SPICA clockwork

Once the car came back from Mike’s, it was a little hard to start, but ran great once it warmed up a little.  This is due to the fix for the Thermostatic Actuator (TA).  Here’s a pic of the topside of the fuel injection pump:

What you are looking at are the brains of the system.  At the bottom is the cold start solenoid that only actuates when the starter is running.  I think it just dumps as much gas as it can.  Above and to the right is my “new” TA.  It’s just an old TA with a bolt threaded into the top.  The stock TA uses expanding fluid in a tube from the block to press the same piston that the threaded bolt depresses.  When the engine is cold, the piston is released and the mixture is richened.  As it heats up, the piston gets depressed and the mixture leans out.  This is fine until the tube breaks and you are running rich all the time.

This is basically what was causing my idle to be 2000-3000 rpm.  Rebuilt TAs are available for $350 or so, but Mike had the alternative from another job and we decided to try it out.  The bolt is set to the hot setting, so cold starts take awhile.  Once just a little heat develops, however, it runs fine.

Above and right of the TA is the gas shut off solenoid and mixture setting valve (yes, combined!).  The shut off solenoid is for deceleration to avoid backfire.  Finally, the device with the lever arm is the barometric compensator that is adjustable for starting temperature.

So the entire SPICA injection pump is really a mechanical computer with several clever mechanical sensors.  Only the Italians!!




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