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View Full Version : Does your new opti have play in the shaft? (I'm just about done with this opti B.S!)



mpe331lx
04-15-2010, 03:41 AM
Since day one, I have had nothing but issues with the Opti on 1hottcamaro's car.

When I first started gathering parts for the LT1 swap, I pulled the origional opti off of the motor. It had a lot of play in the shaft and the car that I pulled it from had 130K miles.

So I decide to buy an "OEM AC delco" opti off of ebay. It ends up being an all_ignition POS. It has no play in the shaft, so I put it on the car anyway. It failed with a low and high resolution pulse code within a couple thousand miles.

I put the stock one that I had laying around on it, and the rotor ended up coming apart on it (one srew was stripped/ threads ripped out)

I go out an but a true AC delco replacement opti form a local parts store. Here is the thread and quote from that thread I made about it:
http://ltxtech.com/forums/showthread.php?7096-Opti


http://i24.photobucket.com/albums/c22/mpe331lx/Fnopti.jpg

Fucking opti:hang:

Thats all


It just sucks that it is a new AC delco unit. I know it has less then 3000 miles (probably more like 1000) I'll have to check the oil change sticker (Id id an oil change the same time I did the opti).

Each opti issue/failure is pushing me closer and closer to this:
http://ltxtech.com/forums/showthread.php?t=4563

http://i24.photobucket.com/albums/c22/mpe331lx/24x_LT1_Components_LS1_Coil_per_Cyl.jpg


Im covered! I got it new from a local parts store that stocks Delphi/AC parts. I talked to them earlier today, I'm good until may of next year:peace2:

They have one in stock and I'll be picking it up monday:)


Well, the new one lasted for a very short time and shit the bed last week.

Right as I shifted into second on a WOT pull, the car just died.....I KNEW right away what happend.

I pulled the opti today and the metal tang was broken off just like the last one.

I already got a new AC opti (warranteed out), but am not going to install it yet.

Has anyone had this failure with an MSD cap and rotor?

I was contemplating breaking off the plastic nubs that retain the tang from the start and either riveting it back on or using a small screw.

I'm pretty sure the new caps and rotors on the AC units are crap over seas junk...

I double chacked to make sure that the dowel from the camshaft was not too long or bottoming out in the opti's shaft.

Both of the new AC units had just as much play in the shaft as my 130K mile opti. I had re loctited the rotor screws just to make sure there would be no issue (although it truly was not needed, they had a strong green thread locker on them already)

When I recieved my thired replacement AC opti (which also had a shitload of play in the shaft), I installed a new MSD cap and rotor. The rotor is a much better design with the metal tang being held down with a brass screw in the rear and the front part is encased/molded into the rotor.

After many runs, I thought this was the hot ticket. When one day the car started missing a little at WOT. It progressively got worse, to the point of backfiring with more then 1.2 throttle, and dropping 1-2 cyl at idle.

There were no opti related codes, so I checked out a few things on the car, but everything was pointing to the opti. I pulled it off and the first thing I did was started shaking the shit out of it..... (all the others rattled bad, due to the rotor breaking). Nothing.

I took the cap off of it and it looked ok, but I was able to see where the rotor was making some contact with the top of the cap. It just had som scrub marks, nothing major.

I pulled the rotor off and the little locating tab was broken off (but the rotor still appeared to be solidly retained by the screws). I'll try and explain this the best that I can: There retaining tabs wher the disk sits on the shafts locating tab were all crunced up, allowing the disk to move a little.

Here is a pic of one that I found off of google, and the red arrow is pointing at the area that was bent.

I luckily was able to get it warranteed out for the 4th time.:claps: But they told me " This is the last one....Thats it!":shame:

Now the new one has all the play that the others did. I just put it on the car without opening it up. I set the mallorey 685's rev limit to 4500 and am just babying it when I drive it, until I eitehr do the EFIconnection conversion, or come up with a solution that will work.

At this point I'm pretty much DEAD SET on the EFIconnection 24x kit with an LS1 PCM and coils. BYE, BYE opti.

One thing that has me thinking, Ive heard rumors that sometimes manufacturers send replacement parts that may "pass" inspection, or just meet allowable tolerances, and the better "tighter" parts go to the dealer. Has anyone ever heard of this, or have any proof to add to it.
I'm thinking about going down to the local dealer and seeing if they have one in stock, just too check the shaft play.

If I find that these ones that Ive been putting on the car are truly inferior to a dealer bought part, and I can gat one without any play on the shaft, I may take one last chance, and put another new MSD cap and rotor on one and keep my fingers crossed....

mpe331lx
04-15-2010, 03:50 AM
BTW, I checked, and double checked the cam dowel pin. It is within spec. You can also see where it enters the square hole in the opti, the mark from it only goes about halfway down in the hole and does not even come close to bottoming out.

