Coreyfatboy Posted March 14, 2016 Share Posted March 14, 2016 Got a 76 Chinook with 20r that has been sitting since 1990. It only has 5000 miles on it and I don't have spark. I have power to the lug on distributor and power at points but nothing to plugs Quote Link to comment Share on other sites More sharing options...
Maineah Posted March 14, 2016 Share Posted March 14, 2016 Do the points open when you turn the engine over? Are the points gaped with in reason? If they are closed with the key on do the points make a small spark if you open them by hand? There is a likely hood that they are just nasty from sitting. The positive post at the coil will have power with the key on if you have power at both posts on the coil then either the points are open or they are not making contact (dirty). Regardless a new set of points/condenser would probably be a good thing. Quote Link to comment Share on other sites More sharing options...
zero Posted March 15, 2016 Share Posted March 15, 2016 22 hours ago, Coreyfatboy said: Got a 76 Chinook with 20r that has been sitting since 1990. It only has 5000 miles on it and I don't have spark. I have power to the lug on distributor and power at points but nothing to plugs I have some old farm tractors that after sitting one winter, need the points filed to get started in the Spring. Points are a high-maintenance item. Easy test is this. Remove the coil wire. Stick a spark-plug wire into it and have a spark-plug at the end of the wire, just laying on a metal grounded part of the engine or body. Then take the distributor cap off. Make sure the points are open. Turn the engine over a little to get them open if needed. Then turn the ignition key "on." Then just short out the points with a screwdriver, off and on. You should see a spark and/or hear a crack - and every time you do that - see a blue spark at the spark plug. If this works -then you can assume all you need is a set of points and condensor. Quote Link to comment Share on other sites More sharing options...
5Toyota Posted March 17, 2016 Share Posted March 17, 2016 I am familiar with the point set up after some time in 1975 they do not use a condenser the points are controlled by the square box mounted on top of the coil it is called the igniter. that may be bad. unless someone has bypassed the igniter and there is a method to do that and installed a condenser. originally in case of it failing you could wire around it and install a condenser. the vintage Haynes books told how to do that. sometimes the coil does fail also. Quote Link to comment Share on other sites More sharing options...
zero Posted March 17, 2016 Share Posted March 17, 2016 Diagnosis is pretty straight forward. For the points and for the igniter. You can short out the points as I already described, or short out the igniter. Quote Link to comment Share on other sites More sharing options...
Coreyfatboy Posted March 18, 2016 Author Share Posted March 18, 2016 New points did it. Now I just have to get carb smoothed out. Thanks for replies Quote Link to comment Share on other sites More sharing options...
zero Posted March 19, 2016 Share Posted March 19, 2016 15 hours ago, Coreyfatboy said: New points did it. Now I just have to get carb smoothed out. Thanks for replies I just had a 1977 carb all apart. Only things I found wrong were two bad accelerator pump diaphrams and a stuck power-valve. Also both choke pull-off pods were bad. If you take your's apart - I suggest you whip out your camera and take lots of photos. This eliminates a lot of guessing later, trying to figure where certain things should go. The kit with all the parts I needed except pods was $18. I got lucky and found new old-stock pods for less then $10 each. Quote Link to comment Share on other sites More sharing options...
Donnie Posted March 19, 2016 Share Posted March 19, 2016 16 hours ago, Coreyfatboy said: New points did it. Now I just have to get carb smoothed out. Thanks for replies The auxiliary pump in these carbs often leak fuel & it gets sucked into the manifold..when it is not supposed to...If you are in a warm climate you can eliminate this pump. But if you are in a colder area it is helpful to get you moving without waiting for your engine to warm up..If you have a rich condition at idle & a bit more black smoke is issued, check this system......it is temp controlled thru a sensor & only works when needed.. As I said before, the diaphragm in these will sometimes leak..it is visible in JD's 3rd photo donnie Quote Link to comment Share on other sites More sharing options...
5Toyota Posted March 27, 2016 Share Posted March 27, 2016 well said I drove my 20R corona many years with the auxiliary pump pluged off . the diafram in those is very prone to failing . I never had any problem. Quote Link to comment Share on other sites More sharing options...
Maineah Posted March 27, 2016 Share Posted March 27, 2016 Yeah Toyota calls it an auxiliary pump but it's really a cold enrichment system controlled by a thermostatic vacuum valve in the water jacket. Quote Link to comment Share on other sites More sharing options...
zero Posted March 27, 2016 Share Posted March 27, 2016 Just works when cold . . . yes - but it is exactly as labeled. Some autos just have one big accelerator pump, whereas the carb on these Toyotas have two. The main accel. pump is adequate for preventing engine hesitation on a warm engine when stomping on the gas pedal. The aux gives a supplemental fuel charge on a cold engine to give an extra raw fuel boost to stop hesitation. I guess it makes the engine a bit more fuel efficient having a two-stage system instead of one big "fits all situations" single state like USA Rochesters, Carters, and Holleys use. And I guess the new Webers use a single-stage system similar to what Holley uses. Quote Link to comment Share on other sites More sharing options...
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