vacuum problem analysis please!

[Soma576@xxxx]

Hello List,

i have a number of tests completed now in my plea for help from the smart 
guys out there.

to recap:
my car has been tuned for the last three years with two things wrong - 

1) the vacuum hose that goes to the distributer advance diaphram was plugged 
into the MIDDLE connector on the advance solenoid. this is wrong, it should 
have been plugged into the outer connector while the middle should go to the 
thermal control valve. i don't know HOW I missed this in the past with all my 
work on the car......

2) that hose which was routed wrong had a BALL BEARING wedged into it to cut 
off vacuum to the advance diaphragm. 

I stumbled across the ball bearing while doing some other work on the car 
(cleaning the motor). when i removed it, the idle increased to about 1000 and it 
ran rough. here are the steps i have taken since then to try to rectify the 
problem.

1) found those two hoses to be routed incorrectly. routed them the right way 
as well as verify correct routing of ALL hoses, including checking to see if 
hoses are on in the right manner on the thermal control valve.

2) checked timing as per shop manual with advance diaphragm hose disconnected 
and plugged from distributor with idle at 775. timing on #6 cylinder 
indicates approximately 12 deg BTC with engine at approx 190 deg F engine temperature 
(according to book, there should be no advance right now when above 104 deg 
F). HOWEVER, when i replace that hose onto the advance diaphragm, i can feel 
that there is vacuum on it (there shouldn't be) and it then shoots up the 
advance on the timing. now with the timing wheel on my light at 0 (not showing 
advance) i can see the timing mark way up at like 50 deg BTC. at this point, the 
car runs smoother and better (when advanced and at idle).

3) started inspecting WHY there is vacuum to the diaphragm when the car is 
hot. checked the idle speed switch. with a meter, i verified that with the car 
not running, the switch does indeed function when activated (checked ohms). 

4) started the engine and with it running and at idle, checked the voltage at 
the electrical connector on the side of the advance solenoid. got a definite 
14.5 volts. this should indicate that the idle speed switch is working 
correctly and it is tripped at the proper times. this should also indicate that 
the advance solenoid, if it is not broken, should be energizing AND should not 
allow vacuum to the distributer advance diaphragm. yet it DOES! 

what has me puzzled is that this would tend to indicate a broken advance 
solenoid. however i replaced this part this summer already (and perhaps i was the 
one who routed those hoses backwards when installing it). i suppose i COULD 
have a defective part, but i got it from Grady and it wasn't a used part. 

also note that when the car is running, it tends to smooth out for a bit, 
then begin to surge a little, then smooth out, etc. the exhaust is very rich, 
too. sometimes when working over the engine it is enough to make your eyes 
water a little. 

what else should i check in order to rule out other possibilities? the only 
conclusion i can come to is that the advance solenoid is broken, but it's hard 
to believe since it is a pretty new part. any other ideas? other tests of 
other parts to do? certainly the problem (or at least A problem) is the 
presense of vacuum at the diaphragm even when the solenoid is receiving 14.5V from 
the idle microswitch. what else could be at fault?

I am at a loss and would like to continue working on this over the weekend, 
so if you have a response, please CC it to my actual email address as well as 
to the list so i can get it right away.

Thanks in "advance" (heh heh)
Andy


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