Saubrenner

You Guys have heard this one before, I got my new Opti in; when I tried to start it, I got a couple of backfires but no start. I know the plug wires are on correctly, they were still marked from some previous Opti replacement. There are no codes other than 12 showing.

STL94LT1

Did the opti slide against the tming cover with little effort?

Saubrenner

It went on pretty easy, I didn't try to force it because somebody told me it should just pop on. I did wiggle it some.

TWISTERUP

Assuming it was running before the opti replacement--were you able to "seat" the new opti against the the timing cover all the way using hand pressure only ? If you used the bolts to pull the opti dist against the cover you may have forced it on wrong.The opti being installed wrong or plug wires incorrect are the first two things which come to mind.

Saubrenner

I can't imagine that I could have forced it too hard, I just don't do that. If I did, can I take it off and get a do over or is it broke?

TWISTERUP

As I said if it seated by hand and you're not Hulk Hogan --you should be ok. They can be damaged however if you use the bolts to pull the opti tight.

Saubrenner

I just pulled the #2 plug and cranked the motor, it has a good looking spark. I can still hear it trying to backfire.

pianoguy

Are you sure the opti was the problem in the first place? What were the symptoms before you replaced it?

Saubrenner

I wasn't sure but it had a code 16 and it I had only owned it a month swo I jumped to the conclusion. It originally died with my daughter driving. When I got there, it would start and run a few seconds. After a few minutes it started and I drove it home. Later that evening it started fine again to put it in the garage. Yesterday I had to move cars around to get it on the lift and it started and ran fine again. Now that I have the new opti on, it won't start at all and does have spark. I'm wondering if there is something else wrong. It's full of gas and has pressure at the fuel rail. The pump comes on when the key is turned and runs a few seconds as it should.

powerpigz-51

See if it will fire with a shot of starting fluid....

Saubrenner

I don't think that would be a good idea with the backfire it's got.

pianoguy

With all the backfiring, I thought it could be something like a slipped timing chain, but if it wasn't doing that before, that can't be it. Maybe your new opti is no good. It could be that your fuel pump or something is going, rather than anything with your old opti. Maybe take the ICM in to be tested, too.

Saubrenner

The service manual says to check the injectors next, since I have spark at the plugs. I just can't believe the injectors would suddenly go completely dead at the same time I put on the new Opti. The only way I know to be sure is pull the new one off and put the old one back on. Does anybody have any better ideas?
I still believe it's in the timing due to the back fire. I don't know how the Opti works to affect timing but if it's getting spark and fuel, timing is the only other thing.

TWISTERUP

The opti works to affect timing the same as any distributor if it is installed in the wrong position you'll have a no start and/or back fire. The opti distributor has a small "master spline" and will only go on one way correctly. I don't believe you'll find a fuel delivery or injector problem. As said before--the opti or plug wires are installed in the wrong position.

Saubrenner

Is it possible that I got the spline out time? It certainly sounds like any other small block with the distributor 180 out.

STL94LT1

It does sound like the opti splined drive is off. But, from everything I've read it would take some effort to misalign the shaft.

Saubrenner

I just looked real close at the old Opti driveshaft and saw the spline drive with the master spline. This looks to me to be the most logical thing I could have screwed up. I think I'll start over again. Is it possible that the new Opti isn't damaged and is still usable?

STL94LT1

Opti should be OK.

Once you get the opti realigned, start the car before you reinstall the water pump and refill the coolant. It won't hurt to run the car for a brief period, and it may save you from another teardown.

Saubrenner

I guess my next course of action will be to do it again and be more careful. It's going to be 1000 degrees today, so it'll take awhile. I hope to have good news tomorrow, unless I run into more problems and have ask youn's advice again.
I sure am glad you added the part about starting it with the water pump off, I was wondering that.

TWISTERUP

I guess it's possible that you didn't damage it, but IMO doubtful. I would suggest A) look very closely at both set of splines male and female for damage when you remove the new opti. B) lay both optis side by side on a flat surface and check whether or not the new opti shaft has been "pushed " into the new dist due to misalignment. C) remove the new opti cap and check visually for damage. JMO