cartell Posted July 1, 2006 Share Posted July 1, 2006 Can anyone help with the following problem on my 87 ‘L’ series S/wagon, 1800 (non turbo): From reading the workshop manual, there are two main parts that affect the operation of the automatic electric choke on Hitachi Carburettors. Heres what I know about these parts: 1. HEATER ELEMENT & BI-METAL SPRING: Heat generated by the heater element under the bi metal spring in the choke housing causes this bi metal spring to contract and rotate the choke lever, thus gradually opening the choke valve as the engine warms up. 2. AUTO CHOKE SOLENOID: Directly underneath the black round choke housing is a solenoid(?). This solenoid is supplied with 12Volts on start and run (the same 12Volt supply also powers the heater element in the choke housing on start and run). I can see what this solenoid is supposed to do - by way of a set of small linkages that push a small rod, its job is to ensure that the choke valve stays in the open position once the motor warms up. It would appear that this solenoids ability to operate is dependant upon the heater element/bi-metal spring having had sufficient time to warm up and begin opening the choke valve - only then can the solenoid work. HERES THE PROBLEM: On my car this solenoid doesn't seem to be doing anything, and hence the choke valve is staying slightly closed when the motor has fully warmed up. If I push the small solenoid operated rod by hand (this is the rod that goes into the auto choke housing, and forces the choke valve open), it opens the choke valve fully and the car runs properly. There is 12 Volts getting to the solenoid, and the solenoid coil reads 3 ohms (thought this was bit low for a coil?). I figure that if there is power to the solenoid coil and the coil reads 3 ohms, it should operate and push the small rod and this is what I don't understand. The heater element/bi metal spring is working fine and opens the choke about 75%, as the motor warms up but why isn't this solenoid doing its job and opening the choke valve fully? Can someone verify what this solenoid is supposed to do, what might be wrong with it and how to fix it? Also, at what position should the choke valve be in when the motor is stone cold – fully closed, or slightly open? Link to comment Share on other sites More sharing options...
85Sub4WD Posted July 1, 2006 Share Posted July 1, 2006 you should be able to rotate the plastic choke housing, to adjust the degree/time to which it opens - play with it a bit and you'll see the choke should not usually be fully closed when cold (but mostly closed), it SHOULD be fully open when warm - hope this helps the solenoid you are looking at keeps the engine from "dieseling" or chugging after you shut the car off - it has no effect on the actual choke - there is another solenoid on the carb for purging the EVAP canister, but it is on another part darn - sydney - differnt than US carb - take the part about the solenoid with a grain of salt, but adjustment should be the same - for the bi-metal spring Link to comment Share on other sites More sharing options...
cartell Posted July 1, 2006 Author Share Posted July 1, 2006 In reply to 85Sub4Wd, thanks for your help - whilst you where replying I went and played with the choke for a while - and then it all came clear. I adjusted the black plastic turnsytle, and did up the screws. I'll wait until the motor cools down over night then have another crack at it in the morning. That anti chug device still baffles me, and I wonder if that EVAP cannister is like the boost bottle I had on my old 2 stroke Yamaha IT200, but I'll get over these issues after the first beer (5am Sat night here). Oh, and yes, our carbs are different down here - they are designed to work upside down. Cheers, Dave Link to comment Share on other sites More sharing options...
()__1337_CRAYOLA__()> Posted July 1, 2006 Share Posted July 1, 2006 Oh, and yes, our carbs are different down here - they are designed to work upside down. Link to comment Share on other sites More sharing options...
dxrflyboy Posted July 1, 2006 Share Posted July 1, 2006 Oh, and yes, our carbs are different down here - they are designed to work upside down. Cheers, Dave Is that it? Or is the air/fuel mixture designed to "swirl" in the opposite direction through the barrels? Link to comment Share on other sites More sharing options...
cartell Posted July 2, 2006 Author Share Posted July 2, 2006 Is that it? Or is the air/fuel mixture designed to "swirl" in the opposite direction through the barrels? Interesting, I'll think about that while I have a bath tonight... Link to comment Share on other sites More sharing options...
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