QuestionQUESTION: I have 1997 Infiniti I30 that cranks but will not start.
it has injection pulse but no spark at any of the coils.
both crank sensors and cam sensor is putting out good signal.
power and ground at coil is good. can you help me?
ANSWER: Keith,
If there is no spark at the coils and the square wave generator is not defective you are looking at the ignition circuit or the ECM. I would get a Haynes Manual and use it to back track the ignition circuit. Now, the master fuses at the positive terminal are good? And, the relays have been checked? Email me back if you need more information.
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QUESTION: Thanks for the reply.
power and ground to ECM and coils are good(confirmed by running voltage drop during crank).
I have new situation though.
for some reason car starts now. sometimes requires long crank but it starts and runs well. I suspected wiring problem so I wiggled wires while it's running(I wiggled just about all the wires) but can't get it to die.
question I have now is would weak signal at cam or crank sensor(2 wire sensor) cause this problem? square wave shouldn't change with cranking speed but possible weak signal(sine wave)at 2other sensors?
ps. I have checked wires at firewall near shock tower.
ANSWER: Keith,
Check the ignition circuit at the fuse block and at the relay box under the hood. You are looking for corrosion or loose pins on the fuses or relays. And, if someone has wired into a circuit for aftermarket items. The sqauare wave generation signal strength should not vary. If it does, there is something up with the power feed. Back to checking power sources for the ignition system.
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QUESTION: I have double,triple checked power feed to ignition coil circuits. it at least have 10v at power feed wires at ign. coils during crank.
AnswerKeith,
Check the feed to the coils. If you say you have voltage then check the distributor for the presense of oil on the optical shutter wheel. Disassemble the distributor and see if there is oil on the optics. This is under the cover. You have to remove the cap, rotor, rotor post and cover to get to the optical shutter wheel. Email me back.
