Ducer Posted June 20, 2011 Share Posted June 20, 2011 (edited) Hey guys so I bought this 1974 260z and thought that I could deal with carburetors and all that good stuff, but I am stumped. Having owned many 240sx S chassis, and grasping the full understanding of those cars, I'd figure that Z's be a lot more fun and easier somewhat. What I have: 1. 1974 260Z 2. Flat top carbs which I should have researched before buying GOOD: 1. Compression #'s 150 to 180 psi range on all 6 cylinders (CHECK) 2. Fuel goes to bowls, CHECK 3. Sparks (Check) BAD: 1. Will start but wont stay on, and I have to keep the starter going to aid the engine to keep running. So Reving the engine means I turn the KEY harder. Really weird!! Let go of the key to spring to "ON" the car will die. But turn it harder to crank it, the car REVS up. Freaking odd. SO basically the Accelerator is the Ignition switch. 2. Plugs look fouled. Black dry, as fuel is RICH SO THE HAINES, AND ONLINE DOES NOT HAVE VACUUM DETAILS, SO PLEASE LET ME KNOW IN MY PICTURE WTF IS WRONG AND WHAT i NEED TO DO. I LABLED AS MUCH AS POSSIBLE. PLUSE USE THE LABLES ON THE PICTURE AND GIVE ME SOME POINTERS. I DELETED THE EGR STUFF AND ALL THE NON USE STUFF. NOW, BEFORE i THROW THESE FLAT TOPS OFF A BRIDGE AND GET A HOLLY OR SU CARBS, HELP ME AND LETS SEE IF WE CAN MAKE IT WORK. THANK YOU! Edited June 20, 2011 by Ducer Quote Link to comment Share on other sites More sharing options...
Pharaohabq Posted June 20, 2011 Share Posted June 20, 2011 I'm not sure it's the carbs. I'm curious about your starter switch. It sounds like there's a short or something in your switch, under ACC/ON on your car should have power to the coil. Now I'm not so certain about the 260Z, but there's the safety interlock system too. You might need to bypass that, or lock the seatbelt behind the seat when trying to start it. When you're revving the engine with the starter, are you pressing the gas pedal down? You may need to pump it a little while starting. Is there oil in the carbs? I don't see anything wrong on your picture... Cept that hose next to "Fuel to rear carb" is that the smog pump that's not hooked up or AC or what? Quote Link to comment Share on other sites More sharing options...
Ducer Posted June 20, 2011 Author Share Posted June 20, 2011 (edited) I'm not sure it's the carbs. I'm curious about your starter switch. It sounds like there's a short or something in your switch, under ACC/ON on your car should have power to the coil. Now I'm not so certain about the 260Z, but there's the safety interlock system too. You might need to bypass that, or lock the seatbelt behind the seat when trying to start it. When you're revving the engine with the starter, are you pressing the gas pedal down? You may need to pump it a little while starting. Is there oil in the carbs? I don't see anything wrong on your picture... Cept that hose next to "Fuel to rear carb" is that the smog pump that's not hooked up or AC or what? I suspect that the Switch was bad as well. It may not spring back to the ON and that's why. I don't even touch the gas pedal when using the key to rev the engine. I did remove the seat belt unit while cleaning rust and the seat belts are not connected. Hmm, I didn't know that Seat belts had to do anything with starting the car, but if it is a safety feature, Please let me know what to do. I assume 260z's will have what 240z's have and much more, so please show me how to do that bypass on the 240z and I'll make sense of it with my 260z. There is new Dampening oil in the carbs. Filled 2/3 in the cylinder, so that's okay. With regards air pump was taken off as well as A/C. EGR is blocked off, The hose on the left of the "fuel to rear carb" is Water/cooling line, I suspect. Compression is 150psi through 180psi on all cylinders. 1. RICH 2. CARB is definitely off 3. It will start up with starting fluid, but seems to only stay on or continue with the starting helping it. Bad. I should just get 1 holly carb and call it a day. God I need money. Edited June 20, 2011 by Ducer Quote Link to comment Share on other sites More sharing options...
neotech84 Posted June 21, 2011 Share Posted June 21, 2011 I say it's electrical too. Sounds like your ignition, the seat belt or other wiring that is keeping you from starting. There are some good places to start in the FAQ section and xenon's fsm site. Quote Link to comment Share on other sites More sharing options...
