RXrick

Hi guys,

I've searched the FAQ page and didn't see an answer to my question about fuel pump issues with the GSL SE (13B) model.

When the ignition is on, does the fuel pump run? Can you hear it? I know this is true with the 12A but is is also true with the 13B?

I suspect my fuel pump stopped working or is clogged. I've already replaced the fuel filter. (Pump is $350!) Yes, I have spark.

Thanks for reading.

diabolical1

iTrader: (3)

answers seem to be in this one: https://www.rx7club.com/1st-generati...gsl-se-906361/

it may be worth it just to remove the pump and test it off the car if you remain unsure.

Maroochy

You should be able to hear it. I've got an '84 GSL-SE as well, so I've been through a lot of the non-starting issues lately too. You can use a fuel pressure tester to check if your fuel pump is delivering correct pressure to the engine without having to remove it. Buy a kit (I bought , much cheaper on Amazon). The FSM (free http://wright-here.net/cars/rx7/manuals.html) or a Hayne's manual will give you the procedure, but it's relatively quick and simple.

RXrick

Thanks for all your help. I’m beginning to feel the problem may not be mechanical but electrical.

How can I test the pump electrically without removing it? What voltage goes where? How do I access the pump for this test? From the floorboard? From underneath?

If it’s not getting electricity, then I can explore the suggestion about the cut relay, etc.

Thanks for reading!

RXrick

Forgot to add, I don't hear the pump humming or anything when the ignition is on or the engine is cranking.

Bluecoop91

iTrader: (14)

There is a fuel pump test circuit that will allow you to verify that the pump is working. You can also flow test the pump without turning the engine over. You'll have to do a forum search.

DreamInRotary

iTrader: (49)

1. Pull the rear storage bin behind the driver's seat.
2. Dig around in there till you find the two-wire set that goes through the grommet of the floor board
3. Unplug that thing from the fuel pump and turn the key on
4. Test that connector with a multimeter and see whether it has power or not
5. Determine if the pump is dead or there's a wiring issue
6. Have more fun diagnosing after doing the preliminary diagnoses I just stated
7. Find the problem
8. Fix the problem by creating a solution
9. Be a happy camper and enjoy your 7 again
10. Be happy you don't have to hear the wife complaining about how much time you're spending on your car anymore

Bluecoop91

iTrader: (14)

I would use the fuel pump test circuit first. It is easily accessible in the engine bay. Cheers!

andernamen

iTrader: (2)

Under the hood, near the air flow meter is a connector with black rubber around it. Put a jumper wire in there, turn the key but don't try to start. Listen behind the drivers seat and you should hear something. If not, you most likely have a clogged fuel system or electrical problem. There is a relay under the passenger footwell where the ECU is.

RXrick

I found the two wires that power the pump under the storage bin behind the driver's seat and with the ignition switch ON (but engine not cranking) VOM reads 9V. Should it be be 12V?

No hum, no vibration, no sound of life with ignition ON or with the engine cranking.

Ended up pulling the pump out and hot wired it directly to the battery. With fire extinguisher in hand, results = nada. Struck it lightly with a hammer and still nothing. Conclusion: dead pump in the middle of the road, er floor.

Atkinsrotary and Mazdatrix have an exact OEM pump with all the trimmings (new bracket, hardware, etc.) for $370 and $340 respectively. Then I found AutoPartsWarehouse selling what looks damn close to the original but without any trimmings for $88 (just the pump.) I'm afraid this session is going to time out so I will post this now and continue the story...

RXrick

Pump from Auto Parts Warehouse: Spectra, $88.

Spectra SPISP1186 Fuel Pump | Auto Parts Warehouse

Compare that to atkinsrotary OEM pump (image) with all the trimmings.

What do you guys think? I'm batting 50/50 with Auto Parts Warehouse...

I have more story about the test plug by the air filter...

Stay tuned

Bluecoop91

iTrader: (14)

PM sent.

