co5j

my daughters car died saturday night. road trip to check on it, no luck so towed it home. 2.5 V6, cranks fine but wont start. you can hear fuel pump whir when you turn key to on. doesnt appear to have spark testing at #2 plug wire, no spark at all. took distributor completely out to check primary and secondary coil, both ohmed to specs. plugs, wires, cap and rotor less than year old and look fine. re-installed dist, used haynes manual to check voltage to and from cam sensor, both good. checked voltage to crank sensor, good, checked FROM crank sensor, should fluctuate between .3-5volts, got a steady half volt or so. changed crank sensor ($65.00!), actually had different resistance readings than old one so i was hopeful, STILL only half volt when cranking according to procedure in manual. read that i should check ASD relay by checking voltage at #1 fuse because it has to pass voltage by there if ASD is good and that has voltage. at a loss, really doesnt seem to be getting spark but other than PCM, i've checked everything else. only thing i cant get is voltage FROM crank sensor, or so it seems anyway. frustrated now so havent put plug wires back on dist after changing/testing crank sensor. what would keep me from getting 5 volts fluctuation on crank sensor wires?

Airjer_

These are well known for coils going bad in the distributors. With the cap off use a test light with the lead to ground an put it right in the coil "tube thingy". Watch carefully as somebody cranks it over. If there is the faintest hint of spark replace the coil/distributor.

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co5j

i thought i had effectively checked the coil by checking the resistance readings which were .7 and about 15K, both mid-range limits. am i wrong to expect the .3-5V fluctuation at the crank sensor wires like the book says? the cam sensor seemed to do that so i expected to see the same thing.

co5j

i have determined that i have a steady 10.5 volts at the single distributor wire but not 12. will that keep it from getting spark and if so, what could cause the voltage drop?

Airjer_

Dark green/orange - power from ASD relay. Is it ten volts all the time or when cranking? what is battery voltage key on engine off and while cranking.

That wire splices off and also supplies power to the upstream heated O2 sensors, the alternator, injectors, ASD input at the PCM, and theoretically the downstream O2 heater via fuse one in the PDC.

If you have 10.5 volts while cranking the battery may be getting low and that is what battery voltage is also if this is the case there is not a problem. If battery voltage is higher than something is drawing it down or there is some added resitance in the wire somewhere AKA corrosion?

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co5j

i was thinking battery drainage too at first, so i was jumping from another vehicle and still had a steady 10.5 volts at the single distributor wire, 13+ volts at the battery while jumping. is 10.5 volts enough to produce spark and if so, does the fact that i have that much there eliminate things like the crank sensor and PCM? could the distributor still be bad even though all resistance readings are good and cap and rotor are relatively new? thanks for any help or ideas, very frustrating and i need to get my daughter back into her car, she's trying real hard to finish college.