C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette
Sponsored by:
Sponsored by:

I'm Back! It's Time...

Thread Tools
 
Search this Thread
 
Old Jun 7, 2020 | 09:22 PM
  #21  
derekderek's Avatar
derekderek
Race Director
 
Joined: Jul 2015
Posts: 13,082
Likes: 3,399
From: SW Florida.
Default

I did a little Google research today. Tried optispark repair. Every single thing I found you were repairing the optispark by taking it off and throwing it away and putting something else on instead or another new optispark. Pretty resourceful bunch here. Somebody would have found a way to take it apart and put a $35 part in it and put it back together running if it was doable. I don't think it is.
Reply
Old Jun 7, 2020 | 10:57 PM
  #22  
nyciti's Avatar
nyciti
Burning Brakes
Photogenic
Photoriffic
Liked
Top Answer: 1
 
Joined: Aug 2016
Posts: 1,000
Likes: 283
From: New York
Default

Originally Posted by derekderek
I did a little Google research today. Tried optispark repair. Every single thing I found you were repairing the optispark by taking it off and throwing it away and putting something else on instead or another new optispark. Pretty resourceful bunch here. Somebody would have found a way to take it apart and put a $35 part in it and put it back together running if it was doable. I don't think it is.
They use to sell them but most folks could never get them to seal and the rebuild would almost fail asap so they stopped making them pretty quickly.
Reply
Old Jun 8, 2020 | 12:46 PM
  #23  
Stumpdeisel's Avatar
Stumpdeisel
Thread Starter
Racer
20 Year Member
Conversation Starter
All Eyes On Me
Liked
 
Joined: Dec 2004
Posts: 416
Likes: 11
From: Merrick NY
Default

Originally Posted by OldCarBum
American Auto Wire just came out with a new C3 complete wiring harness for restomods.
New blade type fuses and upgraded for high amp alternators and other nice features.
It will plug into all your oem equipment or it can be ordered to use with other upgraded gauges etc.
I just received mine and it is a very nice harness.
For the electric headlight conversion, p.m. Richard454 for his “complete” conversion kit.
I recently purchased his kit and it is top quality and dealing with Richard was great.
It is the best one offered on the market.
Thanks for the head's up OldCarBum.

I looked up this kit, and agree it appears to be top notch, but twice the cost of painless? Not sure it's worth the extra 620 bucks...

1968-1976 Corvette Classic Update Kit


$1,199.00
PART #:
510717

https://www.americanautowire.com/sho...sic-update-kit
Reply
Old Jun 8, 2020 | 06:17 PM
  #24  
derekderek's Avatar
derekderek
Race Director
 
Joined: Jul 2015
Posts: 13,082
Likes: 3,399
From: SW Florida.
Default

https://www.ebay.com/itm/Ignition-Di...QAAOSwwCJdCrNY
Reply
Old Jun 16, 2025 | 10:36 AM
  #25  
Stumpdeisel's Avatar
Stumpdeisel
Thread Starter
Racer
20 Year Member
Conversation Starter
All Eyes On Me
Liked
 
Joined: Dec 2004
Posts: 416
Likes: 11
From: Merrick NY
Default

Originally Posted by OldCarBum
American Auto Wire just came out with a new C3 complete wiring harness for restomods.
New blade type fuses and upgraded for high amp alternators and other nice features.
It will plug into all your oem equipment or it can be ordered to use with other upgraded gauges etc.
I just received mine and it is a very nice harness.
For the electric headlight conversion, p.m. Richard454 for his “complete” conversion kit.
I recently purchased his kit and it is top quality and dealing with Richard was great.
It is the best one offered on the market.

