Brohemius Posted March 7, 2015 Report Share Posted March 7, 2015 So I took the plunge into the world of Datsun, And so far i love it. Got this 1981 720 from denmarkboy at a fair price. Having some rough idle and major stalling issues so I replaced all the vacuum lines. This is before, i forgot to take a photo farther to the right. New lines New lines installed. And heres all the crusty old line that was removed. While initially inspecting the vacuum lines i found this open nipple that i have no idea what is for... I cant find any open lines or another nipple that i should connect it to with line. Any help on that would be great. And lastly, the truck is having some strange stalling issues. On some days everytime i pop the clutch in or put it in nuetral or even at a dead stop idling, the engine stalls or i have to feather the throttle for it to stay running. Ive messed around with the idle control screw to keep it idling barely higher so it doesnt die, but to no avail. Im not sure what would cause this, maybe carb related? It is running very rich... lots of help from Rhino13 today. Thanks brother. Glad to be a part of this forum! Will update with an engine bay cleaning soon. 4 Quote Link to comment
Fat510 Posted March 7, 2015 Report Share Posted March 7, 2015 Welcome aboard :) 1 Quote Link to comment
denmarkboy Posted March 7, 2015 Report Share Posted March 7, 2015 Nice start to your thread , i cant wait to see it at canby ! 2 Quote Link to comment
wayno Posted March 7, 2015 Report Share Posted March 7, 2015 I would plug off the open fitting, see if it changes anything. 2 Quote Link to comment
arizonajones Posted March 7, 2015 Report Share Posted March 7, 2015 Welcome! Denmarkboy is the right guy to buy a Datsun from. Congrats. Can you get some more pics of the stuff around that open spot? Good call on replacing all the lines. It sounds like a vacuum leak if its running rich and still stalling. Find out what's supposed to plug that end (or plug it and see if that fixes your idle) if it doesn't you can put a hose in you ear and use the other end to listen for hissing around the connections. 2 Quote Link to comment
Lockleaf Posted March 7, 2015 Report Share Posted March 7, 2015 If the truck sat fire any length of time, sea foam it or carb clean it. I have one that sat all winter, ran fine before but does that now. I seafoamed it a little which helped, but I think it needs more. And new gas. 1 Quote Link to comment
Brohemius Posted March 7, 2015 Author Report Share Posted March 7, 2015 Thanks for the warm welcome everyone! So i plugged that open hole with my finger and i could instantly hear it run better. Going to get a line plug in about 20 mins. If it has that much effect on the engine should it be going to something? Or does that tell me its supposed to be plugged? Ill put up more photos later today jones. update soon with a drive report also, after plugging it and driving around a bit. Lockleaf i have a can ready to use, i have heard great things about seafoam and i have heard lots of bad also. What do all you datsun vets say about the foam? And if i were to use it what vacuum line feeds all cylinders most evenly? Most people use the brake booster line, but i wasnt sure if that is the best line for this engine. 2 Quote Link to comment
datzenmike Posted March 7, 2015 Report Share Posted March 7, 2015 While initially inspecting the vacuum lines i found this open nipple that i have no idea what is for... I cant find any open lines or another nipple that i should connect it to with line. Any help on that would be great. I believe that connects to the vacuum motor in the air filter snorkel. It's a gate that mixes cold and warmed air from the exhaust manifold controlled by a temp sensor in the air filter that regulates it. Easily pulled off when removing the air filter housing. 2 Quote Link to comment
arizonajones Posted March 8, 2015 Report Share Posted March 8, 2015 DMike's on it, as always. I just found this batch of pictures on another forum where you can see where it connects to the air filter housing: http://forums.nicoclub.com/idling-problem-t517146.html 2 Quote Link to comment
Lockleaf Posted March 8, 2015 Report Share Posted March 8, 2015 I always just use the vacuum booster line like you said. I also just slowly pour it down the carb while the truck is running. When it starts to stumble and tries to die, stop and let it ruin till it rubs smooth again, then start pouring slowly again. I've used it for years, never had a complaint. I've also been selling it across the parts counter for 8 years and sold hundredsf if not thousands of cans. I've had one guy complain and many guys thank me for the recommendation, for whatever you think that is worth. 1 Quote Link to comment
Brohemius Posted March 8, 2015 Author Report Share Posted March 8, 2015 So i seafoamed the old beast. It smoked like crazy... And now runs a little smoother. Gonna do it again in a few days. The stalling issue has stopped, for now atleast. Gonna replace all plugs and check the distributor cap and probably replace it also. Basically gonna do a full tune up bit by bit. The only other issue at the moment that is concerning is a "chuggy" feeling tranny. When cruising in 2nd or 3rd at a constant speed i get a slight chug. Kinda jumpy feeling. Maybe its just trying to regulate and barely applying throttle in bursts? 1 Quote Link to comment
ryanthomas1 Posted March 9, 2015 Report Share Posted March 9, 2015 If equipped with an auto trans check the vaccum actuator , or throttle cable to the trans, (if so equipped) this will engage the TCC (torque converter clutch and cause a rich condition in some, and stall the vehicle out). Idk if Datsun added a TCC yet at this point so I may be full of crap, but just somthing I've leanrned with this. Also, fuel filters in these trucks of age get dirty, there is one in the pump itself you can clean , and another outside. It is located just infront of the passenger rear wheel on the frame under a cover plate. 1 Quote Link to comment
