Hey guys. Need some advice here.

I bought a '95 formula a few weeks ago. First it had a problem starting right away. I'd have a crank it for a few seconds before it would fire up. But ran great there after.

Now it doesn't start at all. I pulled the coil wire off the opti and held it up against and block while cranking and I get no spark. I replaced the coil and the ignition control module and still no spark off the coil. My dealer told me it's probably the distributor. So my plan is to replace the distributor tonight unless someone has a better idea.

My ideas were either a bad ECM, crank or cam sensor. I have a good multimeter if anyone can tell me what wires to check and what kinda signals I should be looking for.

-Sean
AIM: AggieZook1k

 

I just had to check mine, turned out to be the ICM for me, but you already replaced that. Shoebox's page has the procedure, but I believe it was...

unplug the ICM harness
turn ignition to "on"
DC voltage from pin A to ground should be >10
DC voltage from pin D to ground should be >10
have someone crank the engine
AC voltage from pin B to ground while cranking should be ~2-4

If all 3 of those are right, then your opti (or at least the crank position sensor part) and PCM are fine and it's the ICM or coil. But I'm thinkin they won't be, since you've already tried a new ICM and coil.

 

Yah, looks like I'm in for the opti. I don't know why the dealer told me it was the distributor, since there isn't one. And the only cam sensor is in the opti.

So by the process of elimination, I guess it's gotta be either the ECM (not likely) or the opti (very likely).

-Sean

 

the opti is the distributor

 

If there is no fire at the coil wire, then you cannot blame your distributer. How would it work without no power. The job of the opti-spark distributer is just to disperse power to the plugs at the right time.

Check your coil or your ICM, but do not blame your opti spark until you can make sure it is actually getting power. In which case you have stated you are not.

Check your fuses also.

 

The opti also generates the hi and lo resolution signals used by the computer to determine timing and crank postion so it knows when to fire the coil. If there is no spark from the coil wire, it could be the optical sensor inside the Opti. It was in my case. Follow ShoeBox's procedure. It will lead you to the cause.

 

Well, since I've changed out the coil and ICM already, that just leaves the OPTI. I'll meter it and make sure before I put it on though.

I went to Oreilly and got an OPTI w/ lifetime warranty and without cap and rotor for 129.99. I can't imagine it being any worse quality than OEM. And atleast I won't ever have to pay for another one. That's my reasoning anyway. I could've got one from a dealer with the cap and rotor for $325, but only a 1 year warranty. Anyone think I should go that route?

-Sean

 

IMO, your best bet is to get a new GM opti for just under $200 from either:

Dal Slabaugh: 877-448-5451
email: lockitup@bright.net
VanDevere Buick/Pontiac/Olds Akron, OH

Jason Cromer: 877-726-8295 or 850-243-8826 (direct parts dept ph #)
email: gmparts@samtaylor.com
Sam Taylor Buick/Cadillac Ft. Walton Beach, FL

If you end up needing a cap and rotor, you are going to end up spending more than the GM unit.

 

If I went to the trouble to change the opti I would put a complete new one on. Check to see if you have power going to the coil. You might have gotten a bad coil.

 

Okay. I've decided to take the rebuilt one back. Now the question is: Is the dynaspark worth the $600? If it meant no more opti problems, then I'd do it. But how much better is it really?

Also, what about doing a coil-pack conversion for $800? Do you guys think the electromotive kit would make the ignition more reliable than the dynaspark?

-Sean

 

Okay well, I'm an idiot.

I guess everyone assumed I wasn't an idiot and didn't remind me to check the fuses. Turns out my ICM had been the culpret and had blown the ignition fuse. Car runs great now. Glad I check the voltages before I changed the opti.

-Sean