Nell Posted November 21, 2011 Report Share Posted November 21, 2011 I'm writing this from phone so I'll do my best to explain. I'm a new Datsun owner, I have a 1980 Datsun 510, all stock with 82,xxx miles. I was driving it for about 3 weeks and then I had trouble getting it stared then eventually I couldnt get to idle very long. I'm not to familiar with cars this old. I had changed fuel filter and I had also tested fuel pump, gas squirts from hose when cranked. I sprayed carb cleaner on the carburetor, still nothing, then I even tried adjust the idle speed screw? And fuel mixture screw? It was working for about a day then same problem occurred . Then I found a vacuum hose from distributor that split one way into the carb and the other just appears to go no where , looks like it broke from something. I'm thinking leak? So I plugged that hole and it started up and seemed slightly better , it idles but not smooth. The moment the hose is unplugged i, the car stalls . I'm no mech , but I'm handy with tools , I would appreciate all the help I can so can get my Datsun running smooth again Quote Link to comment
Phlebmaster Posted November 22, 2011 Report Share Posted November 22, 2011 Welcome to the forum..... :-) First off, it sounds like you are trouble shooting this yourself just fine. Do you have a specific question you are looking to answer? Take a gander at what others have posted related to a specific issue by using the search function. That will bring up threads related to what you are trying to resolve. Quote Link to comment
Nell Posted November 22, 2011 Author Report Share Posted November 22, 2011 I can't get it to run Quote Link to comment
datzenmike Posted November 22, 2011 Report Share Posted November 22, 2011 Look under the hood for the emissions label. Does it have the vacuum hoses displayed? If so try finding them and follow looking for other splits or missing ones. The vacuum line to the distributor shouldn't have any vacuum at idle... makes me think that someone has mistakenly hooked it to manifold vacuum and then had to adjust the timing back. Now when vacuum is removed it stalls. Quote Link to comment
Nell Posted November 22, 2011 Author Report Share Posted November 22, 2011 I can't get it to run , where does this vacuum line go Quote Link to comment
Phlebmaster Posted November 22, 2011 Report Share Posted November 22, 2011 Look under the hood for the emissions label. Does it have the vacuum hoses displayed? If so try finding them and follow looking for other splits or missing ones. I can't get it to run , where does this vacuum line go You said you had it running..although not well in your original post. Follow Mike's advice and look for the vacuum diagram that is usually somewhere under your hood. If not, then try looking for a diagram online or even purchase a service manual if you cannot find one online. Quote Link to comment
king bee66 Posted November 22, 2011 Report Share Posted November 22, 2011 how does something stay started? Quote Link to comment
datzenmike Posted November 22, 2011 Report Share Posted November 22, 2011 I'm a new Datsun owner. I'm no mech , but I'm handy with tools , I would appreciate all the help I can so can get my Datsun running smooth again We all have to start somewhere. ;) Quote Link to comment
datzenmike Posted November 22, 2011 Report Share Posted November 22, 2011 We all have to start somewhere. ;) In invaluable tool for diagnosing is being able to post on line pictures. If you don't have a FREE Photobucket account, get one and follow the info. I've seen pictures show something totally different from what the owner thought he had. Very helpful to be there and see what he sees. Quote Link to comment
Nell Posted November 22, 2011 Author Report Share Posted November 22, 2011 There is a line that goes from distributor and the splits to carb and an open line, but once the open line is plugged it runs a bit better. It seems float seems to high too . I'll try to take a pic if it better helps ..... Quote Link to comment
Phlebmaster Posted November 22, 2011 Report Share Posted November 22, 2011 Pictures are a BIG help....and on this forum are a necessity as you will soon find out. :-) Quote Link to comment
