My TR4A is running poorly and I am looking for some of you that are smarter then me to help me out. For background, the engine has only 800 miles on it since I rebuilt it (head to machine shop for new valves and seats, all bearings in the engine new, crank ground, cylinders honed and new rings). The carbs (HS6) were rebuilt and have new jets (0.100 inch) and new needles (standard TW). The thermostat is the 160-degree F. one. The entire ignition (coil, plugs, cap, rotor, points, condenser and ignition wire) is new (again this week). The plugs are NGK BPR6HS. The timing is set to 4 DBTDC static (but see my question below about this). Compression is good on all four.
The symptoms are: at idle it seems rich (when I do the lift the dash pot test I have to lean the carbs all the way before the engine responds the way the book says it should for the correct mixture. But, when I drive the car and accelerate hard the engine acts as if it is too lean (it misses and has no power, but if on hard acceleration I then pull the chock it runs a bit better). Also but, over all it is running very rich, in that it uses a lot of gas (compared to my TR3A with the same engine) and the exhaust is very black (in fact the back of the car is covered with black soot).
My questions are many but can be summarized into one. Does any one have any ideas what is up with this engine? One at a time they are: How does timing interact with apparent mixture (that is if my timing is way off can this make the mixture look right when it is wrong)? Can the cool 160 thermostat cause it to need to be too rich? In the Haynes manual it says to rotate the distributor counter clockwise when setting the timing but the rotor turns CCW as well so should the static timing not be set by turning the distributor clock wise until the points just start to open? Also in the Haynes it says to set the vernier one division mark on the distributor advance. I notice that the fourth mark is longer, so is ‘one mark’ four small ones (to the first long one) or just one small mark?
Any help would be much appreciated. This problem has been with me since last fall but I gave up on it then and put the car away for the winter and did not touch it again until yesterday when I replaced the entire ignition and started it up for the first time since last November.
The symptoms are: at idle it seems rich (when I do the lift the dash pot test I have to lean the carbs all the way before the engine responds the way the book says it should for the correct mixture. But, when I drive the car and accelerate hard the engine acts as if it is too lean (it misses and has no power, but if on hard acceleration I then pull the chock it runs a bit better). Also but, over all it is running very rich, in that it uses a lot of gas (compared to my TR3A with the same engine) and the exhaust is very black (in fact the back of the car is covered with black soot).
My questions are many but can be summarized into one. Does any one have any ideas what is up with this engine? One at a time they are: How does timing interact with apparent mixture (that is if my timing is way off can this make the mixture look right when it is wrong)? Can the cool 160 thermostat cause it to need to be too rich? In the Haynes manual it says to rotate the distributor counter clockwise when setting the timing but the rotor turns CCW as well so should the static timing not be set by turning the distributor clock wise until the points just start to open? Also in the Haynes it says to set the vernier one division mark on the distributor advance. I notice that the fourth mark is longer, so is ‘one mark’ four small ones (to the first long one) or just one small mark?
Any help would be much appreciated. This problem has been with me since last fall but I gave up on it then and put the car away for the winter and did not touch it again until yesterday when I replaced the entire ignition and started it up for the first time since last November.