92cobra

ive got a thought. I was having a problem with my TFI module, and someone told me that if i wanted to, i could disconnect the SPOUT connector, and run my car at around 30* of timing. Try to do this. Disconnect your spout connector, and leave your base timing at 30*, this means that at higher rpms, your timing will still be at 30*. I dunno, just a suggestion, see if it works.

hot85fifty

Do carbed cars have spout connectors? Im thinking your saying disconnect my vacuum advance and leave the timing set at 30* no matter where in the rpm range it is right? Idle will Be 30* and when you rev it it wont change because its has no vacuum to advance it. ill try that later and seehow it runs.

Any other thoughts?

AdderMk2

a carb distributor actually advances timing with a LACK of vaccum...

If your timing is in fact at 68°, you have problems... you need to pull your distributor and re-zero the system.

When you disconnect your vac reffereance, you shouldnt be running any more than 30-34° total timing

hot85fifty

I have got it to TDC on #1 and re stabed the distributor. The car wont run unless it has 30* of timing with or without the vacuum line hooked up. when its hooked or un hooked it dosent make a difference.

AdderMk2

A stock mustang with an A9L computer runs approximately 28° advanced at idle, the highest timing in the computer is about 41-43°... i realistically cant see why you would run 68° timing

frdmstng1986GT

did the computer control timing in 85? judgeing from his name i am guessing he has an 85.

ZachW04Stang

Hey copied this for you from a online article. When theres no load its normal to see 60* just read this:

Copied from:http://www.fordmuscle.com/archives/2...ng/index.shtml

Vacuum Advance: Most Ford distributors include a vacuum advance mechanism. This consists of a diaphragm vacuum canister, an arm from the canister to the breaker plate, and a hose connected to an engine vacuum source. The purpose of this mechanism is to provide spark advance when the engine is not spinning fast enough to create the centrifugal advance talked about earlier. In other words this is an engine-load dependent advance. This would be a typical situation when climbing a steep hill, or driving at low rpms, light throttle, conditions. In these conditions there is high engine vacuum, so the vacuum signal applied to the diaphragm in the canister, via the hose, will cause a 'pull' effect on the arm, which moves the breaker plate and results in a timing advance. During full throttle conditions there is very little engine vacuum, and thus the vacuum advance does not contribute to total advance.

Vacuum advance is tricky to tune because there is no direct measurement like total. In fact, the reason you must measure initial and total timing with the vacuum hose disconnected is because when the engine is in neutral there no load, thus the vacuum is high, and if the hose were connected you'd see as high as 60 degrees advance and think something is really wrong! The only way to tune vacuum advance is on the road, by feel, and AFTER the initial and total are adjusted.

In short, vacuum advance was developed to optimize fuel economy and reduce emissions. It is not a bad thing to have on a car which sees a lot of street driving, and in such conditions the engine will perform better with it properly adjusted. However many factory and aftermarket performance distributors do not even come with a vacuum advance. The reason is simply because race cars do not spend much time at part throttle.

Joel5.0

Since you have a vacuum advance dizzy.....are you checking initial with the vacuum line disconnected?......does the vacuum line connected to the dizzy has vacuum at idle?.....keep in mind, that the vacuum line has to be connected to the "timed" port and not to a regular vacuum port.

hot85fifty

I have it connected to a timed port on the carb. with and without the vacume line on. it is at 30* at idle. when reved with it on it goes up to 68* of timing at 3500rpm. What is the best wat to set the timing? by feel like the article says? so drive it and whereever it has best power leave it? do i do that with the hose on or off?