If you didn't do anything to the timing, then I doubt you have to turn anything. It is possible that the gear on the bottom of the distributor is worn. To check this, pull off the distributor cap and rotate the rotor. There shouldn't be much play at all. If there is, you may want to consider pulling the distributor (after marking where it was) and checking the condition of the gear on the bottom.

If you do replace the distributor, you'll have to get a hold of a full feature scan tool that can display CMP Retard & do a CASE Relearn (aka crankshaft variation learn procedure) to get it setup properly.

 

You seem to know your stuff Swart, thanks for sharing.

So after my issues yesterday (chev dying in the middle of the road after a backfire, then going again after a boost but stuttering for a few mins, then working fine), and todays total lack of even starting (threw a PO108, replaced the MAP sensor, still not going, did backfire a few times), you think it could be the pickup coil?

What would be your best guess at what it might be? It seems to turn over fine, no engine error light on (nothing being read by the ODB II reader, but will anything show up with the self diagnostic?).

 

The EDI system does not have a pickup coil. There is the coil, ignition control module (ICM), cam position sensor (CMP - in the base of the distributor), and crank position sensor (CKP - located in the timing cover at approximately the 7 o'clock position when looking straight on the front of the motor.

You really have to start testing things and eliminating the possibilities. THIS SITE has a pretty good run through on testing the ignition system components.

Have you run through the entire P0108 diagnostic chart? Is P0108 still present? It is possible that the sensor wasn't the problem, but maybe wiring, or another sensor on the +5V reference from the PCM or the sensor ground (TPS, FTP, etc). Some of the sensors (like the MAP) are more sensitive than others when it comes to problems with the +5V or ground.

 

It's turning over fine, getting a cough now and again like it wants to start.

Gotta have a shower and get out there...junkyard closes in 4 hours lol.

 

Im doing the ignition test and on step 2 Im only getting 3v DC..rechecked all my stuff and still only getting 3V DC. If there was a bad ground, wouldnt it read 0?

 

Nope... the point of that test is that if it were a GOOD component and ground it would read same as if you put the test lead on the engine block.
- To doublecheck when using DVM, move the red meter lead from batt pos to engine bolt.. should read zero but in your case -probably minus 9v. That means the 'ground wire is losing 9 volts under current flow.
That's why you test this way instead of ohming it out. If you shut off power and went to ohms.. would probably read real close to zero to the block. Which would be misleading.

So now .. while the meter is reading 3v started wiggling the harness that wire goes into while watching meter. Proceed to follow harness all the way around the back of engine while watching the meter.
When reading varies you are getting closer to the problem.

Click this to see typical harness Attachment 8107
{ you guys do know to do ctrl + to zoom, right? }

Make sure these grounds are clean and tight

G102. 103, 104, 105
Make sure there's .2v or less measured between engine and chassis gnd near battery.

 

Ive noticed something that may be causing it all. The ICM is arcing from the wire going from it to the distributor.

 

Here's a video I just took :

Arcing on ICM video by nightpath - Photobucket

 

That would be the ignition coil, not the ignition control module. It could be a faulty ignition coil, coil wire, spark plug wire, spark plug, or even a distributor cap causing it to arc where it shows in the video. Looks like you're on the right track... good job, let us know what you find. I'm surprised it didn't set a misfire DTC. If you have a scan tool that will access misfire data, you'll be able to narrow the problem down very quickly & easily.

 

I tried 2 different coils, as well as 2 different wires, same result both times. Arcing fun for everyone.

Monday I'll snag a replacement distributor and another coil+wire to try.

IMO, I think the distributor is shot.