Shift2Drift38

Hey guys, new here. Just picked up an NA 86 RX7. Knew right off the pump was bad because it wasn't kicking on. Pulled the old one, tried to jump it to see if it'd kick and nothing. So, I put a new one in, new strainer, new fuel filter.

So after all this, I pull the pressure line (one that runs from the top of the fuel filter to the rail). Just keyed it on, and nothing. Cranked a couple times, zero fuel. Lost, I know the new one works because I ran power to it right out of the box to be sure. I'm sure it's something electrical, maybe my wiring wasn't 100%? I do know the new pump now has a plug that has two wires running out of it. Black being ground that I looped around and grouned to the side of the assembly. The yellow being positive, that was butt connected to the blue wire, and on top of the assembly I just Color for color reattach in the trunk.

All the fuses under the hood are good, and I know it's not flooded due to the pump never working or kicking on to begin with.

Also, I pulled that fuel filter line, and checked for flow before I cranked the car at all, to prevent the chance of guessing whether or not fuel got through.

Any insight or tests would be great. Thanks!

diabolical1

iTrader: (3)

welcome to the board.

check the AFM.

Shift2Drift38

I'll be sure to do that, any way of testing it? I Googled it up since I'm extremely new to this Rotary stuff and Mazda's in general.

So I know I'm on the same page, the fuel pump in theory, should be sending fuel while cranking?

If that's the case, would it be effective to pull the fuel filter line, and use a catch can of some sort while the engine is being cranked to ensure it's sending fuel? Or will the ECU catch on to that and it's just a shot in the dark?

diabolical1

iTrader: (3)

yes, the pump is supposed to cycle on when cranking.

however, I may have spoken too soon. I didn't ask if you were getting spark.

at any rate, you should probably download a copy of the FSM. you can follow the procedure listed in it to check the AFM. that said, I think I read sometime in the past that you could perform a crude test of the AFM by unplugging it and then cranking the car to see if it fires for a few seconds.

satch

iTrader: (1)

Jumper the fuel check connector and this should turn on the fuel pump w/the key to on.

Shift2Drift38

Alright, from what I've researched so far, this fuel check connector, is on the passenger side strut tower. All I'll need to do is run a jumper wire (red) to it and just ground it to the negative battery?

Know it's sounds noob like, but electrical testing are waters I have seldomly tread, I only learned how to test a fuel pump out of the box yesterday lol.

And there's some sort of relay on the Drivers side (inside the car) to the right?

Anyone able to post a pic or two? Currently on my lunch, but will tackle this when I get home. Thanks guys, been super helpful so far!

satch

iTrader: (1)

The fuel check connector has two wires to it. Bridge the two two wires to each other generally by shoving the jumper wire into the back of the plug.

And make sure the 15amp Engine fuse is good as it powers the fuel system.

The Circuit Opening Relay is Yellow and Black and is located just underneath the dash and to the right of the steering column. Has five wires in all. Top row center wire, Black/White, would have 12 volts w/key to on and it is this wire that is powered by the Engine fuse.

Post #6 pic #1.

https://www.rx7club.com/2nd-generati...erence-671004/

Shift2Drift38

Alright, I'm searching for this connector, and the only thing I've found, is a single green connector on the passenger side. has 3 female inserts. the bottom of the 3 have blue wires running into them and the top female has a Black/White. Anyone able to point out where exactly this connector is?

Also, I unplugged the AFM, cranked on it, still zero fuel from the pump. 15A Engine fuse is good. Unplugged the 40A Eng Inj fuse just to see if "maybe" it was flooded before I got it. Nothing. Also, should I have an oil pressure reading while it's cranking? Just curious. Thanks guys!

satch

iTrader: (1)

The check connector is encased in a Black rubber boot and the plug is Yellow. It is part of the Emission harness. So, you locate the Pressure Sensor and its part of that harness. You could also jumper the bottom two wires in the Circuit Opening Relay (yes, that would be the Black wire and the Brown wire).

