Stock fuel pump. Urgent!!!
08-05-04, 07:41 PM
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Stock fuel pump. Urgent!!!
Quick. I need to know if the fuel pump is internal or external. The car is a 1985 GS.
Last edited by Misthael; 08-05-04 at 07:45 PM.
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08-05-04, 08:25 PM
#9
fuel pump
Very straight forward. In order to disconnect the electrical harness you remove the
driverside storage compartment. You will find the connector coming thru the floor board, just unplug it. If the replacement pump has a universal connector, cut the one from the old pump and use butt connectors for your new connection. Other than that you remove the plate that holds the fuel pump in place, secured by approx 3 bolts, use 10mm socket to remove. Recommend that you replace the rubber hoses that go to the pump at same time and install new fuel filter. Have abolt or use pinch off tool to keep fuel from pouring all over your face when you remove the line that comes from the tank. Ifit is a aftermarket pump it will have a seperate ground, make sure that attaches to a very clean piece of metal.
Have fun. rx7doctor
driverside storage compartment. You will find the connector coming thru the floor board, just unplug it. If the replacement pump has a universal connector, cut the one from the old pump and use butt connectors for your new connection. Other than that you remove the plate that holds the fuel pump in place, secured by approx 3 bolts, use 10mm socket to remove. Recommend that you replace the rubber hoses that go to the pump at same time and install new fuel filter. Have abolt or use pinch off tool to keep fuel from pouring all over your face when you remove the line that comes from the tank. Ifit is a aftermarket pump it will have a seperate ground, make sure that attaches to a very clean piece of metal.
Have fun. rx7doctor
08-05-04, 08:39 PM
#11
Hey,
The fuel pump is mounted on the underside of the car, between the car and a metal plate that's secured on with four bolts. The line goes from the tank, to the filter, to the pump if I remember correctly. Follow the line after the filter and you'll find the pump.
The fuel pump they give you is probably not going to be a direct fit, so be prepared to do some modding.. I notice that you have a GS the same as me, so yours is probably exactly the same setup. The wire for the fuel pump goes into the car and comes out on the underside of the driver's side storage bin. You have to remove this bin to get at the white plastic connector for the fuel pump. Depending on the pump they give you, you'll probably have to cut the connector off (leaving yourself a few extra inches of wire after the connector) and solder those to the wires from the pump.
The pump, as you've guessed by now, is definitely external. There wasn't a first gen built that I know of that had an internal pump, with the exception *MAYBE* of the -SE... I've never worked on an -SE but I know they need higher pressure pumps than ours.
The only thing you have to do to access the pump is jack up the back of the car... you don't need to move the tank at all. Don't forget to change your fuel filter while you're under there, it's worth the five bucks!
Good luck. If you have any questions, run in and post them, I'll try and keep an eye out at work tomorrow.
Jon
The fuel pump is mounted on the underside of the car, between the car and a metal plate that's secured on with four bolts. The line goes from the tank, to the filter, to the pump if I remember correctly. Follow the line after the filter and you'll find the pump.
The fuel pump they give you is probably not going to be a direct fit, so be prepared to do some modding.. I notice that you have a GS the same as me, so yours is probably exactly the same setup. The wire for the fuel pump goes into the car and comes out on the underside of the driver's side storage bin. You have to remove this bin to get at the white plastic connector for the fuel pump. Depending on the pump they give you, you'll probably have to cut the connector off (leaving yourself a few extra inches of wire after the connector) and solder those to the wires from the pump.
The pump, as you've guessed by now, is definitely external. There wasn't a first gen built that I know of that had an internal pump, with the exception *MAYBE* of the -SE... I've never worked on an -SE but I know they need higher pressure pumps than ours.
The only thing you have to do to access the pump is jack up the back of the car... you don't need to move the tank at all. Don't forget to change your fuel filter while you're under there, it's worth the five bucks!
Good luck. If you have any questions, run in and post them, I'll try and keep an eye out at work tomorrow.
Jon
08-05-04, 09:12 PM
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I'm still not sure I need to change the fuel pump. I'm going to call the guy who rebuilt my carb tomorrow and see if he will adjust the floats for me. He should since he rebuilt it and it's not working properly. Can you adjust the floats while the carb is on the car? Or do you have to take the carb apart?
08-05-04, 09:51 PM
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Car stops going faster after 4500 rpm. It's being starved of fuel. The floats aren't very full. I've checked the windows. They are higher now that I put on a new fuel filter, but still not even halfway full yet. Only happens under load and only in 3rd 4th and 5th gears around 3500 to 4500 rpm. Pulled the fuel line and made sure the pump worked. It did. I don't have the tools ot check the fuel pressure so I have no idea about that. That's about it.
08-05-04, 10:10 PM
#15
From what I've seen the stock pump either works or it doesn't, but I could be wrong.
