No spark?

[Toolman]

What would cause a no spark situation? This is on a 94, recent 60k, 150k. I have git fuel, but sometimes no spark. It has acted up a few times (dies immediately), once when I was driving (it is my fathers), but it started right back up. Yesterday, it died on him at the bank. I went over to check it out, and found that we had no spark. Took him home, got a few tools and parts, and went back. This time, it had spark and started right up. I can not find my code reader (and Ryan still has my other one, hey Ryan! ). I have not had much time to look into it, but thought I would pick the forums brain before I got my hands dirty.

 

[sdpatt]

That sounds like the crankshaft position sensor (CPS) failing and recovering. Without this sensor's signal, there is not spark and no tachometer signal. Did the tach drop to zero as soon as the spark cut out even though the engine was still turning? That would point to the CPS. There may or may not be a code set, but it would be a confirmation of the cause to read the codes. You can get the CPS through AutoZone as the Wells SU242 for $42.99.

You don't need a code reader to retrieve the error codes. All you need is a short jumper wire to connect the SIGNAL RETURN to the SELF TEST INPUT on the EEC TEST plug above the power steering pump on the firewall. Go here to learn how to perform the EEC testing and look up the codes. The links to the code descriptions are near the top of the page.

 

[Toolman]

I am lazy though. I have two readers, and the books, but just have them misplaced. It is acting like a crankshaft sensor, but it recently got replaced, along with the w/p and all 60k items. What are the symptoms of a failing camshaft sensor? I have never replaced one of those on any of the SHO's (at least not because one was bad). I do not particularly desire to replace the crank sensor so soon (but I may not have any choice )

 

[sdpatt]

The camshaft (cylinder identification, CID) sensor is used during starting to synhronize the spark with the cylinders. It won't shut the engine down when it fails, but it has been known to cause a stumble and a malfunctioning tachometer. Even though the CID is used during starting, its signal is monitored while the engine is running and will most likely set an indicative error code.

I must ask, did you gap the newly installed CPS to .03"? I may also suggest that you verify the ground path to the DIS module. A weak connection or bolting there can cause indications of both the CID and the CPS failing.

 

[Toolman]

Yes, the CPS is gapped correctly. I will be home tomorrow and I will check out the ground, and run the codes. I drove it the other day to see if I could get it to fail (because so far it had only failed for my mother, and when I showed up it started right up), and it acted like a CPS failure in that the tach went to zip lickity split. I am going to recheck all connections, and make sure this w/p is not leaking prematurely. I sure hope not. I still have 3 cars I need to tear in to, and do not want to spend any more time on this one than I have too (of course, nobody twisted my arm to get all the SHO's, so I guess I am deserving). Thanks.