff,
The ASD relay is in the very rear of the power box under the hood, down one level from the front of the box and a bit difficult to see. But the ASD relay would only be a suspect if when you turn the key to 'run' you don't hear a hum from the fuel pump located in the fuel tank. If it humms for about 1-2 seconds that is the normal operation of the ASD.
There are unfortunately a plethora of possible causes for a 0300 code. The factory manual suggests starting by looking at the secondary ignition circuit by means of a 'scope' which might verify an issue with the spark patterns of the cylinders. That means spending some money on labor. Another approach would be to take a look at the engine in the dark, at night when it is humid and idling to look for signs of arcing around any of the 6 spark plug wires. If so, then replace the ignition wires.
The cam sensor going out would set an 0340 code and in the process of failing it would behave very similarly to that which you experienced with the crank sensor. Unfortunately the sensor is part of the distributor which isn't sold separately from the entire unit so you have to buy at least a rebuilt unit for several hundred dollars to replace that sensor. One thing to check along that same part line would be the resistance of the primary and secondary winding of the ignition coil which are part of the distributor. If you have a digital ohm-meter these are the measurements: Measure the resistance between pin 6 of the six-pin socket of the distributor and pin 1 of the two-pin socket of the distributor and that should read 0.6 to 0.8 ohms. Then measure between the spark tower (remove the distributor cap) and ground (the - post of the battery or any metal surface of the engine block/head) and that should be 12,500 to 18,000 ohms.
After that attention might shift to the injectors but first I'd focus on evaluation of the spark wires and the coil.
Because of the temperature-dependence of the problem, you could also verify the resistance of the coolant temp sensor to be in the range of 7,000-14,000 ohm when the engine is cold. If it were much lower then the mixture would be too lean to start and idle. It is located on the horizontal water pipe onto which the coolant filler neck is mounted, next to the neck. You lift the tab to release its two-wire plug, then put your meter across the terminals of the sensor.
That is how I would suggest that you start.
Roland
Roland
---------- FOLLOW-UP ----------
QUESTION: Roland- thanks for the info. I checked the resistance of the coolant and air temperature sensors, they both seem to be in range. I had checked to see if the fuel pump cycled on when it was cold, and I could hear it run for 1-2 seconds. Of course it is a little warmer today and it started up. When it starts, it runs great, no hesitation or acceleration issues. Late last summer there were several times when it would die while she was driving or if she stopped somewhere for a few minutes it it would not restart, it would start again if it sat and cooled off. What color is the wire for the #6pin and #1pin on the distributor connectors? If I pull the distributor, is there a way to test the cam sensor? Is the cam sensor, coil or plug wires temperature sensitive? As a side note, the tach and digital odometer only work when they feel like it, but that has been that way for a long time so it does not seem related to this. I appreciate your thoughts.
AnswerHi Jeff,
That stop while driving/recover on cooling is a symptom of a failing cam or crank sensor. The wire colors of the primary coil winding are black/gray and dark green/orange, but the measurement would be made across the distributor socket pins with the plugs removed. To test the cam sensor you would measure between the tan/yellow and black/light blue wires (pins 3 and 1 of the 6 pin plug) while you turn the engine by hand with a ratchet on crank pulley bolt. You can also measure at the pcm on pins 33 and 43. You should see an alternating 5v to 0.3v pattern. That would not be present in the hot shutdown situcation, and maybe in the cold no start situation, though it seems to be a hot sensor behavior. I don't think the wires have any temperature sensitivity. The tack/odo intermittency are probably a cold solder joint on one of the pins that brings the digital input to the cluster blue plug (pins 7 or 8) where they join circuit board.
Roland
