Warm-up setup for a stock Ljet motor? Options

[computers4kids]

Looking for a picture or description how the thermostat is connected to the throttle body of a ljet motor (maybe the same a djet setup). What other components are involved in the warm-up circuit of a ljet motor?
Thanks...if you got a picture, all the better.
Mark

[Dave_Darling]

Oh, it's easy. The throttle body is bolted to the engine, and so is all of the warm-up stuff. That's the only connection between them.


....Oh, a real answer? OK, let me try...

There is the cold-start valve. It is, contrary to what lots of references will tell you, not a part of the warm-up stuff at all. It is merely to help the engine get some extra fuel while the starter is cranking so it can light off easier. It is run by the starter circuit and the thermo-switch (or thermo-time switch on the 1975 1.8s).

There is the head temp sensor, in the head near the #3 spark plug. It tells the ECU to make the mixture richer when the head is colder.

Finally, there is the Auxiliary Air Regulator. This is what keeps the engine from stalling at idle when it is cold. It acts as a bypass to the throttle, in much the same way that the idle passages in the throttle body do. But this is a separate part, up to the left-front (I think???) of the manifold. It has one vacuum hose that connects to the manifold, "downstream" of the throttle valve, and one that connects to the intake boot, "upstream" of the throttle valve. When the AAR is cold, it lets lots of air go through it, bypassing the closed throttle. When the AAR warms up (and there is a heating element in it to make sure it warms up), it closes so that it doesn't let any air go from upstream to downstream.

That's pretty much it. I don't think the 74 1.8 has an intake air temp sensor (the 75 does), but that isn't exactly part of the engine warm-up part.


OK, one other thing that has nothing to do with the fuel injection: There is a thermostat on the bottom left side of the engine, shaped like an accordion. When it is cold, it pulls on the wire attached to it, which pulls the flaps inside of the engine tin to the "warm this engine up please" position. When the t-stat warms up, it expands, and the spring on the flaps cross-shaft pulls the flaps into the "maximum cooling now" position.

And the latter system is what we usually mean when we talk about a thermostat in a 914. But it's not fuel injection related, other than being bolted onto the same engine as the FI system.

--DD