Fuel Pump Help?
#1
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Car: 85 IROC
Engine: 305 TPI
Transmission: 700R4
Axle/Gears: 3.42 Std. (3.73 posi, next winter)
Fuel Pump Help?
I have to change out the fuel pump on my 85 305TPI. I can't seem to get more than 25-30 psi at the rail and it drops to nothing within seconds of turning the car off. I have a new Holley adjustable regulator, new injectors, all new o-rings and do not smell fuel leaking anywhere. The filter is fairly new too. I have tested the pressure driving also with same results. (I'm assuming it's the pump, don't know what else it could be)
With that said, I need to drop the fuel tank to get to the pump, my question is;
Has anyone done this without having to drop the rear-end out of the car?? I looked back in the records that the P.O gave me and found where he paid a mechanic to change the last one, the receipt only states removing the exhuast and about an hour labor for the pump install, obviously they didnt drop the rear end for 1 hour labor...
Any input from anyone that has done this??
With that said, I need to drop the fuel tank to get to the pump, my question is;
Has anyone done this without having to drop the rear-end out of the car?? I looked back in the records that the P.O gave me and found where he paid a mechanic to change the last one, the receipt only states removing the exhuast and about an hour labor for the pump install, obviously they didnt drop the rear end for 1 hour labor...
Any input from anyone that has done this??
#2
Re: Fuel Pump Help?
It might be leaking down in the tank, there might be a rubber section that hooks the pump to the line.
You have to unhook the shocks & lower the rear axle, not remove it.
You have to unhook the shocks & lower the rear axle, not remove it.
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Car: 85 IROC
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Axle/Gears: 3.42 Std. (3.73 posi, next winter)
Re: Fuel Pump Help?
Is there any way to test the pump for proper operation when I get to it?
#4
Re: Fuel Pump Help?
The leak I'm talking about is inside the tank.
I'd pinch off the return line, cycle key, watch bleed down rate, if nothing changes, then I would cycle the key & quickly pinch off the feed line & watch the bleed down. If it doesn't bleed down & theres no leaks anywhere, the its leaking down inside the tank.
I'd pinch off the return line, cycle key, watch bleed down rate, if nothing changes, then I would cycle the key & quickly pinch off the feed line & watch the bleed down. If it doesn't bleed down & theres no leaks anywhere, the its leaking down inside the tank.
#5
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Re: Fuel Pump Help?
Also you might search this forum for putting a hatch in the back floor to get to the pump when ever you want.
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Car: 85 IROC
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Axle/Gears: 3.42 Std. (3.73 posi, next winter)
Re: Fuel Pump Help?
I'm hoping there's has not been a hatch put in, trying to keep it as close to original as I can.
I will try the testing with the line pinched later this week.
Thanks for the input!!
I will try the testing with the line pinched later this week.
Thanks for the input!!
#7
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Re: Fuel Pump Help?
I do not have a hatch in mine ether.
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Re: Fuel Pump Help?
The leak I'm talking about is inside the tank.
I'd pinch off the return line, cycle key, watch bleed down rate, if nothing changes, then I would cycle the key & quickly pinch off the feed line & watch the bleed down. If it doesn't bleed down & theres no leaks anywhere, the its leaking down inside the tank.
I'd pinch off the return line, cycle key, watch bleed down rate, if nothing changes, then I would cycle the key & quickly pinch off the feed line & watch the bleed down. If it doesn't bleed down & theres no leaks anywhere, the its leaking down inside the tank.
Also, is there a "relay" under the hood somewhere for the fuel pump? I can hear it cycle when I turn on the ignition, as soon as that relay cycles off, the pressure drops immidately.
Juat trying to rule out everything before I drop the tank
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Car: 85 IROC
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Axle/Gears: 3.42 Std. (3.73 posi, next winter)
Re: Fuel Pump Help?
OK, finally got the tank out. Not that hard just time consumming. Getting the fill neck out is the hardest part.
The rubber line connecting my pump to the metal line inside the tank was so bad that the rubber was coming off, so I'm pretty that was where my leak was. Jusy need to get the new pump and parts to go with it and I hope to put it back together next weekend.
The rubber line connecting my pump to the metal line inside the tank was so bad that the rubber was coming off, so I'm pretty that was where my leak was. Jusy need to get the new pump and parts to go with it and I hope to put it back together next weekend.
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Axle/Gears: 3.42 Std. (3.73 posi, next winter)
Re: Fuel Pump Help?
The leak I'm talking about is inside the tank.
I'd pinch off the return line, cycle key, watch bleed down rate, if nothing changes, then I would cycle the key & quickly pinch off the feed line & watch the bleed down. If it doesn't bleed down & theres no leaks anywhere, the its leaking down inside the tank.
