A little background story:


A few month's back, my '92 developed a very strange "hesitation" problem which would show up a few seconds after the car started running - only to last a few seconds - then disappear all together.  I couldn't figure it out and needless to say, it drove me nuts.

Even though the car drove just fine after the initial stumble, I was determined to figure out what the problem was and fix even if it was just a minor annoyance. Over the next few month's, I purchased and installed a new set of Bosch III injectors.  A Walbro 255 High Performance fuel pump.  New filter and a new fuel pressure regulator.  

The problem remained. 

I then turned to the ignition system and replaced the coil and module and still no dice.  The car had new plug wires and O2 sensors put on a few month's back the same time I installed my long tube headers. I'd run out of ignition parts to replace...

Except for one that is...

From the get-go, everybody told me it was my opti-spark, but I was stubborn and didn't want to hear any of it.  I've had plenty of experience with opti-spark failures in the past with other LT1 equipped vehicles I've owned and while the "hesitation" symptom was indeed a common tell-tale sign of a bad opti, the fact that this stumble only lasted a brief few seconds only to disappear until the next day left me thinking the issue had to be something besides the opti-spark.


Well, after running out of ideas (as well as parts to replace) I bit the bullitt and went out and purchased a new Delco opti-spark.  It  occurred to me at that point, that since I had to remove the now 17 year old water pump to get to the opti-spark, I may as well buy a new pump to go along with it.  No sense in doing things half-@ssed, I always like to say.

After doing a bit of research, I decided to go with an electric water pump instead.  The Meziere HD electric pump to be exact.  I honestly didn't expect it to be worth much, (if any) horse power, but the idea of having a pump being able to circulate the same amount of coolant throughout my system regardless of the RPM I was at, I found very appealing.

The factory mechanical pump doesn't circulate coolant very well at low RPM.  My Vette has always run a bit hotter than I'm comfortable with, especially when sitting in stop-and-go traffic. Although I'm aware the LT1's were designed to run at higher temperatures, I still didn't like seeing my coolant temperature rising to 210' in traffic.  The electric pump in my opinion, would do a better job at cooling my engine during "real world" conditions (aka: stop-and-go).  If I could manage to pick up a few more horses with the electric pump, all the better, but it's not the reason I decided to go electric.

Anyways, after getting all the parts, I slowly began the project.  What was originally supposed to be a "Saturday afternoon job" ended up turning into a month long project.  Work was hectic and I'd never have enough time to get to my car.  An hour here.  A few minutes there....  It just seemed to take forever. :(

I managed to snap off a few pictures  each time I'd get a chance to work on the car and figured I'd post them up for all of you to see.  I used to always document the work I did on my car's over the years but most of the info I recorded has long been lost/deleted over the years as I went from owning one car to the next.  (I wish I still had all that info)

Hopefully, some of you can use the information in the following posts  and make use of some of the pictures  I've taken for future projects of your own.

So here goes...

Let me know if there's any interest in further updates, otherwise I'll save myself the time and keep this stuff for my self 


OPTI-SPARK & WATER PUMP INSTALL  (PART 1)












































Adams' Apple2010-05-19 10:07:50

LT1*C42009-11-08 17:41:48

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That's all the pic's I have for now.  I'll upload the rest hopefully by the weekend...

Feel free to post any comments or ask any questions about the install.

Hopefully some of you may get something out of this thread


- LT1C4  LT1*C42009-11-08 18:00:26

Reserved for final updates...

