Does anyone know if you can safely test fire the 5.7L second-gen LT1 before installing the water pump?

I went through hell on a learning curve taking apart more than my DIY book stated to get the water pump out and replace a leaking seal on the timing cover. I want to make sure my optispark will fire without fail. The reason, I also RTV sealed the hell out of the casing and locktite the rotor screws so that I can't possibly have a future problem with this cheaper NAPA reman opti. I also discovered that the metal disk was rubbing against the sensor so I swapped positions on the disk with the lower ring and now the disk is perfectly positioned between the sensor LED readers top and bottom. This is why I am nervous that my tinkering may not work. Can anyone chime in and throw me your advice? Thank you!

 

Question answered:

https://www.corvetteforum.com/forums...-attached.html

 

yes you can...

Not sure by your description of the disc what you did but the disc is "indexed" so you want to maintain that.

If car starts you are good

 

Yes, I meant the indexed disk. I didn't know if it is supposed to be touching the bottom end top of the sensor but old GM/Buick video illustrations of the optispark show that indexed disk perfectly placed between the top and bottom of the sensor readers.

Okay, my car turns over but won't start. The problem may be that I don't have everything plugged in. My MAF is plugged in but the water pump sensor, air box temperature sensor, and my smog pump are not together on the car. I would hate to put that waterpump on and the damn thing won't start thanks to my attempt to waterproof the opti. However, a scored indexed disk isn't so hot of an idea either. What suggestions do you have?

 

UPDATE:

This car was misfiring badly when I got it up on the ramps for this optispark replacement and timing cover seal replacement. Watching some videos on youtube, the car does sound as if it is flooded. However, I need to wait for a helping hand to confirm I have spark and to try to clear out the cylinders.

 

Any backfiring?

 

No. It cranks and makes a whine sound but that is about it. The car was misfiring badly the day I hurried to get it up on my service ramps. I had the clutch replaced prior and the guy told me the ignition system was out of wack. All of that oil accumulation finally ruined the optispark.

I need to verify I have spark but I am on my own right now.

 

Op

not clear on "swapped disc to lower ring" part...Low $ aftermarket Opti is a complete crap shoot if the work either brand new or used some

The disc should be installed where it was but it should not rub inside the optical sensor. If you changed the position of the disc it likely will not start. The disc is indexed to the position of the hub. Again not clear on what you did to the disc and if you changed its mounting position

Not having those sensors plugged in should not prevent the car from starting. It may throw a MAF or intake air temp code because they are unplugged but you can clear those just by disconnecting the battery.

RTV around the OPTI...well if you felt that was necessary ... but if the optical sensor itself is bad all that RTV will do nothing

Just use a skim coat of dialectic grease next time on the large O rings that seal cap and around the rubber boot on the long opti plug

 

The non-vented and vented optisparks are different from what I researched with their internal component set-up. I will try to explain what I did again! There are two disks on the optispark shaft platform. Upon inspection of the set-up the smaller, bottom disk/ring, it looks like a possible locking ring, was twisted and when I rotated the shaft of the optispark the indexed disk was rubbing against the sensor and noticeably too close to the sensor. When I put the indexed disk on the flat portion of the shaft platform, it lined up perfectly between the sensor upper and lower LED sensors AND it locked into place on the right key of the shaft.

 

That disk HAS TO BE CENTERED in the sensor!

 

so is that smaller ring now on top of the disc?

 

Yes. The rotor screwed in just fine, I used locktite on the screws. Otherwise had I left it as it was, I would have likely experienced faulty operation. The indexed disk looked like a damn old record on a player, one side rising the other falling and slapping the sensor from the top side on the disk leaving a scratch line that would have been made worse on a running engine! If that remanufactured sensor is any good, I doubt it would have been providing any decent signal and this, I can argue, is probably why so many optis get returned to Autozone, NAPA, and what have you!

If you watch the youtube GM training video on the ABITS optispark you can see clear as day that the disk is intented to sit right on that shaft platform. Where the square cutout is, my disk actually locked into a seam on the circular key so it was meant to be put together this way! Now, I just need confirmation that my optispark is putting out sparks to my plugs, and then to get the engine to fire up.