5abivt

Should have read my post above you.. You could have had the damper off in 1 minute

SnAkeDr

Excellent write up! Planning to change out my optispark and water pump in the next couple of weeks. I will use this as a reference. I have a new AC/Delco water pump and a Petris OptiSpark. I'm also planning on removing the intake manifold, sending it out to get it ported, polished and painted. I also plan on sending out the harmonic balancer and having it rebuilt.

For piece of mind, I will replace all timing plate shaft seals.

Glenno

Not sure if I overlooked it but what did you do with the old water pump drive? Did you seal it off somehow? Being you used an electric water pump. Thanks

scotth48

Great write up and pictures. If replacing the water pump with another water pump instead of the electric, make sure the coupling on the shaft is put on correctly, I think the end with the groove goes towards the pump side, I don't have my book handy to confirm that.

rick146

great diy article, I'm 69 yrs with an new old 92 vert. got new plug wires and plugs for xmas. now considering changing opti and w/p at the same time sorta makes sense to me. thanks again great pics and narative.

Glenno

I'm asking about the drive shaft that used to turn the water pump? Did you remove it somehow or did you just leave it? How's the car running?

Glenno

Bumping it. How did the electric water pump get wired in? How was the old water pump drive handled? Anyone?

VetteAdictive

Great info! I plan to replace the Optispark also soon. But does the front pulley come off that easily as you say? all you have to do is the take off the 3 bolts and just tap on the pulley and it will come off without a pulley puller? Any info would be great. Thank you

Glenno

I just removed mine last week. I used a two foot long piece of 2" x 4" and a small sledge hammer. You kind of hit it with a solid thud and it will wiggle back and forth as it works it way off. Not really to difficult. I guess if it were real rusty it could be a bear?

helphos

not in my experience- i had to use a puller! I tried tapping with a hammer, etc. no luck.
Your mileage may vary, I hope!

Pradaomygada

The hardest part about removing the front balancer pulley is getting the bolts off. I placed a crowbar between the balancer and the smaller puller to keep it from turning. Once you get the bolts out turn it back and forth while trying to pull it out. It should wiggle right out.

art1953

Thanks so much for fantastic article. Getting ready to do my 92 and this is just the ticket. Just shows that a great article will always be viable.

mrodoc

Here's another thought for removing the balancer bolts. It worked fine for me. I placed a chain though the balancer and around the front cross member. I put a bolt through two of the links to make the chain tight. I was surprised at how easily the bolts broke loose. Penetrating oil on the hub/crank surface. The next evening, crawled under the car, a 2"x1"x20" piece of hardwood I had laying around, placed on hub, tap, tap, rotate, tap, tap, rotate, etc. two revolutions and it fell off.

scotth48

SnAkeDr:
I was wondering how the intake porting worked out and could you tell see any improvement with the engine. I purchased a polished intake several years ago but have not put it on yet. I was told it would be nearly as good as the Edlebrock manifold for the LT1. My goal was for better fuel economy.
Thanks.

PS your private message email was full for reply.

Scott

LT4_Vette

Of course this would be the first thing that fails on me, after 2 months of buying my first corvette! Has anybody tried buying a rebuilt AC Delco opti? I've heard that only AC Delco optis are worth getting because other ones like MSD fail after a few months or so, and also right out of the box. My 1996 has 112k miles and not sure if it has factory opti or not. Summit racing has AC Delco for $378

antfarmer2

Sac city is offering a two year warranty.

RazRacing

This how - to article was fantastic! I just used it to do my first optispark replacement and it made the job go SO much more smoothly. I bow down in your direction!

LT4_Vette

Alright so i get the idea of how the vented optispark vacuum lines are supposed to go, But it looks like the vacuum lines were all wrong. The L plug from the intake duct was not connected to the inlet on the old opti and neither was the outlet to the intake manifold. I decided to just buy a new optispark since the original one was 20 years old. The outlet vacuum line with the check valves from the opti is connected to what i think is the Vapor Canister Purge Vacuum switch. Here are some photos: https://plus.google.com/u/0/10581635...4518321/photos I disconnected the check valve cable off the Vacuum switch but it is too small to connect onto the outlet of the optispark. So im wondering if it was all wrong in the first place. Do i remove the check valve cable from the vacuum switch and get a different size hose and connect that to the outlet of the optispark? if so what would goes onto the vacuum switch where the check valve cable was before?

LT4_Vette

Alright so that top third plug connects to nothing. Wow what a waste of time, wonder how it got there in the first place. Tomorrow I will get a tube that fits onto the Opti outlet correctly and assemble it all back together.

cincycosmo

Much has been written about doing the dreaded OptiSpark replacement…most of it great information. The OP has a great guide and used this thread a lot.

Having survived my first replacement on my 1996 C4 LT1, I thought I’d dump out some notes that hopefully enhance and augment other’s instructions. I will not bother with the removal of the water pump as that is well covered elsewhere, including on ChrisFix YouTube channel as well as many others.

Starting with the harmonic balancer (ie, demonic balancer). First off, you HAVE TO remove the power steering line and gently move it out of the way. Best way to do THAT is get a crows foot wrench and a long extension(s) on a ratchet wrench. Harbor Freight is your friend...I've worked on cars and tractors for decades and never needed a crows foot wrench until this job, and doubt I'll need one again for years, so getting an affordable (cheap) set was perfect.

My harmonic balancer was stuck on really good. What worked was soaking it in PB Blaster penetrating oil for a day or so. I then bought a Lisle 51450 Harmonic Balancer puller after trying a few that would not fit in the space alloted. That specific puller is compact enough that it can be used in the less-than-generous space between the demonic balancer and the front frame rail. I modified the puller by taking the second to shortest rod and cutting it once at the 1/3 mark. Using the short piece I was able to install the puller all from above the car. Be sure and put a lot of anti-sieze on both ends of the rod. Installing the puller requires a lot of fiddling but it will work. To finally remove the pulley you have to get under the car with a ratchet and extension and crank the pulley bolt there with an assistant keeping the engine from turning over. Coat the dang demonic balancer with anti-sieze before reinstalling it so this isn't so hard the next time.

Getting the OptiSpark seal out is a trick. I again turned to Lisle (via Amazon) and got a 56920 Limited Access Seal puller. It worked great. I had a normal seal puller but it would not fit. The Lisle piece made it a snap. Getting new seal is another one of the exercises in patience but using a SMALL hammer helped me tap it in.

When I got the OptiSpark back on I test fired the engine and it sounded good. Boy, were my ears wrong that night. After reinstalling the water hoses, and refilling the coolant. I started the car up for my victory lap. As soon as I put it in gear I realized it was running on 6 cylinders. Fearing that I messed up the spark plug wires on the drivers side of the OptiSpark I used a endoscope to inspect the wires. Everything looked fine. It took me a hour to realize that I swapped two sparkplug wires on the passenger side…the EASY side to reach. Got it together after than and all is good, but when you do that test fire before the water pump is in, try putting it in gear to hear the engine under load, even if you have to lower the car off of jack stands.


Sorry for the rambling notes, but again, others have written how to guides…I’m just adding my own discoveries in the hopes that it helps someone else as much as this thread helped me.