Bad fuel pump? CODE 21, 34, 32

[BrianZ32]

Back here again

So here we go. Hoping some of you guys can help a fellow out. These past couple weeks, 93 Z32 2+2 has been starting up real funky. I'd start it up and it would bog as if its about to turn off but didnt, atleast not a couple weeks ago. Also, it has been having a rough idle, mid 1500 rpms and it takes a while to regain itself, but the second id start driving,idle would go back up again. So a couple days ago, my Z decided to not start up completely, crank, crank, crank, no start. All lights go on, dash, headlights, even my alarm dings, but just wouldn't start. Had to go to work still so ended up taking my girlfriends car, came back, and it started easily... WHAT
Anyway, this morning, it did the same thing. All lights light up, alarms dings, crank but no start. Idk if this is coincidence but my fuel gauge has been acting up. Stays on E until about 10 mins of driving and it goes back to normal. So back to this morning, i did some research and here is what i have done so far. I have checked the CAS, works fine. Checked PTU harnesses and cleaned them out because they were corroded but still didnt seem to work. Finally i checked my fuel filter, took off the hose (after about 15 mins of struggling) turned the key to ON but no fuel. Im convinced that it is probably the fuel pump. I recall, when it was working fine, anytime i would turn the key, i can hear the fuel pump behind me for a couple seconds and now, i dont hear it either when i turn the key. I am a rookie when it comes to doing mechanical stuff but i can work my way around a thing or two. I enjoy working on my own car and so i am ready to replace the fuel pump, however, it is not that cheap. Looking at about $200 from local autozone. I just want to get your guys' opinion before i purchase the part because if i buy the part and car will still not start, i will be frustrated as i am a college student balling on a budget lol. I love my car to death but she has not be treating my right lately. Let me know what you think as she is my daily and have had to miss work a couple times. Thankfully, it is almost the end of the week so i can work on it, just have to find a ride to work tomorrow. Idk if im missing out on any info but any questions, please ask as i will be checking on this for the rest of the day.

Edit: One thing i forgot to add, i tested coil packs on all 6 and got a range lowest 2.6 ohms highest 4.4 ohms
I was told that as long as they average about the same, it shouldnt be the issue. I hear and read alot about FP relay but not exactly sure how to test to see if that could be the issue.

[brian300zx]

When fp relays fail it’s usally when it’s hot outside or that has been my experience. Then once it cools down starts just fine. As far as testing it I’m not sure but they shouldn’t be too expensive at an autozone or something like that. If you see it doesn’t solve your problem just return it

[BrianZ32]

When fp relays fail it’s usally when it’s hot outside or that has been my experience. Then once it cools down starts just fine. As far as testing it I’m not sure but they shouldn’t be too expensive at an autozone or something like that. If you see it doesn’t solve your problem just return it

I can't exactly return a fuel pump once i install it which is why its one of those frustrating fixes. I stay in SoCal so the heat here is immense. But at this point, the car wont start at all, this is day 3 of no start

[brian300zx]

I meant the fuel pump relay. Yes I’m in SoCal as well. But if you don’t hear the fuel pump prime it’s either the relay or the pump itself which is why I suggested the relay because that’s easy to replace and you can return it if it’s not the problem

[macgiver]

mac here, I had virtually same symptons as you with my (same year) 93 J30 2 months ago - it WAS the often ignored and left for last - a relay , The fuel pump relay , which in my case - and maybe yours - was the hardest to get to. Because electrical/electronics is my forte , I troubleshot , tested , measured everything from fuel pump ,fuel pump control unit , dropping resistor, even wire connections to "other end" connections ,finally sprayed De-oxit Gold on connectors(very sparingly) pushed on/off a few times for best el. contact (all this fairly easy)- still intermittant . So then I go for the (24 y'old) relay - remove drvr's underdash,cardboard ,solid panel ,sidekick,trans.ctrl unit. p.s. ctrl.unit , another ctrl. box and in inside the behind the door hinge fenderwall , one of two relays (other was "rear tailight relay) - I did a "post mortem " autopsy w/dremel wheel and the power contacts were showing, and obviously extremely degraded - yet THE COIL & relay PINS were good enough to fool me when i always heard it clicking with "key on" . Voltage will not show at the fuel pump control relay and I could have zeroed in quicker (quick & dirty) but being the "sparkey" that I am - now I know from all those checks and the De-oxit that my fuel supply is electrically sort of "bullet-proof" now.Glen 10/29/17

[Ace2cool]

^ solid info here. If you have the means to check voltages at the pump, do that first. But if your gauge is messing up as well, I'd say you're looking at either wiring to the pump or the pump itself.

[BrianZ32]

^ solid info here. If you have the means to check voltages at the pump, do that first. But if your gauge is messing up as well, I'd say you're looking at either wiring to the pump or the pump itself.

UPDATE: It ended up being the fuel pump, replaced it and it immediately fired up. However, i couldnt find the lock ring seal and i can def hear some air or some type of pressure coming from the trunk. Already ordered another and still have to fix my fuel gauge. It is stuck on F, i have a feeling its that floater thingy, i remember messing with it when i replaced the pump.

[DCaff300ZX]

Also be sure your fuel cap is holding pressure as the fuel system is pressurized, and that sound could easily be the cap leaking pressure.