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

Distributor help

Thread Tools
 
Search this Thread
 
Old May 28, 2019 | 01:42 PM
  #1  
RocketNerd's Avatar
RocketNerd
Thread Starter
Advanced
 
Joined: Dec 2017
Posts: 78
Likes: 18
From: Hawai'i, Island of Kaua'i
Default Distributor help

I think my dizzy has some issues. I've been trying to get rid of the bog I feel when I hit the gas to accelerate hard. Going smoothly, i can baby it into the higher RPM's, but any more than that and it bogs significantly, hesitating until a second or so later and it accelerates. I had the carb cleaned, rebuilt, and tuned by Lars and its been worlds better. So i am thinking its my timing. taking a light to the engine, plugged the vac. advance, I noticed my initial is set somewhere around 22, when i give it some RPM's the advance only moves about 8 degrees in total, and is all in around 2800. I then moved the dizzy to be all-in to be at the 36 degrees and my initial goes way up, outside of the timing tab. when its at 36 all in, i decided to take it for a quick spin to see how it did, felt smooth and no more hesitation on the pedal, however when i got home, i realized i hadn't connected the vac. advance, so I let it cool and did so. Driving this morning after a nice warmup, it had the same issues with the hesitation when i give her more than 1/4 throttle, now that the vac. adv has been put back on.

I'm still very new to this game, and I am looking for home help from this well of knowledge. Do i need to adjust my springs, do i need a new vacuum advance, is there something i'm missing that will help me dial it in and get it within the specs? Is it time to buy a new drop-in MSD dizzy altogether?

Its a 1976, AT, and the block is not the original, is a Goodwrench 350 from Mexico the previous owner replaced years ago. I have no intent to keep this original. Thanks in advance (no pun intended).
Reply
Old May 29, 2019 | 08:25 AM
  #2  
Rescue Rogers's Avatar
Rescue Rogers
Is my vette stock?? HAHA
Supporting Lifetime Gold
Veteran: Navy
10 Year Member
Community Builder
Loved
 
Joined: Oct 2015
Posts: 20,036
Likes: 9,157
From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
Default

Some people do run without the vacuum advance but you loose some low end mileage and around town drivability. Each motor will vary a bit on that. Contact Lars again and get his timing and distributor papers. He updates them so the ones you'll find in a search are sometimes out of date. You are a bit high on your initial and you need to reset your idle once the vacuum advance it attached but you can get too much vacuum advance too. Look and see what the total is with vacuum advance, Lars recommends staying below 50* with todays gas.

For comparison my initial is 14, 36 total and 48 with vacuum advance. Stock didtributor vac advance cans have a plastic round shim on the end of the arm to limit how much advance you get. When it falls apart the bare arm can give you way too much advance. Rebuild spring and weight kits can come with a brass shim that is pressed onto the arm to restore and limit the travel. You may wan tot take the cap and rotor off and see whats going on in there. The PO may have monkeyed with it to give him what he wanted for travel and advance. You can ask Lars about rebuilding it too. He may still do distributors.

As for the bog, once you get the distributor sorted, i would recheck the carb. If your secondary air flap is opening to fast you will get the bog. ITs adjusted on the passenger side near the choke limit

Last edited by Rescue Rogers; May 29, 2019 at 08:29 AM.
Reply
Old May 29, 2019 | 09:27 AM
  #3  
RocketNerd's Avatar
RocketNerd
Thread Starter
Advanced
 
Joined: Dec 2017
Posts: 78
Likes: 18
From: Hawai'i, Island of Kaua'i
Default

@Rescue Rogers Thank you for the help. I contacted Lars a few months ago when to get his papers when I started my front end rebuild, and he also included the Timing papers. They were a great help, but you are right, I think i need to get into the cap/rotor and see whats going on in there.
Reply
Old May 29, 2019 | 04:13 PM
  #4  
pltmgr's Avatar
pltmgr
Melting Slicks
Supporting Lifetime Gold
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Oct 2003
Posts: 2,105
Likes: 789
From: Chapel Hill NC
2025 c3 ('68-'73) of the Year Finalist - Unmodified
2025 C4 of the Year Finalist - Unmodified
2025 C8 Stingray of the Year Finalist - Unmodified
Default

No expert here but if it advance only 8 degrees Id check the weights and the the slot that limits total mechanical advance.
Reply

Get notified of new replies

To Distributor help





All times are GMT -4. The time now is 01:05 PM.

story-0
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE
story-1
2027 Corvette vs The World: Every Model vs Closest Competitor

Slideshow: 2027 Corvette lineup vs the world.

By Joe Kucinski | 2026-04-20 17:58:41


VIEW MORE
story-2
10 Most Common Corvette Problems of the Last 20 Years!

Slideshow: 10 major Corvette problems from the last 20 years.

By Joe Kucinski | 2026-04-14 16:37:05


VIEW MORE
story-3
5 MOST and 5 LEAST Popular Corvette Model Years in History!

Slideshow: 5 most and least popular Corvette model years.

By Joe Kucinski | 2026-04-08 13:25:01


VIEW MORE
story-4
2027 Corvette Buyer's Guide: Everything You Need to Know!

Slideshow: 2027 Corvette buyer's guide

By Joe Kucinski | 2026-04-17 16:41:08


VIEW MORE
story-5
10 Things C8 Corvette Owners Hate (But Won't Tell You)

Slideshow: 10 things C8 Corvette owners hate, but won't tell you.

By Joe Kucinski | 2026-04-01 18:36:07


VIEW MORE
story-6
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!

Slideshow: Should you add one of these incredible Corvettes to your garage?

By Brett Foote | 2026-04-01 18:14:05


VIEW MORE
story-7
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)

Slideshow: Every Corvette Grand Sport explained

By Joe Kucinski | 2026-03-26 07:13:44


VIEW MORE
story-8
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!

Slideshow: Breaking down the 2027 Grand Sport, Grand Sport X, Stingray, and LS6 V8.

By Michael S. Palmer | 2026-03-26 13:48:45


VIEW MORE
story-9
5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!

Slideshow: 5 reasons bad drivers crash sports cars & 5 ways to avoid a costly shame!

By Joe Kucinski | 2026-03-25 16:32:55


VIEW MORE