caszboy

YOU ARE NOT ALONE. i am having the same problem on my 1974 260z. its carburated and i have a electric fuel pump installed. I just got done.. -cleaning out the entire tank -replacing fuel lines/vent hoses -eliminated the vent tank to simplify things (plus all the hoses where kinked anyways) -replaced all fuel filters. The problem has been getting progressively worse and worse. I thought it was temperature related (still might be) but today the temp dropped like 15-20 degrees here and i still have the problem. Also, my fuel pump goes form loud to quite and back and forth and i cant figure it out. Im going to go pick up a fuel pressure gauge today or tomorrow for carbed cars and see what it is at the rail. Im going to be following your thread a lot i think ;p

OK, here is the deal. As some have been following i will update the scenario. As im driving around town. Every 10-30 minutes of driving the car will stall. Usually either at stop or right after accelerating from a stop. If i let it sit for about a minute or so, it will fire right up as if nothing has happened. It is easy to start when cold and runs great except for the stalling. I thought the car was starving from fuel so i droped the gas tank and the conditions of the tank were not bad at all. so i got a tank cleaner and poured it in and sloshed it around and now the inside of the tank is VERY clean. I also ditched the metal fuel filter before the electric pump and installed a clear one from pepboys. the filter is clear with some minor particles from the cleaner still working but nothing even close to clogging it up. I noticed last night that after the car stalled in a parking lot, The fuel pump was changing sounds. From Kind of loud to quite and back and forth. I pulled a spark plug today and this is what i found... Also i changed the dizzy to the 280zx E12-80 dizzy about 2 months ago. the car ran great for about a month after swapping. here is a picture. the dizzy has two vacuum tubes so i just plugged one and used the other. here are the carbs that i have, the webers. so after all that, here is the $1,000,000.00 dollar questions... - Do yall think it is the fuel pump? ( i have electric and the mechanical one is disconnected) - Do yall think it is the dizzy or the E12-80?...is it OK to just plug one of the vacuum lines and use the other one like i did? - Do yall think it is the weber carbs? - Does it look like it is running rich, lean or correct? I NEED HELP!!!!!!

Well, I just called a place around here and they gave me an estimate of $275-350. That’s basically a new fuel cell with all the goodies. So I’m not getting it professionally done. -So- I’m going to run up to pepboys/advance auto and see what I can come up with. I think I’m going to go the POR-15 route if I can find it locally. Otherwise just scrub the heck out of it with marine clean. I’m going to blow the pump line out with air then put something the same size down in the tube just to prevent anything from getting up there while I’m sloshing stuff around. Or I might make the drain plug the new line to the fuel pump. This would make the line bigger and less likely to clog. I would rather it clog the filter since that is easily replaced but this method would also expose the fuel line more as well. Hmmmm…… While I’m at it, I might and try to simplify the venting and eliminate the vent box. It just seems like such a waste of engineering. Plus, some of the hoses are kinked and have prevented me from filling the gas tank all the way anyways. I will have to do some more research with that. And one last thing...What do the metal spring and piece of metal belong to????? I will keep you guys updated. Thanks for the input I don’t know what I would do without Zcar.com and Hybridz.org!

ok, here is an update on my tank. i removed the tank and this is what i have found... this is the gas that came out of the bottom. And yes that seed came out of the gas tank! where did the spring and pice of whatever come from? im guessing my gas float thing (cant remember what its called as this moment) do yall still think i should try and clean it myself? or get it professionally done? i couldn't see on the other side of the slosh wall to get a photo of that.

ok, on Tuesday im going to drop the tank and see if i can get some crud out of there. i just replaced the filter and it helped for about two days. It died twice today at lights. i had to sit there while traffic is flying by at 45mph hoping not to get rear ended. waited for about 1 minute for the fuel pump got some fuel back in the lines and she fired right up. i bought extra filters while i was at Autozone. im going to try the Marine Clean thing and see what happens. I will keep you guys posted on how well it works.

well, here is a update... i changed the filter before the pump and let the old one dry. when i tapped the old filter on a piece of wood, rust fell out. I'm figuring out how to afford the tank treatment now. i was told to take it to a radiator shop. so for now, i'm going to let it sit. i have ordered a new muffler also. So i'm going to do everything at once including taking off the rear bumper! every time i walk by it my pants rub on it and i get black marks from the old rubber bumpers. thanks for the help everyone! i just have to see where this takes me

Im going to rework the fuel system with all new stuff and boil my tank. im just trying to limp along for now. im a poor, broke college student i was searching and found this thread by Tekira. Its using the drain plug as a fuel out to the pump. I hope you dont mind me quoting your thread... anybody else try this? it would open up the line considerably and simplify it from the tank to pump. any thoughts?

