Emilio's79620 Posted November 7, 2015 Report Share Posted November 7, 2015 So on my 78 620 the headlights have a weird thing going on, the left side is fine it's just the right. When I turn my lights on both far lights come on but when I put the beams on,the far right light shuts off and the center right light comes on?? Also the little circle the blinkers are attached to moves forward and backward it moves the whole plastic column piece left and right when I turn my blinkers on Quote Link to comment
datzenmike Posted November 7, 2015 Report Share Posted November 7, 2015 The far right Hi/Low headlamp has a burned out Hi beam filament. The turn signal assy is heed onto the steering column with a clamp tightened by a screw. Probably just loose. Quote Link to comment
Emilio's79620 Posted November 7, 2015 Author Report Share Posted November 7, 2015 Mike your the plug Quote Link to comment
datzenmike Posted November 7, 2015 Report Share Posted November 7, 2015 is that good or bad? Quote Link to comment
datzenmike Posted November 7, 2015 Report Share Posted November 7, 2015 Swap the outer two headlamps. If the problem switches sides the headlamp is bad. If it starts working, the plug may have been loose or corroded. Quote Link to comment
Emilio's79620 Posted November 7, 2015 Author Report Share Posted November 7, 2015 Plug!? Meaning like you have something for everything... It's a good thing Quote Link to comment
Emilio's79620 Posted November 7, 2015 Author Report Share Posted November 7, 2015 Gotcha thank you mike also I don't know if I should start a new topic or just ask you here? So now that my truck is ok for the most part but anyway when I turn the truck on it dies out after a minute or two of idling but if I put like my hand or a rag (no air filter on this carb)over the barrel it stays on and continues to run..I bought the truck without a complete carb but I do have a whole other hitachi so I could put any missing piece my from the 79 carb to my 78 (truck without a complete carb) my 79 has a Webber so I have no need for anything from the hitachi Quote Link to comment
Emilio's79620 Posted November 7, 2015 Author Report Share Posted November 7, 2015 What I was asking is do you think that's all it needs is the air filter or some adjusting if I have to adjust what do you recommend Quote Link to comment
datzenmike Posted November 7, 2015 Report Share Posted November 7, 2015 Is this a cold start up? If yes, is the choke on? Quote Link to comment
Emilio's79620 Posted November 7, 2015 Author Report Share Posted November 7, 2015 I guess it would be seeing how it has been started for awhile.... But if it does this when warm what would be the problem also how would I get it warm if it continually dies after start up? Just keep giving it gas? Quote Link to comment
datzenmike Posted November 7, 2015 Report Share Posted November 7, 2015 When working properly, if you take the top off the air filter on a cold engine the carb should look like this with the choke open or part open... Step on the gas once, the choke flap should close like this... . Quote Link to comment
Emilio's79620 Posted November 7, 2015 Author Report Share Posted November 7, 2015 So when it closes it'll keep it idling? Quote Link to comment
Emilio's79620 Posted November 7, 2015 Author Report Share Posted November 7, 2015 Also thank you again mike Quote Link to comment
datsunaholic Posted November 7, 2015 Report Share Posted November 7, 2015 If it starts cold then dies as it warms up, you probably don't have the idle cut solenoid hooked up. It's idling on the main jets when cold (since the choke being closed also kicks the throttle open slightly). When the throttle shuts (and the choke opens) as it warms up, it transitions entirely into the idle circuit. If that's closed (because the idle cut solenoid isn't being powered), it'll go lean and die. Putting your hand over the carb acts like an additional choke so it'll run a BIT longer as it warms up, but it still won't idle when fully warmed up. Get the idle cut solenoid working and you'll probably find that it'll idle too fast. I've seen a lot of folks try to adjust the idle when the idle circuit was dead, which screws up everything. Quote Link to comment
datzenmike Posted November 7, 2015 Report Share Posted November 7, 2015 The above too.When cold, engines are not efficiently vaporizing the fuel drawn into them. Raw gas droplets won't burn, they need to vaporize to mix with the air. Warm intake and air, warm head ports and valves and hot combustion chamber and piston tops all contribute to fuel evaporation. To help avoid poor cold running, a choke is used to make the fuel mixture richer. As Doug mentioned above your idle cut solenoid may also not be working. This is a mechanical shut off device to stop fuel flow to the idle circuit when the ignition is shut off to prevent dieseling or 'run on' when hot. This is fine when the engine is cold and the choke is on masking it's absence, but as the engine warms up there isn't any fuel getting to the idle and it quits. The Idle cut solenoid is a hexagonal shaped object on the rear right side of the carburetor with a single Red wire to it. (may have a Black covering over the Red) If you turn your ignition on off, on off (not start) you should hear a soft clicking sound from the carb. Quote Link to comment
Emilio's79620 Posted November 10, 2015 Author Report Share Posted November 10, 2015 Mike was there a difference between the 78/79 carbs because the carb off of my 79 has a lot more on it than my 78 Quote Link to comment
taeroplane Posted November 10, 2015 Report Share Posted November 10, 2015 I have a January 1976 620. The low beams work but the high beams are on all the time. Also need some help figuring out how to put the blinker system back together. I bought the truck in rough shape electrically. The blinker assembly is for a 76 but the plug in is not the same. The old pigtail has 8 wires and the installed one has 7 and the connection is a different format. Where do I find a correct wiring diagrams? Is there more than one blinker unit? one for hazards and one for blinkers? I will have more questions I'm sure. Thanks for the help Quote Link to comment
datzenmike Posted November 10, 2015 Report Share Posted November 10, 2015 Every year the emissions levels are lowered and many new things were tried and added. The California trucks were even worse. The carb is basically the same with small ad ons and different settings. It might be for a California truck? It would have a float chamber vent hose to the charcoal canister. The '79 and up 620 and 720s had a fuel shut off system during high RPM deceleration. Actually saved gas. Lots of small delays built into vacuum lines. Quote Link to comment
datzenmike Posted November 10, 2015 Report Share Posted November 10, 2015 I have a January 1976 620. The low beams work but the high beams are on all the time. Also need some help figuring out how to put the blinker system back together. I bought the truck in rough shape electrically. The blinker assembly is for a 76 but the plug in is not the same. The old pigtail has 8 wires and the installed one has 7 and the connection is a different format. Where do I find a correct wiring diagrams? Is there more than one blinker unit? one for hazards and one for blinkers? I will have more questions I'm sure. Thanks for the help taeroplane... This is someone else's thread about their headlight problem. Two people asking for headlight help on the same thread could easily become very confusing. Just so you know next time, if you have a problem, start your own post on it, then all answers are yours. The hi and low beams are selected by the turn signal stem. If you are having compatibility problems with your turn signal switch then this is the first place to look. Sometimes the plugs changed for different years but a '76 should fit a '76. One of them isn't a '76 then. Maybe the wiring was changed on the steering column or the '67 switch isn't a '76. Where is the original turn signal??? Wiring diagrams here...http://www.davidcmurphy.com/olddat//data/dat620-1976.pdf look under 620 TECH near bottom of page There is a flasher unit for the 4 way emergency lights and a separate flasher unit for the left and right turn signals. Quote Link to comment
taeroplane Posted November 10, 2015 Report Share Posted November 10, 2015 Thanks for the info and I will start my own topic.. Quote Link to comment
datzenmike Posted November 11, 2015 Report Share Posted November 11, 2015 Be sure to include lots of pictures of your 620. Quote Link to comment
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