Shift2Drift38

Found it, was tucked and tied off underneath the airbox. Had to pull that out to get to it. Now, so I know I did this right... I took two test leads (alligator clips is all I had at my disposal). I bit on both female ends, and the other side I just tapped together. I did hear a switch or relay of some sort kick over with the key in the "ON" position, however, still no fuel pumped into my catch can. I did this both with the AMF Plugged in, cranking, and also with it unplugged, and cranking.

I'm lead to believe I need to recheck my wiring at the pump itself, and perhaps get rid of my butt connectors, and just hard wire it as a temporary test.

I did butt Connect the new fuel pumps Yellow wire to the blue power wire, and then butt connected color for color on the top side of the assembly.

I'll get to this asap, but if anyone has any other insight, like maybe the fuel resistor (which if I was seeing it right is directly under the airbox and bolted down.).

Thanks again for all the info so far, and the patience. I've done alot with Mitsu's and Honda, but man this Rotary is a whole different animal. Kind of a love hate so far haha.

satch

iTrader: (1)

An 86 NA would not have the fuel pump relay and resistor if that's what you're talking about as it's found on S4 turbo's and all S5's.

The Circuit Opening Relay will tell you what you need to know. The top left wire should have voltage w/key to start. The wire next to it gets voltage w/key to on. The wire to the top right, which is Blue, runs to the fuel pump so it needs to have voltage w/key to start, and it would also have voltage w/key to on and the fuel check connector jumpered as well. Again, jumpering the bottom two wires of the Circuit Opening Relay does the very same thing as jumpering the check connector. No power to the Blue wire means no power to the pump!

Shift2Drift38

Ok, so I'll just start from step 1, hardwire everything on the pump assembly to ensure it's all good to go, and from there I'll do that relay voltage test. I'll get back on here when I get home and let you know how it goes. Thanks a ton guys, I hate electrical, but just glad there's people that actually have straight forward answers.

Shift2Drift38

Having a hard time using the leads I have on the Circuit Opening Relay. So, if I just jumper the check connector under the hood, should I still read voltage on the Top Right (Blue wire) with the key in the "ON" position?

Also, after I rewired everything, I noticed after cranking I did get some (and I mean just enough to be damp on the hose tip) fuel back through the return line, but none from the pressure side.

satch

iTrader: (1)

Yes. And what exactly is the problem w/your leads as it relates to the relay?

Shift2Drift38

Alright getting 9 volts, to the Top Left, and Top Middle while cranking. Nothing on Blue. Currently jumpered at the check connector, and probing the wires from behind with my Voltmeter while plugged into the Relay.

As for my leads, being alligator clips, kinda hard to bite the inside for the plug : /

satch

iTrader: (1)

Is there voltage on the Blue wire w/the key to on and the jumper in place?

Shift2Drift38

Jumper is in place on the check connector. I assume I could just unplug it from the relay and test for voltage that way? If so, I'm getting no power to Blue. I've undone all the wiring to the fuel pump assembly just to check for power there and nothing.

I know the relay is getting power when I tap the jumpers together. Also, I noticed a buzzing, or humming noise, in the engine bay with the jumpers and the key to 'ON'.

Shift2Drift38

Take that back, Not sure how, but I have 11.9 volts to the blue now. Must have been a miscue on my end. Jumpers connected, and Harness plugged into relay, probed it from the back, and 11.9 showed up.

satch

iTrader: (1)

You can't measure for voltage on the Blue wire if the plug is not plugged into the relay as the job of the relay is to allow voltage to be passed to the Blue wire.. So with that said, there should be voltage on the Blue wire w/key to start and no jumper needed, and there should be voltage on the Blue w/the jumper in place and key to on. So, do you have both?

Shift2Drift38

Have 11.9 Volts with it jumpered.

Not Jumpered it goes crazy....

Key in "ON" position.

satch

iTrader: (1)

Nope.

"So with that said, there should be voltage on the Blue wire w/key to start and no jumper needed, and there should be voltage on the Blue w/the jumper in place and key to on. So, do you have both? "

Shift2Drift38

Crap... misread that first part, that would explain it.

Shift2Drift38

Alright, did it right this time.

Key "ON" with jumpers = 11.75 Volts (Think all the cranking and tests is taking a small toll on the battery lol)

Key "Start" (cranking) no jumpers = 9.5 volts.

Sorry about that Satch lol, thanks for the replies!