misfiring 512tr

Check all of the electrical connections in the engine bay and in the fuse panel in the trunk. Disconnect & reconnect them to possibly clean off any oxidation. On the regular TR's there is a thermo-time switch on top of the water gooseneck that can create issues after warm up, does the 512TR have this same component?

 

If it an injector on one side is sticking open or dribbling fuel you might be able to tell which side of the exhaust smells rich and narrow it down a bit. Probably wouldn't hurt to run some injector cleaner / lubricant through the system. Bahr dall use to make a great injector lube / cleaner that absolutely was great stuff .

 

May be prudent to check your engine oil and make sure it hasn't become diluted with raw gas/petrol, and that similarly the level hasn't risen due to gas/petrol cross contamination? John

 

then just check the compression
may be a ring is broken?

 

If it runs fine while it's warming up, I don't think you need to worry too much about. It's probably electrical or the injector.

 

I'm thinking injector had a slight issue. The ethanol gas is hard on everything and just not good gas. I would probably take an ohm meter and check the plug wire resistance value. I might check another wire for a reference value.

 

There is a definite possibility that that injector sticks and stays open, causing smoke and misfiring.
Another possibility is an ECU problem when hot. It should be easily tested - if the problem occurs, disconnect that injector and see if the smoke subsides. If it does, and returns with reattached connector, it will be the ECU. Make sure to get a few tries before condemning either one, the act of releasing the connector might close the sticking injector and lead to faulty conclusions.

 

Is the 512TR's injection system similar to the TR's CIS, ie, "Always on" injectors? They're always spraying; they don't pulse.

Also, blue smoke isn't too rich of a mixture - it's oil. Too rich of a mixture is black smoke. Maybe, when the oil is cold it's thicker, so it's plugging up whatever leak you have (ring as Joe said), and when it heats up, the oil thins out and tada.

 

Do the basics, and check your coils and plug wires, etc. While doing the major on my testarossa I couldn't believe how bad the wires were. They were pretty hardened, and none had continuity...

A bad wire would cause that cylider to misfire...

 

Are you sure it isn't white smoke? Sometimes it's hard to tell. Could it possibly be that you have a blown head gasket? Maybe it doesn't manifest itself until the car warms up and it seeps coolant into the cylinder in question.

That's the only other thing I can think of because blue smoke is not good. The only time you SHOULD get blue smoke is on initial cold startup and it shouldn't take more a second or two to clear out. Beyond that, blue smoke is bad...very bad.

 

check your fuel pressure.