Vacuum advance.....

[87'GTstang]

On an 87' 5.0, how do you prepare the engine for base ignition timing? I know the rest and all anyway but How do you disable the advance on the distributor so you could check for the 10 degrees BTDC? I get 23 with advance at idle which I know is in the range for idle with advance, but how do you disable the advance?

 

[ALMOSTFINISHED]

You will see the spiut connector near the ase of the distributor, it is connected to the harness that goes to the tfi module. remove the connector and you will put the computer into base timing. Once you finish adjusting the timing then reconnect the spout connector.
hope this helps
Nick

 

[87'GTstang]

Thanks a lot. Anytime I hear the word vacuum, I want to look for a hose of some sort. I'll give it a try tomorrow, thanks a lot!

 

[Michael Yount]

The 'spout' simply connects the computer to the tfi module allowing the computer to add/subtract timing. There is no 'vacuum' advance on the efi Stang engines. Think of the spout like a toggle switch - with it in, the toggle is 'on' allowing computer to control the timing; with it out, the toggle is 'off' disconnecting the computer from timing control. Some racers simply leave the spout out and set the timing where they want it at for total timing - up around 34 degrees btdc. Not recommended for the street.

 

[04sleeper]

Here are some photos that might assist you.

 

[87'GTstang]

Thanks a lot! The photos were also a big help.