Be warned though, any mods he's made to the carb could require more fuel. This isn't my area of expertise, we should becon Carl or Sterling in here :P
Also, replacement fuel pumps often put out more pressure than the stock ones, which can be a bad thing. If you do end up buying another pump, check the stats on it to see if it's delivering more than 3-4psi.. if it is, you should probably get a fuel pressure regulator and pressure guage. I replaced mine with a Mallory Comp 70 because I have an Rx7Carl carb that needs more fuel at the higher end. I've got a Holley pressure regulator because the mallory (which is the lowest mallory I could find and is actually rated for marine use) still pumps 6psi standard, which would overload the carb in an instant.
Before you go changing fuel pumps, talk to Carl or Sterling. They'll know the questions to ask you to get more details about your situation and properly diagnose your problem.
Fuel not halfway in the bowls though... floats seems like a good guess to me.
Jon
Be warned though, any mods he's made to the carb could require more fuel. This isn't my area of expertise, we should becon Carl or Sterling in here :P
Also, replacement fuel pumps often put out more pressure than the stock ones, which can be a bad thing. If you do end up buying another pump, check the stats on it to see if it's delivering more than 3-4psi.. if it is, you should probably get a fuel pressure regulator and pressure guage. I replaced mine with a Mallory Comp 70 because I have an Rx7Carl carb that needs more fuel at the higher end. I've got a Holley pressure regulator because the mallory (which is the lowest mallory I could find and is actually rated for marine use) still pumps 6psi standard, which would overload the carb in an instant.
Before you go changing fuel pumps, talk to Carl or Sterling. They'll know the questions to ask you to get more details about your situation and properly diagnose your problem.
Fuel not halfway in the bowls though... floats seems like a good guess to me.
Jon
08-05-04, 10:13 PM
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There were no modifications to the carb. Just a rebuild. I know if I have to replace the fuel pump to regulate it to 4psi. I just don't know what's goin on.
08-05-04, 10:36 PM
#17
A simple test for volume which is more important than pressure is to get a clear 2 qt container and take the feed hose off and activate the fuel pump. you should get at least
1.5 qts of fuel within 1 minute. If you less than that you have a bad fuel pump or restriction in the line. Fuel filter or kinked fuel hose or bent metal line. Just a question, do you have the stock exhasut with a cat on it? rx7doctor
1.5 qts of fuel within 1 minute. If you less than that you have a bad fuel pump or restriction in the line. Fuel filter or kinked fuel hose or bent metal line. Just a question, do you have the stock exhasut with a cat on it? rx7doctor
08-05-04, 10:48 PM
#19
Do the things in my previous post then. I was looking to see if you had a plugged cat. Since
you had a rebuild just done, viper is probally right with the float level being set too low.
Does not hurt to do alittle trouble shooting though. It's good experience for you and will
help you when you encounter other problems. Good luck rx7doctor.
you had a rebuild just done, viper is probally right with the float level being set too low.
Does not hurt to do alittle trouble shooting though. It's good experience for you and will
help you when you encounter other problems. Good luck rx7doctor.
08-06-04, 10:28 AM
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How exactly am i supposed to activate the fuel pump? Is the fuel pump supposed to pump in the accesory position? Fuel was only coming out of the fuel line when the engine was running and without fuel the engine died real quick so how am I supposed to keep the pump on? Maybe I'm just doing something wrong. Gonna go out and mess with it.
08-06-04, 10:53 AM
#21
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Good question my dear grasshoppa. Yours is an 85, right? There is a fuel pump relay that will prevent the fuel pump from working after a few seconds of turning the key to "on", and until you actually crank the engine. To test pump therefore you must bypass relay. Go to http://www.wankel.net/~krwright/cars/rx7/85_manual.html and click on the Fuel and Emmissions chapter I think it is, and look for the section on the fuel pump. It tells you how to test it, which includes the procedure for bypassing the relay. Good luck.
08-06-04, 11:50 AM
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Never mind. I found the relay and did the volume test. So now I know. It's the floats. Just got off the phone with the guy who rebuilt it. He set the floats to stock specifications and it was flooding like crazy so he had to adjust the floats lower so it wouldn't flood so now the needles have probably fixed themselves/settled in and the floats are set too low. Going to take the carb in Monday so he can set them back to stock specs. Free too since he just rebuilt it and all. I'm kinda happy now that I know what it is. But the clutch still slips occasionally. Oh well. I think I'll concentrate on upgrading my computer for a little while. Get back into my car next summer.
Last edited by Misthael; 08-06-04 at 12:02 PM.
08-06-04, 11:52 AM
#24
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Ok. Check this thread out, it has pics which shows exactly where it is and how to do the bypass thing. https://www.rx7club.com/1st-generation-specific-1979-1985-18/84-85-fuel-pump-relay-trick-273215/
Oh! too slow. Never mind.
Oh! too slow. Never mind.
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