by marco_1978_spyder » Sun Jun 06, 2010 10:49 am
So...
I pulled the carb off.
I pulled the float bowls and checked things out.
I retightened the rear metering plate. and reassembled, everything else was ok.
I set both throttle plate stops so that the transfer slot looked like a little squares on both primary butterflies and Secondaries. Probably .030 max.
The actual idle speed screw (no not the mixture screwS).. was left backed almost completely out.
I re installed the carb and reset the floats.
Idle speed was @ 1,100.
I used the throttle stop on the secondaries to adjust the idle speed... I brought it down to 700 rpm.
Reset the floats, reset the timing back up to @ 16 advanced . Reset the idle (using secondaries) and floats and timing a few more times.
Finally... the exhaust seemed to clear up and the car would die once again with the idle mixture screws turned all the way in.
So I backed those out for max vacuum which parked around 17hg. And a more steady needle than before.
Engine sounds decent and pulls nicely to 5k. rpm.
-BUT-...The damn Idle bucking...flat spot, and surging in cruise are all still happening!!
Now I want to pull the manifold and do an inspection (Been through the dizzy already)
I'm hoping to find out I have a bad intake gasket seal. But I have the feeling I'm going to tear the manifold off only to find everything looking normal.
I wonder if an aging drivers side engine mount could be a culprit... My theory there is, some of the engines power is being used to lift the engine up an inch or 2, until it falls back under its own weight.
1978 Monza Spyder V8 4speed, posi
1978 Sunbird Formula V6, 5 Speed, Hatchback
1980 Sunbird Hatchback 4cyl, 4spd.
2006 Chevrolet Aveo 5 speed Hatchback
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