Strange fuel issues

[weebyjosh0223]

So recently I’ve put some new injectors in my 93 300zx NA, but have come across a weird situation. I installed all the injectors correctly. I even took the out again once I thought I tore an o-ring because it locked up, but everything was okay. After being frustrated I called out my old man and he told me to swap the fuel supply and return lines on top of the plenum. I did this and the car fired right up. When routed the factory way, it would instantly hydrolock cylinders 1-3-5. The car is able to run, I’ll be it poorly, in this reverse fuel line set up. Even after the key is turned off and removed it continues to run. Does anyone know why when my fuel lines are routed correctly, it locks up? Thanks in advance. Here are some pictures to get a better understanding.

[macgiver]

Hydro-lock is flooding past one or more injectors (3 ? ) , either leaking THROUGH an injector , or your case likely leaking past damaged intake o-ring (lower/smaller o-ring). Ya really gotta STOP and figure out fast what's happening , for cranking under hydro-lock CAN damage bearings (rod ) especially IF engine is stopped days-weeks w/oil drained down & poor oil film protection = some poss. permanent damage
ALL 3 in one bank points to probable shifting during install and not seating good at all.

Doing f/inj. ....... Do this - pull plug from that cyl , keep piston high up (less fuel buildup) , after proper inj's installed go cover spark plug hole w/rags and with IGN & INJ FUSE OUT ! crank engine 2-3 seconds to blow out gas in cyl ....Always watch gasoline isn't dripping onto starter AND wait couple min and crank again for a better emptying of gas in cyl , then I let car alone for residual gas to evaporate (car should be clear of buildings here too!) . NOW I finish job by test crank again then again WITH plug installed THEN put back Inj FUSE only to try for SMOOTH cranking motor , LASTLY put the IGN FUSE back in for running test ......OBSERVE ALL ....OK ?? good

Basically , most don't realize just how MUCH gas may enter cylinders doing even a single f/inj R&R !!

[weebyjosh0223]

Hydro-lock is flooding past one or more injectors (3 ? ) , either leaking THROUGH an injector , or your case likely leaking past damaged intake o-ring (lower/smaller o-ring). Ya really gotta STOP and figure out fast what's happening , for cranking under hydro-lock CAN damage bearings (rod ) especially IF engine is stopped days-weeks w/oil drained down & poor oil film protection = some poss. permanent damage
ALL 3 in one bank points to probable shifting during install and not seating good at all.

Doing f/inj. ....... Do this - pull plug from that cyl , keep piston high up (less fuel buildup) , after proper inj's installed go cover spark plug hole w/rags and with IGN & INJ FUSE OUT ! crank engine 2-3 seconds to blow out gas in cyl ....Always watch gasoline isn't dripping onto starter AND wait couple min and crank again for a better emptying of gas in cyl , then I let car alone for residual gas to evaporate (car should be clear of buildings here too!) . NOW I finish job by test crank again then again WITH plug installed THEN put back Inj FUSE only to try for SMOOTH cranking motor , LASTLY put the IGN FUSE back in for running test ......OBSERVE ALL ....OK ?? good

Basically , most don't realize just how MUCH gas may enter cylinders doing even a single f/inj R&R !!

I’m not cranking with it locked, I know better than that haha. What I’m saying is the o-rings on the injectors are good and they’re brand new so I don’t find it likely for that to happen. From the fuel filter to the regulator and return lines, they have been swapped just to see what would happen. I’ve spun it over without plugs in to eject fuel. I’m mainly concerned about why it’s not fuel dumping the way it’s currently hooked up vs why it is when the lines are routed correctly.

[macgiver]

Yes , it certainly still seems "all-around " baffling . And the reversal of the lines , wow how did you figure that ? But I see trying that just pryed open Pandora's box a little more . But for now , to move forward I believe the connecting it 'proper' and pursuing that way is quickest solution , and amazing your diagnostic reversal experiment gave you SOME clues ? and NO serious problem , I applaud . BUT be careful with those kinds of experimentations - could go South reeeeal quick , ya know .

Sometimes we do have to go out on a limb , well you do sound VERY capable , I'm stumped but do come back , report any progress ya . Good luck weebyjosh

[weebyjosh0223]

Yes , it certainly still seems "all-around " baffling . And the reversal of the lines , wow how did you figure that ? But I see trying that just pryed open Pandora's box a little more . But for now , to move forward I believe the connecting it 'proper' and pursuing that way is quickest solution , and amazing your diagnostic reversal experiment gave you SOME clues ? and NO serious problem , I applaud . BUT be careful with those kinds of experimentations - could go South reeeeal quick , ya know .

Sometimes we do have to go out on a limb , well you do sound VERY capable , I'm stumped but do come back , report any progress ya . Good luck weebyjosh

I’ll probably pull the fuel rail and replace all the seals it sits on. Thanks for the encouragement. I’ll definitely look into everything to end for fuel. And replace anything I can. I’ll come back with updates as soon as I get results

[macgiver]

Try not to use the little green emoticon.................................I thought I owned it (LOL I USE TOOOOO much! ) ?
Just kidding , no one really spells ,writes , verbalizes , and punctuates like me , so sad..........cant' help it tho
Enlish / LIt was my worst subject .......................