beermanpete Posted June 21, 2011 Share Posted June 21, 2011 It sounds like an electrical problem to me as well. The ignition switch has a bypass for the ballast resistor. When in the "crank" position there is an alternate path for voltage to the ignition. The ignition switch could be bad in the "on" position and good in the "crank" positon. Check the voltage at the ballast resistor. One side should be battery voltage (about 12 volts) when the key is on. The other side should be about 9 volts when the key is on and the engine is not runnig (and the points are closed). When the key is in the "crank" position the voltage should be battery voltage (about 9 or 10 volts when crancking) on both sides of the ballast. You could try hot wiring the car. If the ignition switch or a connection is bad somewhere you should be able to make it run by bypassing it with a jumper wire. Quote Link to comment Share on other sites More sharing options...
Ducer Posted June 27, 2011 Author Share Posted June 27, 2011 (edited) Hey guys! Thanks for the help and I went to the Datsun Swap Meet here in Eagle Rock today and bought me a Clifford manifold and a holly carb set up. I installed the holly set up and BAM, it's perfect. Runs great and no issues. Oh, I had the timing sequence off so that was an issue. I think I had it 153642 or in some weird order. now it's back to 15 36 24. But even with the right order, the Flat Tops failed even with rebuilding them and all, so my friend pushed me to buy the new carb set up and Im so thank full. Feels so good getting out of the a deep hole. So it turned out: 1. It was not the ignition switch 2. It was not the safety seat belt system 3. It was not the vacuum. 4. IT was the Flat Tops. So, I didn't want to believe and tried to salvaged these Flat tops, but once you go with a single 4 barrel holly, you'll never go back. SHE's ALIVE! Thank you so much guys. I appreciate it. The Datsun Community is very cool. I've always been a Nissan enthusiast but getting older now and it's time to go back in time a bit. NOW on with the resto. My custom coat hanger linkage works great! Now that it starts and runs, Im pulling the motor and trans and pressure washing it and painting the bay, Deleting the A/C and Heater cores, and anything I don't really want, new dash is much more. Woot. Edited June 27, 2011 by Ducer Quote Link to comment Share on other sites More sharing options...
Tony D Posted June 27, 2011 Share Posted June 27, 2011 So when will you give me the free set of crappy flat tops? Quote Link to comment Share on other sites More sharing options...
Ducer Posted June 28, 2011 Author Share Posted June 28, 2011 So when will you give me the free set of crappy flat tops? I would like a few bucks for it to compensate for the expensive carb set up I just bought. Let me know who much you want to pay and you can pick it up. Thanks. Quote Link to comment Share on other sites More sharing options...
twofouroh Posted July 6, 2011 Share Posted July 6, 2011 Tony, if you werent serious, I am also looking for a pair for parts for my flat top setup. Sorry Duce, I can't pay much for them since they don't run at all, but I would like to have a parts set for mine. You can check out my video to hear mine run, they are just fine once you get all the bugs out! They are actually the original carbs my 74 came with - PO took em off and put them in a box . . . kinda rusty and some broken parts, but they run way better than any of my round tops do. Quote Link to comment Share on other sites More sharing options...
Ducer Posted July 6, 2011 Author Share Posted July 6, 2011 (edited) Tony, if you werent serious, I am also looking for a pair for parts for my flat top setup. Sorry Duce, I can't pay much for them since they don't run at all, but I would like to have a parts set for mine. You can check out my video to hear mine run, they are just fine once you get all the bugs out! They are actually the original carbs my 74 came with - PO took em off and put them in a box . . . kinda rusty and some broken parts, but they run way better than any of my round tops do. I actually sold them already earlier today. Got some good gas money for them, so I am happy. I would never go back to Hitachis or the dual SU's. The Holley set up is much more superior and easier to play with and looks cleaner without all that balance tube and smog stuff. Finding parts is much easier and WTF, Hitachi? They make electronics and home appliances, Holley makes Carbs. More power and reliability with my Holley carb. Love it. Edited July 6, 2011 by Ducer Quote Link to comment Share on other sites More sharing options...
Tony D Posted July 6, 2011 Share Posted July 6, 2011 Er, yeah... Quote Link to comment Share on other sites More sharing options...
neotech84 Posted July 6, 2011 Share Posted July 6, 2011 Er, yeah... Great restraint Tony...... give your self a pat on the back!! Well it's great to hear all is well with the single carb. Enjoy the Z! Quote Link to comment Share on other sites More sharing options...
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