datsunaholic Posted November 22, 2011 Report Share Posted November 22, 2011 An open line is generally a huge vacuum leak, so if it's not hooked up it better be plugged. It's probably meant to go to the vacuum switch and then to the EGR, but I'd have to get my Z20S manual out and be sure. It could go to the carbon canister too, I just can't recall. Z20S engines have a medusa's-head mess of vacuum lines, and they're really twitchy when they aren't connected properly. My near-identical car is in storage 2 counties and 100 miles away so I can't just go look. What I can say is the idle speed and idle mixture screws don't do anything when it's not idling. If it's running on the primary (throttle cracked open) the idle circuit gets "washed out" by the air going through the mains. Quote Link to comment
Nell Posted November 22, 2011 Author Report Share Posted November 22, 2011 <a href="http://s1216.photobucket.com/albums/dd379/aernyll/?action=view¤t=a9e491c6.jpg" target="_blank"><img src="http://i1216.photobucket.com/albums/dd379/aernyll/a9e491c6.jpg" border="0" alt="Photobucket Pictures, Images and Photos" /></a> Quote Link to comment
Nell Posted November 22, 2011 Author Report Share Posted November 22, 2011 Sorry let me try again Picture http://i1216.photobu...ll/a9e491c6.jpg Quote Link to comment
Nell Posted November 22, 2011 Author Report Share Posted November 22, 2011 Another thing I noticed is when choke is close it will sorta run better, open line plugged, then once it opens fully it stalls too Quote Link to comment
Phlebmaster Posted November 22, 2011 Report Share Posted November 22, 2011 Sorry let me try again Picture http://i1216.photobucket.com/albums/dd379/aernyll/a9e491c6.jpg Try using the IMG code Quote Link to comment
Nell Posted November 22, 2011 Author Report Share Posted November 22, 2011 Try using the IMG code The open line is the one I'm holding Quote Link to comment
datzenmike Posted November 22, 2011 Report Share Posted November 22, 2011 Sorry let me try again Picture http://i1216.photobu...ll/a9e491c6.jpg That line probably goes to the thermal vacuum valve mounted to the front of the carb on the intake. The thermal vacuum valve will not allow vacuum to the EGR or the distributor until the motor warms up. The valve is actually a small air bleed that lowers the vacuum signal. When the valve closes the bleed is stopped and full vacuum is passed on. Seal it and it will work just fine. Quote Link to comment
Nell Posted November 22, 2011 Author Report Share Posted November 22, 2011 That line probably goes to the thermal vacuum valve mounted to the front of the carb on the intake. The thermal vacuum valve will not allow vacuum to the EGR or the distributor until the motor warms up. The valve is actually a small air bleed that lowers the vacuum signal. When the valve closes the bleed is stopped and full vacuum is passed on. Seal it and it will work just fine. Where does the end I'm holding go to, the edge is jagged so my guess is that it tore from something, I don't want to seal it if it has a specific purpose Quote Link to comment
datzenmike Posted November 23, 2011 Report Share Posted November 23, 2011 Read my post. It's just an emissions thing. Having the vacuum advance on when the motor is cold actually pollutes slightly more. Nissan designed a thermal valve which prevents vacuum advance until the motor warms up. Plugging that hose will simply eliminate the valve and give vacuum advance at all times. It should look similar to this one. The vacuum advance goes on the bottom. The next one up goes to the EGR valve, the top one to the air filter. These things are easily broken . Quote Link to comment
Nell Posted November 23, 2011 Author Report Share Posted November 23, 2011 Plugged it still no idle , do after hours of inspection I realized the choke wouldn't idle unless the choke was close so then I brought my attention to the automatic choke and there it was . The power wire slipped out of its connector . Fixed that and the it fired right up and the I just adjusted the carburetor, took it for a hour test drive. I think I'm out of the clear Quote Link to comment
Nell Posted November 23, 2011 Author Report Share Posted November 23, 2011 Sorry for spelling errors and wrong word placements, had a few celebration beers Quote Link to comment
datzenmike Posted November 23, 2011 Report Share Posted November 23, 2011 Trust me.... it's easier to understand than some sober posters. Quote Link to comment
Phlebmaster Posted November 24, 2011 Report Share Posted November 24, 2011 Trust me.... it's easier to understand than some sober posters. I nkow wat u mane. :P Nice work Nell!! :D Quote Link to comment
Nell Posted November 25, 2011 Author Report Share Posted November 25, 2011 Thanks for all the help Quote Link to comment
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