ashamsuddin

Found my vacuum advance was bad, so I replaced the distributor (cheaper than just the advance). Have the idle set, disconnect both vacuum lines from the distributor, set timing to zero, reconnect lines, and it only advances to about 5 - and this is with the truck at operating temperature. Shouldn't it advance to 12?

abecedarian

Not necessarily.

If you rev the engine up, what does it advance to?

ashamsuddin

I noticed that when I start it cold, it does advance to 12 degrees. Also, I have the idle set to about 740. When I disconnect the hoses to the distributor (this is at normal operating temp now), the idle drops to about 650. Is this also normal? Or do I set the idle to 700 AFTER I disconnect the vacuum hoses?

slow-mo

It will advance up to 12 degrees. There's a range of advancement, not a fixed amount.


Yes, that is normal.


After setting the timming to 0 degrees with the hoses off, reconnect the vacuum hoses and if need be, set your idle speed to Toyota's specification for you transmission type, i.e. automatic or manual.


As to the distributor/vacuum advance only advancing the timing to 5 degrees, check with a hand vacuum pump that the new vacuum advance on the new distributor is holding vacuum. Check both vacuum diaphragms.

ashamsuddin

Will do, thanks.

4x4jeffyota

Sorry for thread jacking but I really have to ask this. When I take the vacuum lines of the advance is there suposed to be suction? Bc I put my fingers on it and I feel nothing. Again, sorry for thread jacking man.

ashamsuddin

No problem. On mine, at idle you should have vacuum at the port closest to the engine. I believe the other port should get vacuum at higher RPMs.

4x4jeffyota

Alright can I clean it out with anything or is it pretty much toast?

ashamsuddin

Suction should be coming from the vacuum lines, not the advancer unit. Mine was toast and it was cheaper to replace the whole distributor. If you have no suction coming in on either vacuum line, then you've got other problems.