<VV> 1963 Spyder boosts but won't idle:

[Robert Hawley]

Howdy all,

          In early April 2006 I posted to VV regarding my 1963 Spyder - with 24,000 original miles - that would not accelerate past a 32-3500 RPM "wall" and had no boost. It started and idled fine and would drive well with little acceleration and no boost, but could eventually hit freeway speeds.  Thanks to the VV gurus, I got a bunch of possible solutions and forwarded them on to Ken Hand who has had the car since 8/05.  

          He found a small exhaust leak and a ripped accelerator pump diaphragm and has fixed both:  the car will now boost and rev to 6000 RPM "in a heartbeat" (according to Ken), but unless fully warmed up it is nearly un-drivable and Ken has stated that I will not be happy the way it is.  From a cold start (starts fine) it has to idle for at least 5 minutes (200 degrees on the temp gauge) or it hesitates and may stall (restarts immediately).  After a run on the highway using boost it will idle and drive fine with just a slight hesitation off the line.

          The car has a rebuilt carb, rebuilt Turbo, Pertronix 1, Bosch big blue coil, new Spark plugs, Seth's wires, is properly grounded and exhibits good compression consistent with an engine of 24,000 miles.  The car has the original distributor and the pressure retard seems to function properly.  The starter and generator were rebuilt and the original (as far as I know) fuel pump is on it with a pressure regulator - there is no return fuel line on this early 1963 model. Fresh gas was installed and the gas lines and linkage checked.  I have owned this car for over 30 years so I know it has not been abused in that period and it used to run beautifully, though this problem began after the car had sat for several years without being run (it was stored properly).

           Ken is sure that it is a carb issue as the choke seems to work fine.  He has been experimenting using different parts from other YH carbs in my main carb body, but he cannot get the car to boost and idle with the same carb.  On some part mixtures it will idle fine but won't boost and on other configurations it will boost but won't idle.  Ken is now proposing to use the venturi from a LM YH and my YH main body, but it is like guess work and time consuming as the symptoms are only evident when the car is cold.  He has raised the float level above specs and has now set the fuel pressure regulator at 4.5 # to get it to run at this time.  We are both frustrated (it is convertible weather after all!) as he wants the space and I want my car back. 

          The following list was sent to Ken and he has eliminated all of them as possibilities for the problems exhibited.  Sorry for the long post, but any other ideas out there?  Thank you, I am grateful for any suggestions.  Bob Hawley (CORSA/W. Michigan Corvair member)

 

  

POSSIBLE SOLUTIONS <VV>: 

Spark:  Bad Ignition Coil - ignition coil is weak - advance weights installed upside down - frozen (rusted) advance mechanism so the rotor won't move against the advance springs/ weights - incorrect timing curve on distributor - timing

 

Carburetion/Fuel:  Tank contamination - clog in fuel lines - bad fuel filter - plugged fuel tank vent - accelerator pumps that are barely sealing when the car is cold stop working when the carb warms up and the well expands slightly- running lean - misaligned accelerator linkage - air filter - choke not opening all the way - throttle plate not opening fully - the filter at the intake to the pickup in the gas tank may be clogged and/or the fuel pump may be marginal - incorrect fuel pressure - The rod and jet must be matched properly - carb screen is not clear - heat tube under the turbo base is not open to air flow

 

Mechanical/Other: Weak valve springs - turbo not spinning - clogged muffler  -  exhaust leaks - air cleaner filter clogged - insulator pads not attached at the heads under the chrome crossover - Bad coupling hose at the intake/ air leaks around the coupler hose between the crossover and the turbo (OK under vacuum and opening at the start of boost) - make sure the impeller and compressor wheels spin together - check that oil is getting to the center section and that it drains correctly into the r.h. head.  - Engine running too cool to boost - the heads are loose and required retorquing to proper specifications - air leaks at the intake manifold to head gaskets - pressure retard not working (or hose leaks) - leaks at the gasket on the compressor side of the turbo hosing - incorrect gaskets anywhere in the turbo system