BigJim

So im pretty sure my fuel pump is either shot, or has a bad connection. Check the fuel pump fuses and they were fine. Heres what happened. Driving down the road and the engine dies. I think, hmm wtf, try to start it and it fires for half a second then dies. I stop turn the key off then on, and i dont hear the fuel pumps normal noise, instead i hear a clunk in the tank. The clunk is what leaads me to believe it may be bad wiring, similar to how starters clunk when they have a bad connection. So, whats the easiest way to get access to the fuel pump, what voltages should it read, and also if i do get a new fuel pump what should i get. Heres the list of mods.

Streetport from KDR
downpipe, high flow cat, catback
powerfc
m2 air box

dynotuned to 310 hp.

thanks for the help guys

BigJim

soi just went and messed around with it. Took that cover in the hatch off and checked continuity between the 4 posts on the connector on the tank. All 4 had continuity between each other. This is a bosch fuel pump but im not sure which one. the FSM said for a stock one if there is continuity then you need a new fuel pump. Does this hold true for the bosch one? If so which pump should i get as a replacement

BigJim

anyone at least know what fuel pump i should run?

rotaryjunky

https://www.rx7club.com/3rd-gen-archives-73/some-fuel-system-ramblings-578521/

I think this is the word on it.

rotaryjunky

Can you run 12V to it to check if it runs? I ended up just running a wire from my battery to my fuel pump and hooking up a switch, but thats the civic!

BigJim

i tested for power at the connector and it has power there.

Mahjik

iTrader: (1)

http://www.rx7.com/store/rx7/fdfuel.html

BigJim

if i end up getting the supra tt denso fuel pump will i need a fuel pressure regulator? The car may very well have one on it already since it had an aftermarket bosch pump. Wheres typicall install locations of a fpr

BigJim

oh and in case your wondering how little i know abuot my car, the fuel pump broke on the 8th day i owned it. At least it went a full week though.

rotaryjunky

The stock factory FPR should do it. A fuel pressure gauge might be a good idea, though.

Section8

iTrader: (6)

I replaced my dead FP with a walbro hi flow unit, it was cheaper than the stock FP too. quick fix, takes about 30 minutes, and thats including jumping the electrical to prime the system.

sbnrx7

iTrader: (4)

Have you chekced to see if the pump is making a sound when you jump the F/P to the ground in the diagnosis box? Just in case you didn't know, if you're using the stock relays to power your fuel pump, the fuel pump doesn't kick on until the starter is engaged. Simply turning the ignition switch to the "on" position doesn't turn on the fuel pump. Follow the proceedure outlined on page F-100 in the FSM to test the fuel pump. All you'll need is about a 2" length of wire to "jump" the terminals.

BigJim

sbnrx7, no i was not doing the jumper thing, but prior this, when i turned the key on, the fuel pump did turn on. Every time before i started my car i would turn the key and wait for the pump to stop pumping, then start it up and it started alot quicker like that than if i just got in and cranked it over. So maybe the prior owners changed something, it does have a different fuel pump in it than stock

sbnrx7

iTrader: (4)

Hmmmm. Ok. Then what I suggest is to refer to page F-108 and F-60 in the FSM. This shows the stock setup for powering the fuel pump. I'd compare this to what you actually have before going forward. I've seen some creative wiring done by previous owners that caused alot of problems. I have not personally changed the fuel pump in an FD but it looks like a pain in the *** according to the FSM. I would go through and test all of the components(including continuity at the ECU harness) associated with powering the fuel pump to eleminate them and only pull the gas tank as a last resort.
I had a similar problem where the pump failed and was getting ready to pull the tank. I researched the FSM one last time and found on page F-60 a detailed wiring schematic and discovered it was a problem with the ECU and nothing else. The 1T terminal on my ECU went inop and was not closing the circuit opening relay. Can't tell you how happy I was that I didn't have to change the pump.

YZ250FD

fyi: the dinky little wires often result in excessive voltage drop, and the electrical plug at the tank cover gets corroded

I re-wired the whole thing and ditched the corroded plug, my voltage immediately jumped up