Phil, great pictures and writeup.   One of the best I've ever seen for a project we all probably will have to do someday  

Great Photos Phil.  I am still thinking about the 92

Absolutely great write-up.  My 92 has developed a high rpm miss and I know I need to swap out the opti-spark.  I've been dreading doing the job but after reading through your project and studying the pictures I ordered the parts today.  Thanks again!

hello, i was wondering does the l98 engine have the optispark i have an 1985 vette, THANK YOU

[QUOTE=msledge50]hello, i was wondering does the l98 engine have the optispark i have an 1985 vette, THANK YOU[/QUOTE]

Lucky for you, no, you're L98 does NOT have the dreaded opti

You're still using an old-school distributor.  It's much easier to access and service if anything ever goes wrong with it and it's far more reliable too due to the fact it's not as exposed to dirt, grease water/coolant like the opti-spark is.
Hope that answers your question. 
LT1*C42010-01-06 22:52:58

Yes it does answer my question and thanks alot. I had many sports cars but this is my first vette, its a 85 with 47,000 miles on it and it looks great inside and out it has the z51 package and i put the k&n filter on it with mufflers eliminators it has 3:07's in the rear, its a automatic, the air cleaner cover the middle is cut out so its open it has the original cat but i do plan to get a free flown one and i was thinking of getting a shift kit for my trans,Can you suggest some other minor mods that i can gain power just minor ones THANKS. msledge502010-01-07 16:01:29

Very nice job with all of the photo's.  I just had a shop here in GA. replace the Opti in my 96 LT-4, they put an Accel unit in as well as a new w. pump, mucho deniro, but you can't go anywhere with no spark!  Good job-Phil

Thanks Phil for the terrific write up and pictures. All of your helpful hints are invaluable

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This is great stuff.  Thanks for sharing.  I have a 93 that I know I will be replacing the opti spark soon.  When I first bought the car 3 years ago I decided to wash down the engine compartment.  Bad move on my part.  3 Days later the car started.
Anyway I also get that slight hesitation when it first starts up.  Will follow your guidelines once I get the balls to dive into the project.

Mike

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Good job and thanks for taking the time to share. The photos and description are much better than the few cryptic instructions from my factory manual.  I will have to do this job soon myself. Thanks!

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There is no problem a little horsepower can't fix!

https://www.c4vetteregistry.com/member_uploads/14301_14400/14327/100_5963_zpse01892a52014510161358r.jpg

Great write up. Should be very helpful to many. Should be a "Sticky"

Are these "Opti Spark" modules that sensitive to water? Can I power wash my engine without much concern?

[QUOTE=RonRock]Great write up. Should be very helpful to many. Should be a "Sticky"

Are these "Opti Spark" modules that sensitive to water? Can I power wash my engine without much concern?
[/QUOTE]

I put in three OPTi sparks in 12,000 miles. The last one only lasted about 1000 miles. I did away with the optispark and put in a MSD ignition. It cost me a little bit but I plan on keeping the car and driving it. It is a 94 with only 92,000 miles on it. The car has run better now than it has ever run since I had it. OK, it may not be original now, but it is not going to leave me sitting on the side of the road again. I have been sitting on the side of the road. At least a half dozen times.  I could drive it and it would just shut off. Sometimes it would crank right back up. I could try to crank it every day for 2 weeks and it would not start. The next day I go out there it starts and runs fine. The next day I get in it, it turns over and doesn’t start. That’s why I went with the MSD ignition. Got rid of that problem.

|UPDATED|12/28/2022 10:11:26 AM (AZT)|/UPDATED|


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Nice job , great photos 

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Ditch the opti-spark!!!! I put 3 on in less than 1500 miles. Found someone to replace it with a MSD ignition. Been driving it for 2 years now with no problems. The problem is the opti-spark is not vented and builds up condensation and corrodes. The MSD has a vacuum line running to it and keeps the condensation out of it. 

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Put yourself a MSD distributor in. I put 3 opti-sparks in in a 1,000 mile period. All did the same thing, they would quit, not start, some start, etc. I found someone to put the MSD ignition system on mine and it has never run better. The problem is the Opti-spark Builds up condensation And corrodes. The MSD ignition has a vacuum line running to it that keeps the moisture pulled out. That did away with my problem. I’ve driven it 10,000 miles since I had that done with no problems.

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This thread was started back in November of 2009.  Nice to see folks are still benefiting from it even tho' LT1*C4 hasn't logged into the site in over 10 years.  Too bad photos without the watermark were not posted as they would have been easier to see what was going on.

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Jim Olson