1985 xjs he vacuum advance module

Now that i’ve got my V12 idling smooth and running top, i decided to try that hookup again.

I had to turn idle screw out one full turn to get back to correct idle rpm.

First impressions, the idle sounds much deeper from exhaust pipes (i have no cats, no mid mufflers, only rear mufflers). And i swear it idles smoother and the throttle response at lower throttle is more linear with no lag if that makes sense.

Now, my timing @3000rpm is 22 BTDC instead of 18, because i run 92 octane instead of required 87. (USA) So maybe the stock 8inHg (or whatever that three inlet valve supplies to vacuum advance at idle) supplies too much advance at idle for me?

I’m going to keep it like this for a week and see if i like it. Less junk!

Second impressions…car idles a bit worse when cold, and throttle response is bad when cold. Once warmed up, idle is fine, maybe same as before, maybe better, hard to tell. But throttle response when warm from a stop to flooring it not as good.

I’m going back to OEM setup!

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