So if the ZX should have a fuel pump relay why don't you hook one up yourself, or is it not supposed to/didn't have one? If this is TRUELY the only thing that is not right, then it must be the reason why its not right

 

Monday Daniel is wanting to come get the car and take it back to Tulsa...

If I knew where to run the wire I would, but I don't. That's why I am asking for help...

 

i still think its a ground ....

 

how? why would a ground only affect the car when it's in gear? in neutral the car fires up and idles/revvs all day long...

what ground would affect this? please give reasoning behing your thoughts...

 

ok, so after much trial and error, installing an adjustable FPR thinking that the Fuel Pressure was too high, adding a fuel stabilizer, and then cranking with the relay off, we went to start and discovered that there is no fuel coming into the system. I pulled off the hoses on each side of the FPR and found both are dry, so there is no fuel entering or leaving the system. I double-checked and the wires for the fuel pump and the air regulator are properly switched, but that isn't fixing the problem.

We have resulted that the problem lies with pin 20, despite the fact that everyone says it isn't necessary. We looked and figure that the best place to hardwire the pin to would be Fuel Pump Relay 1 on the passenger side of the car. However, there are 5 wires going into the relay, and I am unsure which one to tap into. Any help?

 

Also today the wastegate popped when we tried to start it after putting on the FPR.

I'm about just ditch this engine and do a v8 swap with everything that's been going wrong

 

Things are only going "Wrong" because you dicked with it...


Take a deep breath, collect your thoughts and fix what was not broken until you decided to "Upgrade" it


Rod.

 

Well the FPR wasnt really meant as an upgrade, but only to help limit the fuel because the plugs were wet and that was the only, quickest and cheapest (since we already had an FPR laying around) to attempt to fix the flooding.

 

umm not sure how that reply is helping the situation, but okay...

forums are for helping people. When we couldn't figure out the problem ourselves, we posted for help. People replied with suggestions, we tried them, and they made no difference. It's not a ground, because the engine fires up fine, just isn't getting fuel after a bit. Just need suggestions why, and then we will fix it and be fine...

 

My thoughts exactly. I put together that Excel spreadsheet / 280zxt wiring / Z31 wiring ZIP file for a reason. If the directions are followed CORRECTLY, the car should run fine (if it was running fine before). I did exactly what I have said in my Excel spreadsheet to my Z & have had ZERO probs since. If you're not getting fuel, your fuel pump isn't working... from the previous posts I still can't tell if you fixed PIN20 to now run to the CORRECT PIN 108??????

 

I told you Pin 108 was always correct. I just had Pin 20 tied into it, which has since been removed...

 

You might have toasted something. The purpose for PIN 108 is to allow the ecu to open the ground to the fuel pump relay when the fuel pump should be working (thus turning on the fuel pump). PIN 20 looks to be a power wire to the fuel pump relay.... you tied a + wire to a - wire.....

 

Hmm that wouldn't be good. I am looking at the write-up from HybridZ and comparing it you your Excel Spreadsheet, and the only difference I am seeing is that on your sheet it says to just switch the wire from pin 16 with the wire from pin 108 so that the Fuel Pump and Air Regulator are operated differently. On the HybridZ write-up, it tells to switch the wire from pin 108 to pin 16, but to cut the black wire going into the Fuel Pump Relay 1 and to run it to pin 108.

Does this just bypass the relay doing it their way or what?

 

Yep... that's what you're supposed to do. You cut the black wire just after the fuel pump relay and run it (the wire still connected to the relay) to pin 108 on the ECU.

No... like I said before THE ECU now grounds the fuel pump relay, and you also now need to ground the fuel pump to the body.

 

oh ok... guess I missed that part... let me do that in the morning and we will see where we stand...

 

and I go from the relay to the ECU, not the wire to the ECU?

 

Yes...

Cut wire going to PIN 108 & connect it to a longer spare piece of wire... run that wire over to the passenger side dash. Cut the black wire on the fuel pump relay (fpr). The black wire STILL ATTACHED to the fuel pump relay is then attached to the wire you just ran from ECU PIN 108.

In other words...

You leave the black fpr wire going into the body wiring harness dangling unconnected. If you connect PIN 108 to that wire, you ground a ground and the fuel pump no workie.

This should be pretty simple.

 

yup sounds much better... will do that in the morning and see how it goes...

 

ok, that is done. Now which wire do I ground to the chassis for the fuel pump? When I removed the cover in the back of the car, I see the black and yellow wires coming up next to the fuel lines, but that black wire already looks grounded.

Just wanting to do this right without making major mistakes...

 

There's only 2 wires to the fuel pump... a green one & a black one. Green is + & black is -. Or you can just look on the fuel pump terminals for + & -

 

where is that at? I think I am looking in the wrong spot then...

 

neverming scratch that, looked it up in Hayne's

 

ah yes... a Haynes Manual.

 

Bump again.... Is the car running as it should now?

 

still couldn't get the fuel pump to work using that method... I dunno if there is something wrong with the ECU or what.

Just to see what the problem was, I hardwired the Fuel Pump today with a toggle switch and when turned on and pressurized the car starts, but now does not want to idle. As long as my foot stays on the gas, I am able to drive it around no problems. However, it cannot be driven this way, as is apparent.

Also, the last time I started it, it continually backfired until I shut it off. Acted as though it was still starving for fuel... going to check timing tomorrow when I can get a friend to help me, any other ideas?