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

EFI Controlled Distributor

Thread Tools
 
Search this Thread
 
Old Mar 18, 2017 | 05:04 PM
  #21  
zwede's Avatar
zwede
Race Director
25 Year Member
Loved
Community Favorite
Top Answer: 1
 
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
Default

http://documents.holley.com/techlibr...10555rev17.pdf

Page 20 has the wiring diagram that is closest to your setup. In your case the crank signals comes from the distributor, so ignore the crank trigger. The CDI and coil part applies to you.
Reply
Old Mar 18, 2017 | 05:09 PM
  #22  
zwede's Avatar
zwede
Race Director
25 Year Member
Loved
Community Favorite
Top Answer: 1
 
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
Default

I don't really see the point in you using the dual sync though. It provides a cam sync which allows port injection systems to run the injectors sequentially. But you have throttle body injection so you can't use sequential mode anyway. I'd recommend a regular 8-pin small cap HEI distributor instead. It plugs right in to the holley system, and you don't need a CDI box as the HEI module drives the coil.
Reply
Old Mar 18, 2017 | 06:32 PM
  #23  
greghennings's Avatar
greghennings
Thread Starter
Instructor
10 Year Member
Conversation Starter
All Eyes On Me
 
Joined: Nov 2012
Posts: 209
Likes: 7
Default

Originally Posted by zwede
I don't really see the point in you using the dual sync though. It provides a cam sync which allows port injection systems to run the injectors sequentially. But you have throttle body injection so you can't use sequential mode anyway. I'd recommend a regular 8-pin small cap HEI distributor instead. It plugs right in to the holley system, and you don't need a CDI box as the HEI module drives the coil.
So I understand the cdi box gets triggered by the white points out wire, but I'm supposed to hook it to the loose white wire in my ECU harness that's labeled "not used" ? and my terminator manual says to never, never connect any of the ECU wires to the cdi box. Makes me a little nervous.

I really only wanted it because of the timing advance and that it was supposed to plug and play with my ECU which it is but nothing else about it is. I'm probably stuck with it now so I gotta make it work.

Last edited by greghennings; Mar 18, 2017 at 06:33 PM.
Reply
Old Mar 18, 2017 | 07:02 PM
  #24  
greghennings's Avatar
greghennings
Thread Starter
Instructor
10 Year Member
Conversation Starter
All Eyes On Me
 
Joined: Nov 2012
Posts: 209
Likes: 7
Default

Two other things, I should remember that the ECU for my terminator setup is a hp ECU so if I follow the manual you posted zwede I should be fine right?

Also I remember now the retail price for Holley's distributor is $429, and I wasnt going to pay that but summit had a sale going the week of Christmas and I picked it up for $386. So that's another why I bought it.
Reply
Old Mar 18, 2017 | 08:02 PM
  #25  
zwede's Avatar
zwede
Race Director
25 Year Member
Loved
Community Favorite
Top Answer: 1
 
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
Default

Terminator manual p.14:

http://www.jegs.com/InstallationInst...10-550-405.pdf

Points Output – Color = White – Used for ignition configurations that must be configured with a laptop computer. See pages 13-21 in
the Holley EFI Wiring Manual, located at http://documents.holley.com/techlibr...10555rev17.pdf or go to www.holley.com, click on
SUPPORT, then TECH SERVICE, scroll down and click Resource Documents & Library. Go to the Fuel Injection tab and scroll down to
the Holley EFI Wiring Manual.
and my terminator manual says to never, never connect any of the ECU wires to the cdi box.
I think you misread the warning (bolding mine):

CAUTION! NEVER, NEVER connect any of the EFI wires to the coil on any CD type ignition system. The ECU will be permanently
damaged!
If you currently have the yellow wire connected to the coil, you must disconnect it when you add the CDI. You will use the crank trigger input instead of the yellow wire (yellow wire will be unused).

Last edited by zwede; Mar 18, 2017 at 08:05 PM.
Reply
Old Mar 18, 2017 | 08:30 PM
  #26  
greghennings's Avatar
greghennings
Thread Starter
Instructor
10 Year Member
Conversation Starter
All Eyes On Me
 
Joined: Nov 2012
Posts: 209
Likes: 7
Default

Ah yeah, now that's all making sense . I definitely read that line wrong, this sounds good now. I'll get that CD box ordered up, should have it by wednesday, zwede where did you put your? i'm starting to run out of real-estate under my hood. I'm thinking behind/next to the power brake booster there's a nice cubby but i've already got a vacuum reservoir jammed in there, i could re-route that with less complications...
Reply
Old Mar 18, 2017 | 10:43 PM
  #27  
zwede's Avatar
zwede
Race Director
25 Year Member
Loved
Community Favorite
Top Answer: 1
 
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
Default

I put it on the passenger side wheel well, underneath the coolant tank. Pretty good access to that area with the gill removed.

