How do I set the timing?

JJJ

Petty Officer 2nd Class
Joined
May 12, 2005
Messages
158
How do I set the timing on a 96 4.3 Merc. with the IV ignition? I think there is some wire to ground? (where and which wire?)
thanks,
Jeff
 

Haut Medoc

Supreme Mariner
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Jun 29, 2004
Messages
10,645
Re: How do I set the timing?


If it is a TB IV, all you need to do is point at the timing tab.....
TB IV does not need to be put in base mode.....;)
 

Reel Poor

Vice Admiral
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Jan 29, 2005
Messages
5,522
Re: How do I set the timing?

No wire to ground on the TB IV ignition system. Just a simple adjustment for the TB IV system. The TB V system is the one that has a wire that has to be grounded.
 

JJJ

Petty Officer 2nd Class
Joined
May 12, 2005
Messages
158
Re: How do I set the timing?

Thanks, I'll double check but think it is the TB IV. It is the early 96 non good vortec head model.
 

Don S

Honorary Moderator Emeritus
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Aug 31, 2004
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62,321
Re: How do I set the timing?

Be sure what you have. The timing procedure is different between the Thunderbolt IV and TB V systems.
 

JJJ

Petty Officer 2nd Class
Joined
May 12, 2005
Messages
158
Re: How do I set the timing?

This might be a stupid question, but is there a quick and easy way to tell them apart?

When I look at
http://www.boatfix.com/merc/Techbk/techcov.pdf

mine really doesn't look like either system. I'm thinking now it might be the TB V system but with out the retard module.

I took on saltwater (cracked head) in June and just fired it up today. All appears to be ok with the lower end/block. I got the water out fairly quickly and circulated oil through the engine (by hand). Doesn't appear at this point anyways as if any damage was done to the rings/piston of that cylinder.

Figured I would take it to the river tomorrow and idle for awhile and set the timing/carb up.
 

Haut Medoc

Supreme Mariner
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Messages
10,645
Re: How do I set the timing?


Post up your serial # & remove all doubt.......;)
 

JJJ

Petty Officer 2nd Class
Joined
May 12, 2005
Messages
158
Re: How do I set the timing?

0f601245 is the engine serial.

It also says Thunderbolt IV ignition on the cover :)
Been awhile since I actually read what was on the cover, must be why the IV was stuck in the back of my mind :)

Thanks alot for the help.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: How do I set the timing?

The SN doesn't help in determining TBIV or TBV, wish it did.
IF you don't have both the knock control module, and the ignition module mounted on the distributor, then you have a TB IV ignition.
 
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