checking the timing on a 91 k1500 5.7

[JACKFAVOR]

What is the proper way way to check the timing on 1991 K1500 5.7lt 4x4? I know that on vehicles with vacume advance you need to disconect and plug it but there is no vac. advance on the 91 do you have disconect something else? what should the timing be @in park ideling?

 

Thanks

Jack

[90GMCZ71]

What is the proper way way to check the timing on 1991 K1500 5.7lt 4x4? I know that on vehicles with vacume advance you need to disconect and plug it but there is no vac. advance on the 91 do you have disconect something else? what should the timing be @in park ideling?

 

Thanks

Jack

 

<{POST_SNAPBACK}>

 

 

 

You need to disconnect the EST connector to set the timing. It a black wire with a tan strip under the black cover on the passenger side firewall.

 

Specs are 0 degrees with EST disconnected.

 

I have noticed on my 90 that the timing will be at 20 when I reconnect the EST (if yours is not at 20, then you should disconnect the EST to set it).

 

//90GMCZ71