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Old 11-07-2009, 07:29 PM
a5a1234 a5a1234 is offline
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Join Date: Jul 2007
Location: Vancouver, BC, Canada
Posts: 45
Many thanks to GGR, Tomguy and Graham for their very helpful comments.

I had to wait until today to get some time to work on the car. Here is my progress report...

1. Air idle valve - when screwed all the way in, the engine slows, but does not stall.

2. MAP Sensor
Holds at least 20" vacuum. This dropped to 17" after 4 minutes, but I hadn't hose-clamped the connection to the MityVac.

Resistance between terminals 7 & 15 = 91.5 Ohms
Resistance between terminals 8 & 10 = 331 Ohms

More below

3. Timing
At idle, with vacuum connected at distributor, timing is 5 degrees ATDC.
At idle, with vacuum disconected from distributor (and plugged), timing is 10 degrees BTDC (just to be sure I am not reading the dial incorrectly, the pointer was indicating to the LEFT of the zero mark with vacuum connected, and to the RIGHT of the zero mark with vacuum disconnected & plugged).

Vacuum measured at the distributor (using vacuum line disconnected from distributor), is 15" Hg (therefore 10 degrees BTDC).

Vacuum measured at the line coming from the manifold, to connect to central locking = 10" Hg.

4. TPS
I did not have time today to dismantle the TPS and service it as described, but I did try a couple of tests.
With ignition set to "on" but engine not running, I was able to move the throttle manually from closed to fully open, and counted 20 clicks as the injectors cycled.

I attempted the test where voltage is measured at terminal 17 of the TPS connector, and a 0.016 in feeler placed between the throttle stop and the the throttle. I couldn't get the test to work - there is supposed to be voltage (with ignition on) when the feeler guage is in position, and no voltage without the feeler guage. I couldn't get any voltage at any time. I assumed that I had to "piggy-back" onto terminal 17, and compare with car ground. Is this correct?

5. A question about MAP adjustment
I had a close look at my MAP sensor today. I have read in several places that there is a hex screw that is to be adjusted (1/8th turn at a time). I cannot see any hex screw on my MAP sensor. When looking at the end opposite the electrical connector and sensing port, there is a hole where the "epoxy covered Full-load Stop Screw" (Paul Anders' web-site http://members.rennlist.com/pbanders/manifold_pressure_sensor.htm) should be positioned. This has been removed, which I understand was often done. However, I seem to have a clean cylinder there, with a small cylindrical hole at the bottom. I can't see anywhere to make any adjustment with a hex key, should this be needed. Has something "crazy" been done to this MAP sensor? I tried to snap a picture, but it is quite difficult to get a shot of the interior of the screw hole.

Joe
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