C4 Woes : Updated

I was up until 2 am last night finishing putting the car back together. All suspension back on and torqued down, lowering kit fully installed, 4 braided brake lines installed, brakes bled, new serp belt installed cause I had to cut my old one off (got stuck on something and couldn’t remove it), new coolant temp sensor installed (broke the electrical portion in the original one), new and correct plugs (at some point wrong plugs with .01 smaller gap were installed), new plug and coil wire, and re installed the driver seat after removing it to see if my aftermarket seats for the Healey would fit in.

Illustration for article titled C4 Woes : Updated
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After all that the fucking car won’t start. Cranks and cranks and cranks. I hear the fuel pump and smell unburt fuel, so not the issue. I checks all the wire routing and rechecked the coil wire, those all seem fine. Check all the fueses, those are fine. All the air sensors are plugged in and t body is working, so air doesn’t seem to be the issue.

I don’t know what I did, but I certainly feel punished by the universe. Thank you GM for making a ridiculously hard to work on 350.

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Update:

I am out of town this weekend so no proper diaging able to do other than research. The LT1 and LT4 do not have crank position sensors because the Optispark relays both cam and crank position to the ECM.

How does it work? The optical section consists of a disk with 360 slots in it, representing 360 degrees of crank rotation. A small laser/eye unit throws a beam through the disks and reads the pulses created as the slots pass through the beam. In this way, the PCM knows the precise location of the crank at all times. Spark pulses are timed through the cap/rotor side and injector pulses are also timed from this. When its working right, the optispark is an extremely accurate timing mechanism.

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Illustration for article titled C4 Woes : Updated

Now mine has already been upgraded to the MSD unit that seems to be a popular choice. There are a few other that even eliminate the whole thing and us LS coils and another style of pick up.

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So my guess is either the whole MSD Optispart died (which can cause my same failure) or there is some bad connection somewhere. I will go back over everything and pull a plug to see if there is indeed spark going to the plugs. Just when I was really excited to be driving the car with good working suspension. *sigh* I guess it is good what ever failed, failed in my driveway?

Thanks for all the ideas of things to look for. I shall update as things continue.