Brohemius Posted March 10, 2015 Author Report Share Posted March 10, 2015 Its a manual trans. I really want to take care of the dieseling as it happens 95% of the time when i shut it down. Not sure what to do about it. I guess its running rich and thats the problem? 1 Quote Link to comment
arizonajones Posted March 11, 2015 Report Share Posted March 11, 2015 Its a manual trans. I really want to take care of the dieseling as it happens 95% of the time when i shut it down. Not sure what to do about it. I guess its running rich and thats the problem? Check your anti-dieseling solenoid on the carb. Make sure the wires are properly connected & make sure the fuse is good. Also, w/ engine off, turn the key to engage the battery (but don't start it) and listen for a click in your carb - that's the solenoid. Last, unscrew the solenoid, clean out any gunk in the hole on the carb and/or inside the solenoid, and make sure there is a spring and a needle inside it. If still dieseling after that, lean it out and make sure your timing is right (could be too far advanced.) 1 Quote Link to comment
Scurrvy Posted March 11, 2015 Report Share Posted March 11, 2015 Mine did that for a bit then I had to tinker with the carb and it finally stopped, used to back fire pretty bad too. The blue wire on mine has been cut, thinking of re attaching it to see if the choke still works, just haven't gotten around to it yet. Quote Link to comment
Brohemius Posted March 14, 2015 Author Report Share Posted March 14, 2015 I seafoamed it again and the dieseling has diminished but still happens. Just less extreme and not as frequent. Im going to clean the engine bay soon and repaint all the accents as close to the original blue as i can. Also gonna paint the valve cover im just debating if i should match it to the light blue accents or do red to match the truck. Also gonna do new plugs, fuel pump and filter, air filter, and anything else i can think of. Also gonna rebuild the carb soon. I want 30mpg lol!! Quote Link to comment
Brohemius Posted March 16, 2015 Author Report Share Posted March 16, 2015 Ok went to get an alignment today and discovered some issues. The idler arm bushing is gone, as a result im guessing the idler arm is warped from being used without a bushing. And i found this major rubbing going on behind the idler arm. Heres a view from the top where the bushing rubs. So now to get some new bushing and maybe an idler arm... And to make that section not rub. Also what is this little connector called? I need a new or lightly used one. Quote Link to comment
Brohemius Posted March 17, 2015 Author Report Share Posted March 17, 2015 Ok so i ordered a bushing set for the idler arm, and also a left outer tie rod. Hopefully the bushings even that arm in the back and it doesnt rub. Pictures of the fun coming tomorrow! Quote Link to comment
wayno Posted March 17, 2015 Report Share Posted March 17, 2015 I would just buy a new idler arm myself. Also I would loosen the bolts holding the idler arm and see if you can get the arm to drop a little by twisting it down on the end of the idler arm, it's tight there on my 720, but not that tight. Ok so i ordered a bushing set for the idler arm, and also a left outer tie rod. Hopefully the bushings even that arm in the back and it doesnt rub.Pictures of the fun coming tomorrow! Quote Link to comment
Brohemius Posted March 18, 2015 Author Report Share Posted March 18, 2015 So today i dealt with the major front end issues. Atleast for a week or so until i can get a new idler arm and wheel bearings and tie rod ends. Showing the melted bushing again. I was able to just pull the bottom bolt off and then slide the outer collar off without having to take the entire idler arm assembly off. (cleaned the shit off also) Inside view of the idler arm collar. New bushings installed and all greased up inside. The bushings evened out the rub and it looks to just barely clear now. 4 Quote Link to comment
Brohemius Posted March 19, 2015 Author Report Share Posted March 19, 2015 Can anyone tell me what this is called? I need to source a better one. This one is gonna crumble if unplugged. 1 Quote Link to comment
Rhino13 Posted March 20, 2015 Report Share Posted March 20, 2015 Cruised out to the pacific ocean today! 2 Quote Link to comment
Charlie69 Posted March 20, 2015 Report Share Posted March 20, 2015 The picture "Whats this" is the AC pressure switch. The part that is rotten is the boot for the plug. If AC works then it is not broken. Quote Link to comment
Brohemius Posted March 20, 2015 Author Report Share Posted March 20, 2015 Thanks charlie!! The ac does indeed work i just want to find a boot in better shape. last time i unplugged that one 20% of it turned to dust. And i want to wash my engine bbay, so i want my connections to be water resistant atleast. Also thank you to everyone else who posted advice for me! Very very much appreciated! Trip to the coast yesterday. 3 Quote Link to comment
Brohemius Posted March 20, 2015 Author Report Share Posted March 20, 2015 A problem has appeared in the last two days. WWhen i leave the truck for a few hours sometimes it wont start or even turn over, just a "click" sound that i havnt found the source of. But if i try to start it in rapid succession, as in turn the key "click" turn it back and turn it again and repeat like 5 or more times quickly. If i dont do it quickly it doesnt do shit just the "click". It seems the rapid on and off of the key is what helps... Please help as this one worries me. ive had alot of hell with starters in the past and my mind instantly thinks starter. 1 Quote Link to comment
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