Reviving this thread, this time it's for real! I have a shop lined up to take on the car, and the parts are arriving with the harness the first to arrive...
Reply
Old Jun 23, 2025 | 11:52 AM
  #26  
fazang's Avatar
fazang
Racer
20 Year Member
Liked
Loved
Community Favorite
 
Joined: May 2005
Posts: 399
Likes: 4
From: Suffield CT
Default

Hi, did not want to keep hi-jacking the other thread. I forgot about the fuel pressure so yeah hunting down a fuel cell with in-tank pump is a must. Since you went 5-speed did you bring along the 97 PCM ? My 96 Imp SS was 4L60E and the PCM did talk to the tranny not sure it is the same in a stick shift ?

I'll try go back and read to catch up on the build progress.
Later,
-ALF
Reply
Old Jun 23, 2025 | 01:08 PM
  #27  
Stumpdeisel's Avatar
Stumpdeisel
Thread Starter
Racer
20 Year Member
Conversation Starter
All Eyes On Me
Liked
 
Joined: Dec 2004
Posts: 416
Likes: 11
From: Merrick NY
Default

Originally Posted by fazang
Hi, did not want to keep hi-jacking the other thread. I forgot about the fuel pressure so yeah hunting down a fuel cell with in-tank pump is a must. Since you went 5-speed did you bring along the 97 PCM ? My 96 Imp SS was 4L60E and the PCM did talk to the tranny not sure it is the same in a stick shift ?

I'll try go back and read to catch up on the build progress.
Later,
-ALF
I am using the a factory PCM, at the time there was no ODB2 harness kit available so I had to convert the car to ODB1. I had originally used MadZ28 for my first tune after installing the hotcam valvetrain with good success so I swapped that PCM with a tuned ODB1 PCM. There are quirks that I vaguely remember such as reverse lockout and alarm/security override with may have been part of the initial startup problems. Either way it's now in the hands of a professional, fingers crossed...
Reply
Old Jun 23, 2025 | 01:12 PM
  #28  
Stumpdeisel's Avatar
Stumpdeisel
Thread Starter
Racer
20 Year Member
Conversation Starter
All Eyes On Me
Liked
 
Joined: Dec 2004
Posts: 416
Likes: 11
From: Merrick NY
Default

Update: The car has officially left for the shop! Tomorrow they'll go through it and I get an initial estimate/ work plan and hopefully they start turning wrenches on Wed..
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

10 Ugly Corvettes That We Still Kinda Love

 Joe Kucinski
story-1

Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

 Brett Foote
story-2

10 Things Every Corvette Owner Needs (2026 Edition)

 Michael S. Palmer
story-3

8 Most "Only Corvette Owners Understand" Quirks and Problems

 Pouria Savadkouei
story-4

10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

 Joe Kucinski
story-5

How Much Horsepower Every Corvette Engine "LOST" in 1972

 Joe Kucinski
story-6

Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

 Michael S. Palmer
story-7

Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

 Joe Kucinski
story-8

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-9

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
Old Jun 23, 2025 | 01:20 PM
  #29  
fazang's Avatar
fazang
Racer
20 Year Member
Liked
Loved
Community Favorite
 
Joined: May 2005
Posts: 399
Likes: 4
From: Suffield CT
Default

Originally Posted by Stumpdeisel
I am using the a factory PCM, at the time there was no ODB2 harness kit available so I had to convert the car to ODB1. I had originally used MadZ28 for my first tune after installing the hotcam valvetrain with good success so I swapped that PCM with a tuned ODB1 PCM. There are quirks that I vaguely remember such as reverse lockout and alarm/security override with may have been part of the initial startup problems. Either way it's now in the hands of a professional, fingers crossed...
Hi, AFA this
alarm/security override

we used to call it VATS, and yes car won't run, but it will still crank, and start for like 2 seconds, sounds like you couldn't even get that far....?
Hard to find shops willing to work on 90's stuff especially with 3-4 yr only run of the LT1, so hope you already know this place or keeping a close eye on things.
The rabbit hole can get deep quick.
were you on here already back in the day?
https://www.ls1lt1.com/
tons of info here too on LT1 swaps/ obd1 to obd2/ etc....
https://www.impalassforum.com/

i mail order tuned with this guy if you need one more option https://lt1swap.com/programming.htm
Later,
-ALF
Reply
Old Jun 23, 2025 | 01:29 PM
  #30  
Stumpdeisel's Avatar
Stumpdeisel
Thread Starter
Racer
20 Year Member
Conversation Starter
All Eyes On Me
Liked
 
Joined: Dec 2004
Posts: 416
Likes: 11
From: Merrick NY
Default

Originally Posted by fazang
Hi, AFA this
alarm/security override

we used to call it VATS, and yes car won't run, but it will still crank, and start for like 2 seconds, sounds like you couldn't even get that far....?

