Vacuum to both ports to attain proper Idle Advance

[FoxJDM]

Hey all

Long time lurker, first time poster....

I bought an 89 EXi 5 speed up here in canada land not long ago.

Old lady owned, great condition. Cheap.

Anyway, the Distributor bearing gave up within the first couple days, bought a new/reman from rock auto under the Spectra Premium brand. Seems like a decent unit.
I know the remans arent great, but good ones are very $$$.

Installed and timed with a light, I could not attain 15* with the vac line hooked up. Cold start line shuts off as it should.

Timing set to T mark without lines hooked up (and plugged off.)
Had to advance base timing 9* to attain 15* idle advance with line hooked up.

I also tried the diaphragm off the old dizzy and exact same thing.

So I took the line from the cruise control canister and actuator and hooked it to the cold start port on the advance diaphragm, and plugged the cold start hard line off.

Voila, 15* Vac advance with 1* advance BTDC.

Anyone else have this issue?
Is the issue that the car is not pulling enough Vac to start out with? What is the minimum spec for Idle Vac.

I know, I searched, but it seems there is a lot of un asked and un answered questions related to this.
Will see how the car behaves tommorow on the way to work.

Any info would be helpful.

Cheers!

[Dr_Snooz]

The timing inspection is extensive and covers 4 pages in the manual starting on p. 24-6. Basically, if you can set the base timing (with the lines unplugged) to 4 deg. BTDC, then the timing is set properly. You want to inspect the diaphragm to make sure it holds air and also make sure that you're getting a good vacuum supply from the manifold port. You also want to check the Ignition Control Solenoid Valve in the black box. Check out the manual for more info. It's also a good idea to make sure that your timing belt hasn't skipped a tooth. If you can't line up TDC by the marks on the cam gear and the flywheel, then you have a skipped tooth.

[FoxJDM]

Thanks for the reply
Just did the timing belt,(right after I did the dizzy)
double and triple checked all the marks before starting. Its all correct.

Both the new and old vacuum pot exhibit the same lack of vac advance.

No problem setting base timing. The T mark is dead steady on the pointer, maybe +1*
Distributor is at about the center of adjustment.

Pulled a 2nd vac source from an unused port on the manifold and routed to the cold start side. (Reconnected the cruise vac lines)

All seems ok and it makes its target advance of about 16*. Still runs a little 'funny'

I think its a crappy dizzy myself. Thinking if I keep the car, may go to OBD1.
The car is in really nice shape, Might be worth it.

[Dr_Snooz]

I would buy one of the new Richporters from eBay myself. I'm not having trouble at this point, but tempted to replace it anyway just for cheap insurance.