QuestionHi Roland,
I wrote you last Monday Nov 15, about my kids 96' Cirrus not starting and the last things you had me check were the MAP sensor, temp sensor at 70 degrees and intake air temp sensor and they were all in the give specs. I told you it had spark but i wonder if its to weak? Do you have any specs for checking the rotor cap, coil and HAL effect/cam sensor ohms or voltage? I thank you for all your suggestions.
AnswerHere is our earlier Q and A:QUESTION: My kids 96' Cirrus V6 2.5L automatic #over 200,000 miles# wouldn't start one morning but ran OK until then. It will crank but won't start. Has spark, fuel at the rail, EGR valve isn't stuck, checked the mechanical timing#all marks lined up#. Changed spark plugs and wires. Tried starting fuild. Charged the battery. Ohmed the temp sensor #19k @ 50 deg F#. Pulled and swapped relays and fuses. Checked numerous connecters but still won't start. Any ideas? Thanks in advance.
ANSWER: Hi Andrew,
I suspect that either the cam sensor in the distributor or the crank sensor at the rear of the engine on the firewall side is not functioning. Use your ignition key to get a fault code that may tell you if so and which:"on-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time. Then watch the check engine light, which remains 'on', to see it begin to flash, pause, flash, etc. Count the number of flashes before each pause. Then repeat the process to be sure you have an accurate flash count. Then group the flash counts into pairs in the order that they appeared, The last pair will be 5-5, the number 55 which means end of readout. The numbers formed before that are the fault codes. An 11 means the cranks sensor is not putting out a signal, a 54 means that cam sensor is not putting out a signal. Let me know of any other codes that you get and we'll go from there.
Roland
PS Please 'rate' my answer, thanks.
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QUESTION: Hi Roland ,
The only codes it gives are 12 for battery being disconnected and 55 for end of codes.
ANSWER: Hi Andrew,
Sorry, I overlooked you said you have spark. You have spark, fuel, compression, timing, and no codes, and the egr is ok. The only other possibility I have experienced with all these characteristics is a MAP sensor that had gone inaccurate but not so badly as to set a fault code (it thought the car was at 10,000 feet rather than at sea level!). See if the MAP reads about 4.6V before you crank.
When you checked spark, I assume you did it a plug, not the coil tower, right? If not, it could be the rotor.
So other than the MAP the other possibility is the fuel pressure is way off due to a bad regulator. You might want to measure that. Mixture is probably the key to the problem if you have spark/tming/compression. Could you have a plugged catalytic converter? Do you get any sense of fuel igniting?
Roland
PS Please let me know what it turns out to be.
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QUESTION: OK Roland,
The MAP sensor wire, appears to brown with white strip, had 5.0V. Fuel pressure was 50 psi. The spark was checked at plug. Compression was good. Same codes, 12 & 55. Any suggestions? Thanks again.
Answer: Hi Andrew,
That 'violet'/white wire is the 5V supply wire. The actual signal wire is dark green/red and is on pin C at the plug or pin 36 at the pcm.
Roland
PS Thanks for the rating.
PPS That 19k ohm reading on the coolant temp sensor at 50F might be worth checking at 70F. It should be 7-13k at that higher temp which is the stated calibration point. In the absence of any other explanation I wanted you to be aware of that possible cause. Also check the intake air temp sensor resistance which has the same calibration limit.
Hi Andrew,
I don't have specs for the cap/rotor. The primary of the coil is 0.6 to 0.8 ohms, and the secondary is 12,500 to 18,000 ohms. The hall effect sensors should show an oscillation between 5.0 and 0.3V as you turn the engine by hand using crank pulley bolt and a ratchet.
I suspect those are fine because you say you are getting spark. To test the spark quality just hold an insulated handle scredriver shaft about 1/4" from the cylinder head with its tip on the spark coil tower while a helper cranks the engine. The spark should jump that spacing. Similarly you can check at one of the spark plug caps.
The rotor probably has a resistance of several 10's of K ohms but I don't know exactly what the spec is. It shouldn't be infinite, of course. The cap should be inspected for cracks.
I wonder if the egr valve might be free to move but still stuck ajar due to crud on the valve seat/valve tip? I can't think of any other reason you have spark, fuel pressure, and a reasonable MAP voltage, and still no combustion. Do you hear the injectors clicking? Do you have reasonable compression values? Does a plug show signs of fuel to corroborate that the injectors are pulsing? Those all constitute the necessary conditions for a start.
I assume as well that the spark wires are properly assigned to the sockets on the cap, which are not in the same order at the firing order due to internal rearrangements in the cap.
Roland
