nefiwashere

Would it be good time to get a fuel rail from zcardepot? Or Just replace the FPR if it is bad What i noticed while driving is lack of acceleration power. In neutral car would seemed to rev up fine. When driving I would pretty much floor it and it would gradually accelerate. After a few minutes car then started to accelerate normal. Would that being something with the AFM? Or also clogged in the fuel line? 1978 280Z EL Paso TX

Ok I’ll move it to the return line. If there is hardly any pressure on the return. There would restriction somewhere on the fuel rail correct? Clogged injectors? 1978 280Z EL Paso TX

Have the fuel pressure gauge after fuel filter. If I move it to the return right below I should still get fuel pressure? Not sure of the size of the T thing in fuel pressure tester. It’s the OEM brand set from Autozone. 1978 280Z EL Paso TX

Could it have anything to do with not having the fuel damper bypass? Any way to bring it down if it continues to stay high? 1978 280Z EL Paso TX

Progress update I did drop the tank. Nothing much to tell on that. Did dump some black stuff out with last remain gas. Replaced hoses with fuel ones from the tank to pump and return. blew air in fuel return from engine compartment with hose disconnected at tank. Air passes through with no issues. I did test by removing the fuel return in the engine compartment gas does come out fine. Fuel pressure was at 40psi and voltage on fuel pump was at 11.4 Reconnected everything and letting car run. Fuel pressure was at 50psi. After a letting run it seem to settle around 45. Rev the engine and it bounces up to 50. Voltage at pump is at 13.6 Need to take her out for a drive and see how she does. 1978 280Z EL Paso TX

Need some clarification on which is the fuel out and fuel return. The pics I find it’s very hard to tell what hose is what. Also my hose location is on the passenger side other pics show it in the middle. Found a decent pic. So top is the fuel out by the look of it.

ill get them changed out, Going to be lowering the tank this weekend to look inside and make sure there is nothing getting stuck or if there is some holes in the pickup line. Never had this issue before with the tank but just want to look. also i want to remove the bumper shocks either way. ? Will it cause any issue if i use an air compressor to blow air into the Flow out and return line on the outside of the tank? want to see if there is something stuck in there. according to mechanic that cleaned out the tank said there should not be ??

Should those 2 hoses be getting pressure at the tank? ill change them out to proper ones either way. In the engine compartment it still has old hoses, not original ones but there not the same as above As far as fuel pressure it has been recently at 40psi when I been doing the current test with the weird flow. Before it did seem that fuel pump was shutting off cause fuel pressure would drop and filter would be empty. So maybe the oil sensor is bad as well. But will address that later once I can get to the bottom of the fuel issue. 1978 280Z EL Paso TX

disconnect the return at the tank? also just to clarify the return is the bottom hose on the tank? thats the way it is connected now,

i have a 1978

I did as you suggested and turning they key to the on position the fuel pump is working but it looks like its not getting gas. I have a clear fuel filter on the outlet of the pump and its barley pushing any gas into it. it get some pulses of gas but its not very much and sometimes it goes a good while with no gas pulsing in. is that normal or should there be a constant flow of gas ? i have put at least 10gal of gas so i know there is gas in the tank. sometimes during when it does pull gas from the tank i here some burping in the tank. when i turn the car off i also here some burping. Meter stayed around 11.45 volts some extra info there is a dent in my tank on the passenger side. i know the outlets are also on that side. Inside the tank how do those outlets look? are they flush to the inside of the tank or are the tubes inside as well? had the car for years and never had an issue with the tank cause of the dent. car also had the tank removed and cleaned out cause of bad gas. Pic of dent attached

I can give that a try, but it is a new OEM fuel pump. After some reading on this site I noticed that my fuel damper is bypassed. Didn’t think anything of it cause I thought it was a small filter. Having it bypassed cause any of my related issues? Sent from my iPhone using Classic Zcar Club mobile

Also, thanks everyone for all the help so far. Sent from my iPhone using Classic Zcar Club mobile

I see. To test it do I just disconnect both wires? Sent from my iPhone using Classic Zcar Club mobile

I get .059 on the meter. so my relay is working as it should. If thats the case what else can be causing my fuel pump to turn off? seem that after it runs for a bit it stops pumping, I dont hear it whining.

Pic of how I wire up the relay. Grounded both arms move. No ground only 1 moves. I poke at the solder points and the wires but nothing changes. Still get no continuity on grounded. Sent from my iPhone using Classic Zcar Club mobile

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so i did the retest on pins 95-96 with Ground, it did fail again but it also did not. what i noticed when touching the pins i herd it click and i was able to get continuity. I than disconnected the power and connected it back. first initial click as usual and tested it again, No continuity. Moved the connectors around a bit and than another click. tested it again and i was able to get continuity. Is this normal?

Not sure either. I’ll retest it. Sent from my iPhone using Classic Zcar Club mobile

So my excel spreadsheet matches each box when testing. I used 2 different meters to test with to make sure I was getting same results. on the resistance test ware i was getting (meter1) 1.0 / (meter2) 0.2 and 1.1 / 0.4 normal to get i difference like that? The one that says fail. I got nothing no continuity at all. as for the weird part. when i replaced with new OEM fuel pump and let it idle for a bit than drove it around with no issues. couple days later i started her up and drove it around but it started to stutter after about 1.5 miles of driving. I than looked at the clear fuel filter and it was almost empty with 20psi fuel pressure, car would run but struggling . after letting car sit for about 10 minutes i tried starting the car up and it cranked up fine. clear fuel filter started filling up with gas with 48psi fuel pressure. Sent from my iPhone using Classic Zcar Club mobile

I did open up my fuel pump control relay last week and it looked nice and shiny on the inside. I could not see any damage. Sent from my iPhone using Classic Zcar Club mobile

attached pic of the values. there are 2 different readings per test. Used 2 meters to test with. 95-91 and 93-92 my readings were very different between the 2 tests still need to do the 97 to 91 test

Set dial on ohms 2M. All relay tests came out to .000. Except 1 it fails. Sent from my iPhone using Classic Zcar Club mobile

More info on issue. So letting the car sit for about 10 minutes, fuel pressure still at 20psi. I started it up and fuel pressure at 48 psi and fuel filter is filling up with gas. Sent from my iPhone using Classic Zcar Club mobile

Thank you for the very detailed reply, i will need to retest my relays to get a curate info as requested. I did Use a Electrical Connector cleaner from AutoZone before reading the suggestion by another members post. Another issue it seems im running into is that my fuel pump is not pumping as it should. At cold start car starts normally, let it warm up for a good bit. I drove it around my neighborhood, about 2 miles and it started struggling. when i pulled up to my house i checked the fuel pressure and it was at 20psi and clear fuel filter by the pump was 3/4 empty. Yes there is gas. same thing that happen before but i thought i had ran out of gas. Gas Gauge is Semi faulty so i just added another 5 gallons of gas the first time it happen.