My Haynes manual states that... "the supplementary electric fuel pump was fitted to the 260z. At engine speeds above 400 rev/min (cranking) both the electric and mechanical pumps are in operation." the mechanical fuel pump is not hooked up at all. should i hook it back up? or is the electric fuel pump enough? i have the downdraft duel webers. what should the fuel PSI be ideally at the carbs?

oh, im just letting it dry to see if rust falls out of it.

is the electric fuel pump that i have stock? or from Nissan?

OH, i forgot to mention. the problem is recent but slowly becoming more frequent. so do you think there are any other filters/screens that i need to change, clean while I'm at it?

When i drive around town, the car will stall when I'm cruising at a constant speed or after hard acceleration. If i just wait for 30-45 sec it will start back up like nothing happened. The previous owner disconnected the mechanical fuel pump and installed a electric fuel pump with a range of 2.5-4 psi. I'm currently waiting for the filter to dry out to see if there is rust build-up in there. the previous owner told me that he was driving on a road trip once and the car stalled. he changed the filter (pictured) and no problems since. Is there a screen or anything in the pump to clean? I'm going to replace the filter and reinstall both and then test the fuel pressure. is there anything else that could get clogged? any filters in the tank? or anything? i know i need to get the tank boiled but I'm poor! ;p so that will be in a month or two.

in that case, no idea. someone on here might have it but if not... just use the process of elimination with a voltmeter. 1. Turn the car onto the on position. test the wires. if you get a 12+v, then you just found the IGN (+) and a ground. if you get a -12+v, then you have found them just reversed. mark them and move on. 2. Next, turn the lights on and test the remaining. Using the same method as step 1. when you get the voltage, mark it. now you have the LTE (+) and another ground. 3. if you are using the clock plug, it should not have the other two wires for signal wires so you should be all set. hope this helps

wrote this up for everyone on zcar.com not to long ago... enjoy! This is on a early 1974 260z OK, i ordered new autometer oil pressure/water temp electrical gauges and i am very pleased! Just to kind of centralize information... The oil sender is 1/8" - 28 BSP The water temp sender is M16 x 1.5 On a 4/74 (and i guess close models?) the gauges in the triple pod can be removed by removing the vent/heater control housing. you do not have to take out your whole dash! its kind of a tight fit but I'm used to that from installing car stereos. Also, here is a drawing of the stock wiring if you want to wire your gauges in. i ran new sender wires b/c my stock gauge failed and didn't feel like hunting down the problem and then some pics of the car thus far with the gauges installed. hope this helps someone sometime in the future

damn blueovalz, you have one hell of an eye for this stuff . the turn signals just dont match the car. it looks like it is suppose to have the signals on the ugly bolt spots, i just dont have any holes or a way to mount them. so srgunz, you think the wrong air dam is on it now? that would explain a lot about the big grill and bolts showing. maybe i will change it when time to paint....which is a long ways away another question... im looking to make a daily driver, non-show car, but looking nice ride out of this. im not totally new to bodywork but not as experienced as most. see anything wrong with just using bondo around the sunroof? after taking it out of coarse...and yes the previous owner put tape on it

I was just looking at the front of my z the other day and something looks weird. i have seen other pictures of Z's with the front air dam and mine just seems like its missing something? maybe the front "thin" chrome bumper? the two bolts on each side showing is really bothering me what do you guys think?

ok, well i just ordered the: Equus Oil Pressure & Electronic Temperature Metric Adapter Kit. It came out to be 12.24 after shipping. not to bad for 5 fittings since the local Race Shop wanted to charge me $9.90 just for the oil pressure sender adapter. now i just have to wait the darn shipping time. i will let you guys know. thanks for the help

ohh, yeah sorry. im used to zcar.com from my sig ;p but its a early 1974 260z. 28 British thread? man i thought there was just standard and metric ;p what about the water temp sender?

OK, i have a set of autometer gauges and mounted them and looking good but the thread pattern for the stock ones i guess is metric? while the autometer gauge is standard. i am going to a plumbing shop monday to get adapters but i NEED to know the thread size for the stock oil pressure and water temperature senders. thanks in advance