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Timing for 1991 L98

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Old Aug 6, 2009 | 07:41 PM
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Default Timing for 1991 L98
I just traded for a 1991 L98 recently and had to replace the manifold gaskets (coolant leak due to running hot). After all was put back together (new secondary fan, 195 thermostat, new coolant of course, cleaned the lower shroud cavity and removed all wasp nests from radiator) I went to set the timing per the manual (6 degree advanced). Per the instructions, I unplugged what I believed to be the ECM wires (4-wire connector) from the distributor. The engine turned, but wouldn't fire. I reconnected the plug - turned the keyswitch - engine ran. Unplugged connector - turned the keyswitch - engine didn't run. Reconnected the plug, again - turned the keyswitch - engine ran. So I set the timing to 6-8 degrees with the connector intact. Can someone tell what I've got here? I'm not sure where to go with this, but I still have an issue with the temp being borderline too high and before I re-address the temp I'd like to make sure the timing isn't a factor. Do I have another issue here or did I locate the wrong connector? It comes directly off of the rear of the distributor to a large harness against the firewall. Also, I keep reading about an air-bleed off for the cooling system - how do I address that? (sorry for the editorial - haven't had a 'vette since my 1975)
jimm
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Old Aug 6, 2009 | 07:48 PM
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Wrong connector, you want the single tan wire connector. Should be beside brake booster, towards the DS valve cover.
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Old Aug 6, 2009 | 07:49 PM
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Originally Posted by jimm07
Per the instructions, I unplugged what I believed to be the ECM wires (4-wire connector) from the distributor.
You disconnected the dist completely.
EST connector is single wire unit coming out of firewall harness (tan wire? , got go check)
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Old Aug 6, 2009 | 07:50 PM
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Originally Posted by AGENT 86
Wrong connector, you want the single tan wire connector. Should be beside brake booster, towards the DS valve cover.

AS Agent 86 would say " missed by that much"!
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Old Aug 6, 2009 | 07:53 PM
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Originally Posted by rodj

AS Agent 86 would say " missed by that much"!
So true
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Old Aug 6, 2009 | 07:55 PM
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Originally Posted by AGENT 86
Wrong connector, you want the single tan wire connector. Should be beside brake booster, towards the DS valve cover.
Here is a write-up on how to do it complete with photos of the brown EST connector you are looking for. Good luck
Attached Files
File Type: doc
Corvette L98 Ignition Timing.doc (138.0 KB, 1105 views)
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Old Aug 6, 2009 | 08:30 PM
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That's what she said !!!!

thanks guys for the quick response - i'm out the door with my timing light
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Old Aug 6, 2009 | 09:35 PM
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just a heads-up
all done - took longer to log out and back into the site to thank you all, once you guided me in the right direction
thanks
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Old Aug 7, 2009 | 03:20 PM
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Originally Posted by rodj
You disconnected the dist completely.
EST connector is single wire unit coming out of firewall harness (tan wire? , got go check)
that's what the FSM says to do (wrong obviously)...
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Old Aug 7, 2009 | 09:01 PM
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So, you want it set to the 6 degree on the "Before"?
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Old Aug 7, 2009 | 09:29 PM
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Originally Posted by joshwilson3
So, you want it set to the 6 degree on the "Before"?
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