RXrick

DreamInRotary — looks like I may be on #8

andernamen — I found two connectors there (one black with rubber and one just a female plug) I think this is where I can jump the wiring connection to prime the fuel system before trying to crank and start the car? The fuel line probably has no fuel in it anymore... What does the relay under the passenger carpet do for me? How do I test it? Do I need to test it?

andernamen

iTrader: (2)

I doubt the Circuit Opening Relay is bad. I would concentrate on the pump itself. The black connector with rubber on it will cause the pump to run when the key is on. Sounds like you need a new pump. But don't overlook the tank, make sure that is free of rust or you will trash the new pump as there is no filter between the tank and pump inlet, just some plastic screens.

wahootee

iTrader: (50)

I second this.
On the SE you will not hear the pump running when you turn on the key like the 12A cars. it only runs when cranking or running.
So, you need to do what anderman says and use the bypass connection up by the AFM with a jumper wire to hear if the pump kicks on (with the key on).
If it does kick on then you 've got other issues, I would suggest like I mentioned in another fuel pump thread to check the mircoscreen filter (not the large canister one) inline to see if it is plugged full of crap. If it is, clean it out and reinstall . that causes a lot of problems for folks and its the last thing them seem to check after tearing the car apart etc...
Hope that helps and listen to anderman and use the jumper wire/bypass connection.
Could also be your AFM flapper door.
Recommend you download the factory service manual and follow the steps laid out there. Its a "by the numbers" procedure and will save you a lot of time here asking questions about specs and procedures.
Good luck.

RXrick

Thanks wahootee for the advice. I decided against a used pump and bought an aftermarket from auto parts warehouse. Someone with an SE purchased one and his review claimed it works 100%. It is suppose to be delivered Saturday. Once installed, I will jump the connector as anderman suggested and we'll see what happens. Here are some pics of this project (new filter and old pump.)

wahootee

iTrader: (50)

The microscreen cone filter I was describing is inside the inlet tube on the r. side of your pump pic. If it is not there then it has been removed at some point. it is inserted into that inlet tube.

Also might want to pop the plastic cover off the pressure regulator on that other end and see if the screw has come loose. and/or tighten it back up. When you have it off you can suck or blow air through (by mouth not by compressor and see if the inner diaphragm is good or shot before you put it all back together. You might need a new one of those also.

RXrick

Received the new aftermarket pump yesterday and compared it to my original and I see a big difference in size.

Before I proceed, do you think this new pump (size) is going to work? Another SE person attested that it would work but he didn't mention if he had to modify anything (bracket, etc.)

Maybe I should re-consider and purchase a used OEM pump? What do you guys think? (see photo)

Thanks for reading and all your help.

andernamen

iTrader: (2)

Should have come with a thick piece of rubber that wraps around the new pump. Works just fine that way.

RXrick

@adernamen The pump did come with the rubber strip but the difference in size and the fact there was no specs on the pressure/flow (and that I don't like taking chances on generic aftermarket parts if I can find an OEM part) I decided on a used pump that is nearly identical to my OEM.

I recently renovated the oil cooler (no more leaks!) and now the car won't start. I just want to get my "7" on the road again without any unnecessary mistakes.

Thanks for your and everyone's help and advice. I really appreciate it.

andernamen

iTrader: (2)

I can relate. My Uncle had mine for ten years, five of which the car sat with a blown motor (overheating from a clogged radiator led to the engines demise). It was a real thrill to get the car back and then to get it back on the road. I had to completely go through the fuel system including dropping the tank and clearing out a clogged suction line. Good luck with yours.

wahootee

iTrader: (50)

Working on the oil cooler should have had zero effect on anything relating to the fuel system. In other words, if it was running before you began your oil cooler work, it should have started afterwards. The 2 are not related.

As said before in another post, you have to use the thick rubber strip wrapped around the pump. You might have to use both the old and new because of the size difference.

RXrick

Yeah, I know the two are not related. It was just that I finally fixed one problem and because the car sat so long now I have another.

RXrick

I bought a used pump and received it today. I compared the inlets? and they are quite different. I don't know anything about fuel pressure and flow but I just want to ask anyone's opinion of if / how the difference in diameter can effect the performance of the car (fuel injection pressure / flow, etc.) See photos.

Thanks for reading and your opinions.

RXrick

Good grief. And I thought my RX7 needed a paint job! Someday, our cars will be worth our investment. But not sure if it will be in our lifetime :-)