240z running rough

[rosaaen89]

i have that linkage connected back at the moment. does that linkage only move from the choke cables and that pulls the nozzles down? or does it move with the throttle linkage as well. when i move them by hand they both move up and down but if i extend the lever to far they stick but maybe they do at that point when the lever is overextended ?

[Mark Maras]

 The main function of the choke cables is to pull the nozzles down, richening the mixture but the linkage also opens the butterflies a bit. That allows more air into the mixture and raises the idle RPMs. The nozzles shouldn't stick. Try lubing them first if that doesn't work check the nozzle linkage alignment. You may have to twist the linkage (circled in red, above) to be sure the mating surfaces on each end are parallel to their attachment points.

[rosaaen89]

when i took off the top of the float bowl i noticed one of the jets that is suppose to press up against the metal bracket on the float didn’t have any tension . so i ordered new ones with new float bowl gaskets since there wasn’t any of those on there either 

[rosaaen89]

i finished putting everything back together and installed new throttle return springs and the float bowl to carb hoses as well as the jets in the float bowl and it runs 10x’s better then it did. doesn’t sputter like it was and runs pretty good. it does seem like it’s running rich now but it’s night and day difference then it was. 

[rosaaen89]

[Captain Obvious]

Glad you're doing better.

If you're running rich now, it might be because of that messed up needle (at least at idle). For the cost of a pair, I'd replace them. That one has clearly seen better days.

[Mark Maras]

Sounds pretty good. Did you check the float bowl fuel levels and how many turns down are the nozzles?

[rosaaen89]

the nozzles i set both at 2.5 turns. i’m guessing 1 turn = 360 degrees counter clockwise correct ?  i didn’t check the float bowls yet to see where the fuel is currently at. the throttle return springs that were on there as well were different. but yes i think i should do the needles at least the one. is it necessary to have the choke cables hooked up ? sorry for all the questions but your help has vastly helped me with this 

[Mark Maras]

 Correct, 1 turn = 360`. I'm not sure what you want to do to one needle. The piston drop and lift test seems to have confirmed the needles aren't scrubbing the nozzle ports. Just looked again. I think I see what you mean. The top (base) of the needle looks like someone wrestled it out of the piston with new sharp pliers. It also appears to be bent or is that just my eyes? I don't believe there's a good reason to hook up the choke cables if you don't need the choke but that could be a too rich symptom. The piece of flat bar linkage that pulls the nozzles down needs to be installed. 

[rosaaen89]

it possibly is bent i’m probably gonna order new ones just to be safe. i think i fixed one issue sort of with the way it was running real rough. but the other one continues , so i primed it got it running good . turn the car off and the fuel that sits in the fuel filter slowly goes back down and once there’s none in the fuel filter it won’t start unless i prime it that way i was doing it. i hooked a hose straight from the fuel pump to a separate source of fuel and it still don’t start that way. could the pump itself be bad? the previous owner replaced it thinking that was the issue for it running rough right before i bought it  less than a month ago. maybe installed it wrong if even possible. or could there be a leak in the line letting air in when it’s sitting and not running ?? i’m lost

[rosaaen89]

well i looked underneath the back by the tank and one line going from the tank to the hardline that runs to the engine bay is loose, old , hard and brittle. i’m going to replace that and see if maybe that’s why it kept doing that 

[rosaaen89]

both float bowls were equally filled. i changed out the rubber fuel line going from the tank to the hard lines with the correct size as well as the rubber return line in the engine bay. it’s still having the issue where it’ll run and drive and soon as i park after a few hours all the fuel will drain back out of the filter. i’m thinking maybe the new mechanical fuel pump is bad already?? i took it off and the gasket going between the fuel pump insulator/spacer and engine was all torn up and there was some oil coming in the fuel pump itself. could that be the issue ?