C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Dizzy issues --

Thread Tools
 
Search this Thread
 
Old 08-13-2017, 01:25 PM
  #1  
3D-Aircrew
Melting Slicks

Support Corvetteforum!
Thread Starter
 
3D-Aircrew's Avatar
 
Member Since: Nov 2007
Location: Gainesville FL
Posts: 2,830
Received 145 Likes on 112 Posts

Default Dizzy issues --

So my car was running rough, no codes and I figured that it was probably time to change spark plugs and dizzy cap/rotor since that's what happened last time it was running rough. Sure enough the cap and rotor was badly corroded as well as the center contact of the HEI coil. I bought an MSD 8416 cap and rotor which was supposed to be an exact fit for my 1986.




Well I got it and it isn't held down with screws or bolts but spring loaded clamps. It forces you to advance or retard the timing ~ 10-15 degrees because the clips do not line up with the flanges on the dizzy.

I put it on anyway and tried to advance the timing. ;(


PS- Returned the POS MSD cludge and got a refund. It so happens that I had a Duralast cap on there before and I had kept the box so I returned that for new one free.

I got it all back together and the dizzy in the approximate position it was before and with the EST disconnected the thing won't start. Now I'm at a loss and kicking myself for adjusting the timing when I should have returned the POS MSD cap when I saw the latch system and just left it alone.

1st problem: Can't see the timing mark on the motor with my timing light. So I made an educated guess where the dizzy should be and put it there. Engine runs but coughs and sputters when I gave it gas.

2nd try moving the dizzy and with the EST disconnected engine runs smoothe and I can rev it without misses. So I reconnected the EST and disconnected the battery. Started again and it runs horribly. Pops and coughs when revved.


Is it possible that my EST was at fault all along?

Thoughts

Last edited by 3D-Aircrew; 08-13-2017 at 04:17 PM. Reason: PS-added
Old 08-13-2017, 04:35 PM
  #2  
xrav22
Drifting
 
xrav22's Avatar
 
Member Since: Mar 2013
Location: Venice Cali.
Posts: 1,952
Received 235 Likes on 218 Posts

Default

I had the problem with coughing ,popping after adjusting my timing before. Nothing was wrong, I just tried to adjust it. A close reference is to have #1 plug wire at dizzy at 5 oclock. That should put your timing mark in range. Now mine I forgot to disconnect the advance and it ran terrible. I had to try a few times starting, driving to get it to be right.
Try setting things and disconnect battery to reset everything.
The following users liked this post:
3D-Aircrew (08-13-2017)
Old 08-13-2017, 05:56 PM
  #3  
3D-Aircrew
Melting Slicks

Support Corvetteforum!
Thread Starter
 
3D-Aircrew's Avatar
 
Member Since: Nov 2007
Location: Gainesville FL
Posts: 2,830
Received 145 Likes on 112 Posts

Default

Originally Posted by xrav22
I had the problem with coughing ,popping after adjusting my timing before. Nothing was wrong, I just tried to adjust it. A close reference is to have #1 plug wire at dizzy at 5 oclock. That should put your timing mark in range. Now mine I forgot to disconnect the advance and it ran terrible. I had to try a few times starting, driving to get it to be right.
Try setting things and disconnect battery to reset everything.
I returned the POS MSD cludge and got a refund. Also the old dizzy cap had a lifetime warranty so I just took it back and got another one this afternoon.
After double checking firing order I found they were bass-akwards IAW the bottom of the wire cover and your suggestion.

Once sorted, it started but ran rough. Was able to see the timing light and marks and it was at 0 degrees ... ADJUSTED to 6 degrees BTDC ... and it ran as well as it did when I started which is bad. So it wasn't my dizzy cover after all. Got fire on all 8 plugs so I'm hoping for fouled plug somewhere ... next.
Old 08-13-2017, 06:38 PM
  #4  
xrav22
Drifting
 
xrav22's Avatar
 
Member Since: Mar 2013
Location: Venice Cali.
Posts: 1,952
Received 235 Likes on 218 Posts

Default

Check this video out I was sloppy with my grease and having misfires because of it.
I had to clean everything up and found a few boots weren't clicked on fully.
.
Old 08-13-2017, 08:52 PM
  #5  
3D-Aircrew
Melting Slicks

Support Corvetteforum!
Thread Starter
 
3D-Aircrew's Avatar
 
Member Since: Nov 2007
Location: Gainesville FL
Posts: 2,830
Received 145 Likes on 112 Posts

Default

So to make a long story short ... the original problem was caused by fouled plugs likely caused by weak spark from the corroded dizzy cap. All better now .... thanks!




How they came out LF on the bottom RF on top

Last edited by 3D-Aircrew; 08-14-2017 at 05:05 PM.

Get notified of new replies

To Dizzy issues --




Quick Reply: Dizzy issues --



All times are GMT -4. The time now is 12:39 PM.