Alex240z

I bought new ones so they don’t cripple. Only issue it feels like is the fuel isn’t going into the carb. I can feel the fuel inside of the hose but it seems like no pressure is pushing it up. I did the straw method to test to see how much fuel is in and I saw the fuel spill off to the sides of the float chamber because my gasket is pretty much gone. Could this be preventing enough pressure to build up in the chamber to push the fuel into the carb? Do I have to cover the nozzle that connects the chamber to the air filter? I checked the jet and blew through it and the air flows through it just fine. The piston goes up nicely and falls down with a click. The floats are adjusted properly but one of the pin inside the front carb didn’t go back to the resting position but I took it apart and fixed it. Each chamber has 20mm of fuel in them. Did the drop test and it was fine. I’m just lost at what is the problem.

I adjusted it as you said but I’m still not getting any gas into the chamber. Pressure builds up and everything until it goes to line from the float chamber into the carb. Am I not having enough pressure in my fuel lines? I don’t think I have a vacuum leak. Only thing I didn’t plug up was the fuel tank evap into my cylinder but I doubt that’s the cause of anything. I put on another mechanical fuel pump but found out that one didn’t work well compared to the one I had. Pressure builds pretty quickly and I’ve taken apart the carb to inspect the needle and everything seemed fine. Not quite sure what’s wrong with the carb.

I think your assumption of the floats being out of tune was correct. Seeing that the fuel only filled a small portion of the chamber. I’ll go about adjusting it and see what I get. The more and more I open this carburetor the more I feel the need to rebuild it. I’ll let you know how it goes

Here is the float on the rear carburetor and also the float chamber. Also forgot to mention that these are 4 screw SU. I did use the gas can before and that’s when I had it running. When I hooked it up to the tank didn’t run so well.

Sweet thanks for the feedback I'll check that out. If the carb is not getting enough fuel what would I have to do to adjust it? I think I had a smooth brain moment because I just assumed the SU carbs had damper oil and when I checked it this morning after just remembering there was none. Not sure what effects that has but my carbs would love to just spit out fuel.

Hello, I recently got a Datsun and I’ve been trying to tune the carbs so I can finally drive it. Unfortunately the carbs have been extremely weird. I’ve been following this page https://zcarguide.com/tuning-adjusting-datsun-240z-su-carburetors/ on how to tune the carbs. After I follow all the steps to step 10 where it says “start engine” the car shoots to 2000rpm then slowly dies. I’ve checked for vacuum leaks on the balance tube, distributor, and gasket but I’ve closed everything. I don’t know if this has anything to do with this but when I use my choke I’m at 2000-2500rpm but it does keep an idle. Now quite sure what I’m missing. I’ve checked out my Haynes manual but the way they do it is different so not sure which one to exact follow. Any feedback would be great thanks.

View Advert Signal switch and Wiper switch needed Need a wiper switch #25160-E4602 and signal switch #25540-E4600. Thanks Advertiser Alexg280z Date 03/04/2021 Price Category Parts Wanted Year 1971 Model 240z  

You can’t be serious. Fml. The harness I got is from a 4/71 too so that’s beautiful. Is there much difference from a E4600 to a E4602?

Hello everyone, More Datsun issues that I can't solve. So my car didn't come with a wiper switch or a turn signal switch. In a search for one online I can not for the life of me find one that fits the wires that I have. Either I'm missing something or I'm stupid. I've looked on http://datsunforum.com/datsun-240z-sport-1971-fsm-supplement/ for my year car 6/1971. So far the only things that match are the plugs the rest really don't. Here are some photos for reference.

Hello back again unfortunately, another issue. So while trying to stop all vacuum leaks on my engine, I took the balance tube of because the engine was I believe a 72-73 so it had the egr tubbing in it. I ended up using a balance tube from a 71 because it was simpler and less stuff to close up. One issue is that the linkages are messed up. I got it to be able so that when the linkage is at rest the butterfly valves shut. Only issue is the rod from the firewall to the crank bell is too short. Did the datsun’s have a different length rod or did I mess something up? If worse comes to worse I’ll just cut it and weld a piece to make it longer. I couldn’t find anything on it. Thanks, alexander

After a quick search of ballast resistor online I see the problem. I don’t have one.