-ALF
You nailed it, check this video, it's so old phones didnt have HD cameras but you can hear it ...almost.. start.

Reply
Old Jun 23, 2025 | 01:34 PM
  #31  
fazang's Avatar
fazang
Racer
20 Year Member
Liked
Loved
Community Favorite
 
Joined: May 2005
Posts: 399
Likes: 4
From: Suffield CT
Default

You can have it tuned out of the PCM, and....


Reply
Old Jun 28, 2025 | 02:49 PM
  #32  
ctmccloskey's Avatar
ctmccloskey
Safety Car
Supporting Lifetime
25 Year Member
Active Streak: 30 Days
Active Streak: 60 Days
Liked
 
Joined: May 2001
Posts: 4,759
Likes: 1,647
From: Fairfax Virginia
Default

Hello again Stumpdiesel!

I apologize for taking so long to answer your questions. The reason I went to an internal fuel pump was simple. NOISE The in-tank fuel pump and regulator keep me from needing a return lines for my EFI system.

The best tool I know of for working on the electrical side of our Corvettes is a tool called a Power Probe. This tool allows you to put either 12 volts or ground at the tip simply by rolling a rocker switch. I tested my fuel pump at the pump first, It ran. I then powered the Fuel Pump relay and it worked. Finally I found a bad voltage drop that was the cause. I fixed it and the problem was gone forever.

The LT1 engine and it OPTIonal ignition system would not have been my first choice for a transplant engine. I don't care for the design work where they put the distributor under the water pump.

By the way, Ether spray will ignite in an engine with NO Ignition and/or spark. It should not be used for testing the spark. Why do you think that we use it in diesel engines?
Reply
Old Sep 18, 2025 | 03:43 PM
  #33  
Stumpdeisel's Avatar
Stumpdeisel
Thread Starter
Racer
20 Year Member
Conversation Starter
All Eyes On Me
Liked
 
Joined: Dec 2004
Posts: 416
Likes: 11
From: Merrick NY
Default

I was able to find my original tune order, and it looks like all the non essentials were disabled:

Options

-------


Powertune Selected.

Disable Skip Shift.
Disable EGR.
Disable AIR.
Disable CCP codes.
Disable VATS.

Project Update - pics in my album:

All underside work has been completed:
Brakes: New calipers, lines & pads, rotors shaved
Fuel: New tank w/ internal pump and lines installed
Suspension: All bushings replaced
Rear: half shafts redone & rear serviced
Exhaust: Fully installed

Remaining work:
* Install new harness
*Troubleshoot no spark/injector firing issues for motor to run
*Suspension setup, alignment and tune
*Install the interior and finally drive it!!!
Reply




All times are GMT -4. The time now is 06:05 PM.

story-0
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-1
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE
story-2
10 Things Every Corvette Owner Needs (2026 Edition)

Slideshow: 10 great gifts Corvette enthusiasts actually want for Father's Day!

By Michael S. Palmer | 2026-06-03 15:43:40


VIEW MORE
story-3
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE
story-4
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

Slideshow: 10 reasons why the C6 Z06 is still a performance benchmark after 20 years.

By Joe Kucinski | 2026-05-27 17:20:09


VIEW MORE
story-5
How Much Horsepower Every Corvette Engine "LOST" in 1972

Slideshow: How much horsepower every Corvette engine lost in 1972.

By Joe Kucinski | 2026-05-27 16:54:53


VIEW MORE
story-6
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-7
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-8
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-9
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE