Heater connection to exhaust manifold - B200E

[kelvingenders]

Just tried to connect the heater tube to the exhaust manifold on the B200E and the nut keeps getting mis-threaded. I has noticed that there is a bush on the end of the tube for sealing purposes. Is the nut mean't to tighten write down or is this mis-thread a design feature? Ideas

[Ride_on]

You have a heater tube on an exhaust manifold?? The carb cars have a pre-heater for carb icing, didn't think the injection cars had one?

[Nimminz]

Aye mine has one, with a thermal valve thing on the bottom of the airbox.

Afraid i can't help with your problem though mate, never took the thing off mine

[macplaxton]

No experience of this specific case, but mis-threading doesn't sound like good news to me.

[Ride_on]

What does an injection need hot air for? My more modern 940 doesn't have one and I fairly sure my 87 GLT didn't have one. Am I missing something?

[Chris_C]

Your 940 has closed loop intelligent injection though. The 360 system is epically primative and doesn't have either a water temp sender (from memory) or lambda to know how hot the engine is as to when to vary the fuel put in. The flappy paddle may be crude, but the bi metallic strip works enough to keep everything almost right all the time.

[kelvingenders]

We are talking about a small metal tube that runs from the manifold...nearest the firewall to the heater. shall i provide a picture... then everyone will be happy?

[Ride_on]

Your 940 has closed loop intelligent injection though. The 360 system is epically primative and doesn't have either a water temp sender (from memory) or lambda to know how hot the engine is as to when to vary the fuel put in. The flappy paddle may be crude, but the bi metallic strip works enough to keep everything almost right all the time.

Ah Looking at the Haynes manual I see it now, same as the carb, must be to do with emission controls trying to manage the varying air temp coming in as the car has a air volume meter rather than an air mass meter. These pipes are often missing and air measurement technology has improved in later cars along with computerised injection mapping so they don't have them. In carbs it will cause you severe problems in some conditions, but injections just a little economy or performance damage.

BTW the 360 B200E has a thermal time switch that switches on an extra injector for really cold starts, that last only a sort period. Modern cars just enrichen the mixture with software (computerised injection control) and a temp sensor. Lambda feedback is too slow for real time closed loop control, its really a replacement for the adjustment, but it useful for things like altitude changes, hence injector output is memory mapped to air mass and throttle position in a non-closed loop fashion with Lambda providing a slow closed loop feedback adjustment.

Anyway Sorry for the distraction, probably mixing up my different cars 940s etc.