Before timing an LG4, you first need to disconnect the est 4-wire connector (which comes from the back of the distrib. and leads to the ECM) right?

I did disconnect that connector and set the timing but once in a while the idle would increase and i would lose the marking on the harmonic balancer, THEN the idle would decrease back and the marking would come back into range of the degree's indicator. This is what lead me to think that maybe I didnt disconnect the correct connector can the ECM was still controlling the timing. Can someone shed some light on me please. Thanks.

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Shouldn't bother putting this but hey what the heck:
1988 Maui Blue Firebird 305 TBI stock (w/ 190,000+ miles and still running strong )

 

here are a couple of links to tech articles i wrote on how to set your timing:
http://www.iroc-z.org/tech/distribut...ngdistrib.html
http://www.iroc-z.org/tech/distributor/settingtiming

My guess is either you did not disconenct the correct wire (it should have thrown the Code 42) or your car doesn't use the computer to set the timing but uses a Vacuum Advance.

If it uses the Vacuum Advance, remove the vacuum line from the vacuum advance on the distributor and plug it with a screw, then set your timing and replace it.

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Webmaster: www.IROC-Z.org

 

my other guess would be that your timing chain is getting sloppy and it is changing the cam timing..

that's a common problem on vehicles that are AT or NEAR, definitely OVER, 100,000 miles.

If you change your timing chain get a double roller, it will last essentially for forever (as long as you own your car)

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Webmaster: www.IROC-Z.org