A tip is to twist the wires going from the CDI to the coil. Drastically cuts down on interference (it cancels out the EMI). And you need a good power feed to the CDI, I took mine off the starter. The ground can go to the frame or engine, doesn't matter.
Reply
Old Mar 24, 2017 | 09:07 PM
  #28  
greghennings's Avatar
greghennings
Thread Starter
Instructor
10 Year Member
Conversation Starter
All Eyes On Me
 
Joined: Nov 2012
Posts: 209
Likes: 7
Default

Well i got it going finally. I got my Summit Racing CDi box, my ECU is already occupying my passenger wheel well, so i ended up removing my washer fluid reservoir and mounting the cd box to the fiberglass/firewall underneath the power brake booster. Worked perfectly! Its perfectly flat and you can get your arm down behind it and use the rubber stands and nuts. Wiring was no problem, only difficulty was getting to the starter positive terminal, i had to add on to the wire but no problem. Fired right up.

I've got a little tweaking to do, right now it run ok. But it'll stall if i rev it up and let off the gas right away. Or like when i start it it'll high idle and then low idle and die. I can keeping running with just a little throttle.

I think i need to adjust the inductive delay. The manual say to use "enable static timing" in the software, which i did. It comes up "set timing value" Well the manual doesn't say what to set it at or what to do with it. How do i use this? Or should i just use my timing light and check it versus what my monitor says it is and adjust the inductive delay that way?
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

2027 Chevrolet Silverado 1500 First Look: Everything You NEED to Know!

 Michael S. Palmer
story-1

5 Best & 5 Worst Corvette Daily Drivers

 Joe Kucinski
story-2

The Headlights of Every Corvette Generation Explained

 Joe Kucinski
story-3

5 Best & 5 Most Overrated Corvette Track Packages of All Time!

 Joe Kucinski
story-4

Every 2027 Corvette Engine Explained

 Joe Kucinski
story-5

Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette

 Verdad Gallardo
story-6

10 Ugly Corvettes That We Still Kinda Love

 Joe Kucinski
story-7

Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

 Brett Foote
story-8

10 Things Every Corvette Owner Needs (2026 Edition)

 Michael S. Palmer
story-9

8 Most "Only Corvette Owners Understand" Quirks and Problems

 Pouria Savadkouei
Old Mar 24, 2017 | 09:09 PM
  #29  
greghennings's Avatar
greghennings
Thread Starter
Instructor
10 Year Member
Conversation Starter
All Eyes On Me
 
Joined: Nov 2012
Posts: 209
Likes: 7
Default

Also, between my ecu and cdi box running directly off the battery, should a guy put a battery disconnect in some where and maybe shut it off if the cars not in use for a while?
Reply
Old Mar 24, 2017 | 10:31 PM
  #30  
zwede's Avatar
zwede
Race Director
25 Year Member
Loved
Community Favorite
Top Answer: 1
 
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
Default

ECU and CDI should not use any power with ignition off so no need for a battery disconnect.

To adjust the inductive delay you enable static timing as you found. The value you put in is what the advance will be while you do the test so you need to pick something that works for idle as well as reving it in neutral. 25 degrees is what I use. Then take a timing light to it and adjust so you have 25 degrees at idle. Next rev it to 3000 rpm and check again. If it's still 25 dgrs you're done. If it is not you adjust the inductive delay until it reads the same at idle and 3000 rpm. Finally disable static timing so everything is back to normal.
Reply
Old Mar 25, 2017 | 09:11 PM
  #31  
greghennings's Avatar
greghennings
Thread Starter
Instructor
10 Year Member
Conversation Starter
All Eyes On Me
 
Joined: Nov 2012
Posts: 209
Likes: 7
Default

ok that cleared up for me. i got that done. that's a really neat trick, i set it for 25 deg. it holds that 25 degs just solid all the way to 3000 rpm. I didn't have to adjust the inductive delay at all. So now, i've still got a bit of a stalling problem around idle. It will kill it i put in gear without a little throttle. Any ideas? I know some of you guys mentioned about the cdi boxes are better at high rpms then low rpms could that be the trouble? if so is there a way to compensate for that? the car before ran like a dream, i hate to go backwards in performance.
Reply
Old Mar 25, 2017 | 09:19 PM
  #32  
zwede's Avatar
zwede
Race Director
25 Year Member
Loved
Community Favorite
Top Answer: 1
 
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
Default

What's your timing map like? It needs to be stable around idle. You should have the same advance in neutral and in drive. What idle timing did you have before and what do you have now?