I'd pinch off the return line, cycle key, watch bleed down rate, if nothing changes, then I would cycle the key & quickly pinch off the feed line & watch the bleed down. If it doesn't bleed down & theres no leaks anywhere, the its leaking down inside the tank.
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Car: 1988 Iroc-Z tpi 5.7
Engine: ls2
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Re: Fuel Pump Help?
what in gods name is that! ive never seen a fuel line disintegrate like that before now the question is you sure the pump and or the the hose was replaced ? or was it a quick slap in ? in the history of replacing fuel pumps ive never encountered that before... hmmmm get to replacing and cleaning my friend. btw everyone likes to drop the tank to replace the fuel pump. on my iroc i have the door because as we all know it you be there again and im not dropping the tank on the side of the highway...
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Car: 1985 Iroc-Z
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Re: Fuel Pump Help?
I am going to be changing my fuel pump soon. What fuel pump are you using as a replacement?
#17
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#18
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Re: Fuel Pump Help?
OK, guys got a question...
Got my new pump and about to install it, here's my question though..
Since I dropped the tank, I just want some piece of mind before I put the tank back in, is there any way to test the pumo beforeI pu it in? can i just put 12v to it to make sure it runs?
Got my new pump and about to install it, here's my question though..
Since I dropped the tank, I just want some piece of mind before I put the tank back in, is there any way to test the pumo beforeI pu it in? can i just put 12v to it to make sure it runs?
#20
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Car: 85 IROC
Engine: 305 TPI
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Axle/Gears: 3.42 Std. (3.73 posi, next winter)
Re: Fuel Pump Help?
Does it have to be in the tank to do this? Cause its installed on to the sending unit and when I plugged into the car and turned on the ignition, I got nothing.
I did check the voltage at the connection on the body and it gets 12v for about 2 seconds when i turn on the ignition
I did check the voltage at the connection on the body and it gets 12v for about 2 seconds when i turn on the ignition
#21
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Engine: 1 BA 305 TPI
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Axle/Gears: 3.42
Re: Fuel Pump Help?
I just connected mine to the car wiring and turned the key on. Don't leave it on long. Just check to make sure the pump kicks on then turn the key off. You don't want to burn the pump up by running it dry too long.
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Axle/Gears: 3.42
Re: Fuel Pump Help?
Does it have to be in the tank to do this? Cause its installed on to the sending unit and when I plugged into the car and turned on the ignition, I got nothing.
I did check the voltage at the connection on the body and it gets 12v for about 2 seconds when i turn on the ignition
I did check the voltage at the connection on the body and it gets 12v for about 2 seconds when i turn on the ignition
#23
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Car: 85 IROC
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Transmission: 700R4
Axle/Gears: 3.42 Std. (3.73 posi, next winter)
Re: Fuel Pump Help?
What should I get when I ohm the pump? I ohmed my old one which still came on and got aroun .60. The new one only gives me about .05
I'm thinking I got a bad one....
I'm thinking I got a bad one....
#24
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Re: Fuel Pump Help?
OK, got it workin!! Had a bad connection. i didnt use the new plug that came with the pump at first. Changed that out with the new one that came with and it works now!
I just used standard wire crimps as the previous install had on the ground wire only.
Getting it all put back together in the tank to re-install. Gotta work tonight so the tank install will have to wait until tomrrow.
I just used standard wire crimps as the previous install had on the ground wire only.
Getting it all put back together in the tank to re-install. Gotta work tonight so the tank install will have to wait until tomrrow.
#25
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Re: Fuel Pump Help?
Here is the pump I found. So far so good. Good price and super fast shipping. I should know by tomorrow night or Monday if it works good.
http://www.highflowfuel.com/i-520971...1985-1997.html
http://www.highflowfuel.com/i-520971...1985-1997.html
#26
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Re: Fuel Pump Help?
Fuel pump is in and car is running great. Just need to get my exhaust put back together this week.
The pump took care of my pressure issues. holds pressure now. I beleive it was a combo of the pump going out and that little hose from the pump to the sending unit (it was bad too).
Anyways, I'm a happy camper. Thanks everyone for the input. I know it seems like a small project, but i had to put it on hold all winter due to work and $$.
Now to figure out my next project to tackle....
The pump took care of my pressure issues. holds pressure now. I beleive it was a combo of the pump going out and that little hose from the pump to the sending unit (it was bad too).
Anyways, I'm a happy camper. Thanks everyone for the input. I know it seems like a small project, but i had to put it on hold all winter due to work and $$.
Now to figure out my next project to tackle....
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