Help! won't start (long)

[cwang]

Hi Guys,
2 days ago a friend of mine test drove my 93 sho, and it died a few blocks away, and it won't start up again. The next morning I went there and the car started fine, so I drove home. The car dies again, while idling on my drive way, and it won't start anymore(it turns but does not start). I retrived the infamous 212 code, but the waterpump, CID, were replaced not long ago, and I could also measure the pulses coming into DIS (CID, SPOUT). The only thing I suspected was the battery, since last week the battery died, so I took the battery to autozone, they told me it was bad, put in a new one, but still won't start.
I finally decided to measure the output of DIS, I notice the outputs are really low, approximately 0.5 volts (using my oscope).
Does anybody have similar experience? I searched this forum, but do not often seem DIS fail, also since I could measure a small voltage, I assume it's probably working. Thanks in advance.
Chien
93 ATX

 

[Mr Anonymous]

Did you check the fuel pump cut-off switch in the trunk?

Are you hearing the fuel pump run before starting?

 

[cwang]

Thanks for your reply, the fuel pump runs and seems to be fine, I measured ~32psi at the rail. I could not get my tach to move while cranking, so I think there's something wrong with the ignition system.
Chien

 

[Mr Anonymous]

Did you replace the CPS (Crankshaft Position Sensor) when you did the h2o pump and the CID? No tach when cranking is generally indicative of a CPS problem, and factoring in your intermittent stalling, that sure what it sounds like to me.

 

[luigisho]

I think you may be on the right track. The CID is the cam sensor the PIP is the crank sensor. I only point this out because usually the crank -PIP-sensor is replaced with the h2o pump as they are in the same area. Either of these sensors malfunctioning can cause a no start condition. I would suspect crank sensor at first. Was it gapped .030" if it was replaced with the water pump? Faulty DIS is certainly possible, just less likely than the previous 2 sensors malfunctioning.

 

[cwang]

Thanks again,
Are there any simple test procedures to pinpoint to these failures? As I said before , I was able to measure the SPOUT and CID signals going to DIS module.
Just curious, what happens if the PIP sensor was not gapped properly(the h2o pump was replaced by a shop), would I be able to tell from simple measurements?
Chien

 

[luigisho]

Yes, you can measure it with any accurate gap measuring tool. The problem there is that you have to remove the harmonic balancer and the 3 timing covers. On the crankshaft there is a timing gear assembly. You will see the crankshaft position sensor just above it and on the assembly there are 3 shutters equally spaced that spin past the sensor. The sensor should be gapped from the bottom of the sensor .030" from the 3 shutters. It's not incredibly difficult but it will take most of a day to disassemble and reassemble all the components if you've never done it before. Most people get all of the 60k service work done in that area when going in there to avoid going back in again later.