Last edited by zwede; Mar 25, 2017 at 09:20 PM.
Reply
Old Mar 25, 2017 | 09:19 PM
  #33  
greghennings's Avatar
greghennings
Thread Starter
Instructor
10 Year Member
Conversation Starter
All Eyes On Me
 
Joined: Nov 2012
Posts: 209
Likes: 7
Default

you know i got to thinking too. i had to update my firmware for the ecu and so i had to start over, i wonder if i just need to drive the thing so that it'll learn...
Reply
Old Mar 25, 2017 | 09:21 PM
  #34  
zwede's Avatar
zwede
Race Director
25 Year Member
Loved
Community Favorite
Top Answer: 1
 
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
Default

Yeah, if you started over with a default fuel map it needs to relearn.
Reply
Old Mar 25, 2017 | 09:25 PM
  #35  
greghennings's Avatar
greghennings
Thread Starter
Instructor
10 Year Member
Conversation Starter
All Eyes On Me
 
Joined: Nov 2012
Posts: 209
Likes: 7
Default

tomorrow morning i'll try and take it out and i'll watch what everything is doing.
Reply
Old Mar 29, 2017 | 08:31 PM
  #36  
greghennings's Avatar
greghennings
Thread Starter
Instructor
10 Year Member
Conversation Starter
All Eyes On Me
 
Joined: Nov 2012
Posts: 209
Likes: 7
Default

Oops, forgot to post from Sunday. Took the car out and filled it up with some fresh gas and put 20 miles on or so and it runs better. I think I gotta get a little more time on the road and it'll be fine. I'd say case closed.
Reply
Old Mar 29, 2017 | 09:44 PM
  #37  
zwede's Avatar
zwede
Race Director
25 Year Member
Loved
Community Favorite
Top Answer: 1
 
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
Default

Reply
Old Mar 30, 2017 | 12:28 AM
  #38  
bmans vette's Avatar
bmans vette
Race Director
Supporting Lifetime
15 Year Member
 
Joined: Nov 2006
Posts: 19,445
Likes: 353
From: Athens GA
St. Jude Donor '12-'13, '15- '16-'17-'18-'19, '21
Default

FYI.....the reason Holley recommends MSD is because they now own MSD.

Was just talking with a friend last weekend about MSD and he told me the horror story he had awhile back.
He changed everything over to Dakota Sensors.......

Changed the distributor to match the box. Has programmable rev limiter.

http://www.racingjunk.com/Ignition-S...on-System.html
Reply




All times are GMT -4. The time now is 11:57 PM.

story-0
2027 Chevrolet Silverado 1500 First Look: Everything You NEED to Know!

Slideshow: Is the 2027 Chevrolet Silverado 1500 the best Silverado yet?

By Michael S. Palmer | 2026-06-16 08:01:12


VIEW MORE
story-1
5 Best & 5 Worst Corvette Daily Drivers

Slideshow: 5 best and 5 worst Corvette daily drivers

By Joe Kucinski | 2026-06-15 10:32:13


VIEW MORE
story-2
The Headlights of Every Corvette Generation Explained

Slideshow: The headlights of every Corvette generation explained

By Joe Kucinski | 2026-06-15 10:17:14


VIEW MORE
story-3
5 Best & 5 Most Overrated Corvette Track Packages of All Time!

Slideshow: The 5 best and 5 most overrated Corvette track packages ever.

By Joe Kucinski | 2026-06-09 12:46:45


VIEW MORE
story-4
Every 2027 Corvette Engine Explained

Slideshow: Every 2027 Corvette engine explained

By Joe Kucinski | 2026-06-09 12:16:31


VIEW MORE
story-5
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette

Slideshow: A Jaguar designer's personal project imagines what a modern front-engined Corvette might look like if Chevrolet revisited the golden age of the Stingray.

By Verdad Gallardo | 2026-06-08 19:53:43


VIEW MORE
story-6
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-7
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-8
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-9
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