96LT1355Z28
04-15-2010, 04:13 AM
Man sounds like you've had some crap luck! I just got an MSD opti off this site and it looks really nice. Crappy thing is I'm sure if you bought one you'd have paid enough $ in opti stuff to have just bought the efi connection kit in the first place! I don't blame you for being hesitant to put any more $ towards anything opti related!:shiner:

mpe331lx
04-15-2010, 04:38 PM
Just measured the play in the shaft: .018" WTF!

That HAS to be out of spec!

chris
04-15-2010, 05:20 PM
Wait you have .018 endplay on the camshaft ? Well if its walking back and forth its taking out the opti.

mpe331lx
04-15-2010, 09:17 PM
Wait you have .018 endplay on the camshaft ? Well if its walking back and forth its taking out the opti.


No, .018" side to side play on the opti shaft:doh:

95formula383lt1
04-15-2010, 09:53 PM
like i said on fb i have 5 optis laying out only one has absolutely no shaft play. i have no way to measure them i dont think. oo an all of them are in perfect working order.

BadBlackZee
04-15-2010, 11:35 PM
Wowzers thats some crappy luck. Opti should basically have no play in it. With .018" of play on it, the vibration will tear the rotor to pieces in high rpm. I personally have never heard of the "better quality" inspected units specifcially going to the dealer. There is no way that they would put that much effort into it. I would try and pick up another opti, maybe one from someone on here? Best of luck!

Fixxer99TA
04-17-2010, 08:42 PM
The new MSD one I bought awhile back was tight as hell. No play at all.

I wish I had a new one sitting here so I could check it for you, but chances are there is no play at all in the stock ones (when they are ok).

mpe331lx
04-17-2010, 08:52 PM
The new MSD one I bought awhile back was tight as hell. No play at all.

I wish I had a new one sitting here so I could check it for you, but chances are there is no play at all in the stock ones (when they are ok).


The sad thing is 4 new ones AC's that I've recieved form the parts store have had major play.

I stopped at two auto parts stores today and measured an AC delco: .012", and a reman : .015"

I brought home my dial indicator and am to check my origional one and the aftermarket one from all ignition.
The origional AC delco has .015" and the aftermarket one has .001" WTF!

I about to dissect my origional one and see if I can find a source for the bearing, or see if the play could be the bearing moving in the housing.

If I ABSOLUTELY KNEW that an MSD opti would cure my issues, Id buy one in a heartbeat. But I want to make sure there is nothing else causing it.

Fixxer99TA
04-17-2010, 09:13 PM
I about to dissect my origional one and see if I can find a source for the bearing, or see if the play could be the bearing moving in the housing.

If I ABSOLUTELY KNEW that an MSD opti would cure my issues, Id buy one in a heartbeat. But I want to make sure there is nothing else causing it.

Theres an idea, if you can find a good bearing to put in you should be all set. I hear you on the MSD opti thing, they are pricy and if thats not your problem... What sucks more than spending $500 bucks and not fixing anything?

As far as I remember though, the MSD bearing had NO play in it. And its been awhile since Ive had an OEM Opti in my hand, so I cant recall if there was any play right from the factory or not.

mpe331lx
04-18-2010, 05:31 PM
Theres an idea, if you can find a good bearing to put in you should be all set. I hear you on the MSD opti thing, they are pricy and if thats not your problem... What sucks more than spending $500 bucks and not fixing anything?

As far as I remember though, the MSD bearing had NO play in it. And its been awhile since Ive had an OEM Opti in my hand, so I cant recall if there was any play right from the factory or not.


I pulled apart my origional one off off the donor car last night. I verified that the play is bearing play and not the bearing moving in the housing (atleast on this one.)

I'm not sure how redily available the bearing will be. It's a stepped design (I'll take a pic later).

The other concern with replacing the bearing is that the shaft noes not have a key, so unless it is marked (I marked it) and lined up EXACTLY right when pressed back in, there is a possibility to throw the timing/phasing off.


I may pull apart the ebay opti later. The bearing on it is tight, but it allowed oil to get through the shaft area which contaminated and ruined the sensor. If it has the same sealed bearing as the stocker, I doubt the oil came through it, and it obviously didn't make it through the press fit shaft. So the only possibility was through the pocket where the bearing sits. If that turns out to be the issue, I'll seal the bearing into the case and put the OEM disk and optical sensor on it along with an MSD cap and rotor..........And I'll keep my fingers crossed at every 6800rpm upshift:laugh:

Fixxer99TA
04-20-2010, 06:48 PM
Any luck?

mpe331lx
05-10-2010, 09:56 PM
Any luck?


Well I bit the bullet and ordered an MSD Pro Billet opti today. Which i had previously refused to buy, knowing that I'd be eventually going with the 24x conversion:disagree:

But the AC delco/MSD cap & rotor combo that others have had sucess with have obviously failed me. And I'm not ready to drop the coin on the 24x conversion, a re tune, then re tune again when I build the 383.

So I figured the MSD opti will get me by for now, I can take the car off of "valet mode" (4500 rpm rev limit), and the most important thing.........we can go have fun in it:finger:

We're planning on taking the car to a local meet friday (which may have some "extra curricular activities":devil:) and then to the track next thursday (5/27)