I forgot to mention that I bought an aftermarket switch from Zcardepot but I’ll give it a try. Thanks again.

Interesting. I’ll check it out in the morning. Any idea on the high reeving?

Hello everyone, I have a 1971 Datsun 240z I’ve had for a while. Unfortunately for me when I bought it the head gasket was blown and rusted the cylinder wall so the engine was seized but I was lucky enough to obtain an engine off a running 1972 240z. My 1971 didn’t come with a harness so I also got one from the same model and production month as mine 1971/6 so it fit nicely In my car. Another unfortunately is my datsun is idling weird. I wouldn’t even consider it to be called “idling.” The mechanical pump is taking in fuel, the ignition coil and distributor is working because I’m getting spark, the engine cranks over and starts when I put the key all the way and hold it on start in the ignition switch. However when I let the ignition switch move to the on position the engine dies. Another weird thing is that when it’s on start the engine reeves to the moon and back. It appears to me that it’s an electrical issue but I’ve already check the harness throughly so I’m not quite sure what’s the issue. The only issue I can really think of is maybe a vacuum or air leak but not quite sure what it could be. None of the connectors or fuse box is running hot so no fires thankfully. Some other stuff that were weird that comes to mine are voltage regulator that I bought has six wires in its plugs but the connector plug only has 5 oil pressure switch isn’t connected dont have a choke cable The harness I bought didn’t come with fuseable links for the starter and alternator. They just soldered some high guage wire instead. I don’t have any photos at the moment because it’s late where I live so when I get the chance I’ll update this thread with some photos so it’s easier to explain. thanks, alexander

thanks for the calcification!

Sweet. I'll try my best to get the right harness. I'm a bit confused on the part numbers. Please bear with me. The source you gave me says for example the dashboard harness is 24012-E8303. I see however that there are some harnesses online that are like 24012-8323. Are they the same parts? Thanks.

Thanks! Just what I was looking for. Do you know if I can use a different year harness? Thanks.

Hello, I own a 1971 Datsun 240z stamped 6/71. One issues Im having with the car is that the entire electrical system is gone and practically all the relays. I have been looking for the same year electrical harnesses (because I'm quite lazy to rebuild the entire electrical system or use some aftermarket harness) but I've only really seen 1972 and wasn't sure if something from another year would fit into mine. If someone has the part numbers for engine, dashboard, and interior harness that would fit into my car that would be great. Any advice and information would be great. If anyone has a complete harness for the same year car that they are willing to sell that would be great too! Much appreciated!

I haven’t been able to check out the voltage readings for the pump and relays yet but Ill definitely try tomorrow if the weather clears up. One question I have is actually about my ignition. My key stays on the “on” position and the car doesn’t run or anything but starts cranking on the “start” position. However it won’t move towards off or lock position. Not quite sure if this has anything to do with this but I’ve ordered a new one to replace it.

Just to clarify would that be 1. Or 2.?

Also, I believe the wires might have shorted. It rained tho day and I saw that the sun roof was leaking right onto the wire connection to the fuel pump. So maybe it’s that. Other than that I’m not quite sure on what’s the issue.

The car is a 4/78 btw

Yeah that relay under the drivers side dash doesn’t exist for me. I tried looking for it under there but it’s just not nor is there the two wires supposed to connect to it. I checked the old pump and connected it to a 12V battery and it worked fine and blew all the oil out of it. But when I installed it back into the car and tried starting it I got nothing. I checked all four fuses and I got electrical signals from them and from the relays and fuses in the engine bay. My theory is that the wire got cut somewhere along the passenger side so my priority is the check the connection under the passenger seat with a dmm and see what’s going on. When I get the chance I’ll let you guys know the exact year. Thanks.

Here are a photo of the relays. I’m not sure if they look good.

I couldn’t measure the Exact voltage to the fuel pump because I do not have a tool that can do it although I should go and get one. I have a small sensor that detects whether there is power in a wire. I put that next to the wire that goes to the fuel pump and it didn’t go off. This is while the engine is cranking. I opened the line right after the fuel filter and while I try to start the car no fuel is coming out of it. I had this car for about a month now. It was last registered in 1990 and from what the guy told me who I bought it off it didn’t run for at least two years. I checked the links and they were good. I’ll try your method and let you know what I get. Thanks.