Fuel Pump Nonop after hose replacement?

MPDano · MPDano's Garage

Hi all,

Something weird happened over the weekend. I changed the fuel hose that connects the tank to the fuel pump and now it wont start. I disconnected one the CIS lines on the distributor and no fuel when cranking with key on, same thing after disconnecting the line going to the CIS distributor. I also am not hearing the short buzz noise from the pump when I turn on the key. Relay is jumped so it's not a faulty relay. Any suggestions or thing to try?

Leo

MountainShark · 12-02-2008, 05:42 PM

Jump relay you should be able to hear or feel both pumps run. If not running try cleaning all connections and grounds. Got GAS?? If pumps run you should be able to loosen fuel line to an injector and fuel will run out when you short relay. Mine seems to be easier to start after a pump or filter replacement if you jump the relay for several seconds just to clear the air out of the system.
Best of luck!

MPDano · MPDano's Garage

My relay is already jumped. We had to removed the relay since I was having another electrical issue. I am using 2 spades to jump the connections. I am not hearing anything from the pump as I used to. Could it be a fluke that the pump died at the time i replaced the hose? I have already pulled one of the lines at the CIS to verify no fuel. Tank is at least half full with 91 octane.

Landseer · 12-02-2008, 07:08 PM

How long has it been jumpered?

Not sure on yours, but on my 84's, jumpering the fuel pump relay starts the pump, key off, and it runs continuously until its unjumpered. Turning key has no effect.

Danglerb · 12-02-2008, 07:12 PM

How did you keep gas from pouring out of the tank while changing the hose, a clamp?

Did you take it off?

Do you have power at the pump?

MPDano · MPDano's Garage

Hi Mike, that would be my finger, then a quick change of the hose. Not the cleanest way to make the change but it works. I didn't check for power, I guess I should break out the meter and see if I get power to the pump connections. I did tap it a little to see if that helped but nothing. I checked my fuses and all look fine visually. Landseer, when mine is jumped it doesn't continuously run the pump except when the key is on. Then it usually runs for a few seconds only then back on when the engine fires up.

After changing the hose over the weekend, I did shoot some water on the plate holding the tank since it had caught a lot of fuel when I was changing the hose. Battery was disconnected and key was off so i don't think I could have shorted anything.

MrGST · 12-02-2008, 09:34 PM

Leo,
That pump may be a bit flaky. When we all worked on your car that Saturday, I had to tap it a couple times to get it to spin up. Try giving it a light tap with a plastic mallet while energized.

MPDano · MPDano's Garage

Hi Glen, yup tapping it didn't help. I will check for power at the terminals after work today. If the key is on, should I get constant power to the pump? Also, the pump is used from 928 Intl, I think there is a 1 year warranty on it.

MountainShark · 12-03-2008, 06:28 AM

interesting that you have to have key on for pump to run when jumpered, I guess a Euro difference. Yes, you should have power to pump. Check the ground for the pump while you are checking power, sometimes can be a problem.

N2O-SHARK · 12-03-2008, 01:15 PM

BY chance did you put the check valve back in backwards?
Take the pump off again and try jumping the posts from a battery charger, should get her going.

MPDano · MPDano's Garage

Check valve? Where is that located? I only replaced the hose and 2 clamps.

N2O-SHARK · 12-03-2008, 01:40 PM

It's attached to the pump outlet itself. Sounds like you didn't mess with it.

MPDano · MPDano's Garage

Oh ok, pump out. Nope, that would be the hard line part. I just replaced the soft hose from the tank to the fuel pump inlet.

MPDano · MPDano's Garage

Quote:

Originally Posted by MountainShark

interesting that you have to have key on for pump to run when jumpered, I guess a Euro difference. Yes, you should have power to pump. Check the ground for the pump while you are checking power, sometimes can be a problem.

MountainShark, you were right! I was confused since i had my Starter Relay is jumped and not the fuel pump jumped. After jumping the fuel pump a few times, it must have loosened something in the fuel pump as it started buzzing and she started right up. I then took the jumper off and put the relay back in, she started right up again. I am really starting to think Glen was right about the pump, it's flaky. Not sure if I made a good decision on getting a used one. I should have bought new. I can finally start moving forward again this weekend. Yesssssss. Thanks all for your help again

Danglerb · 12-03-2008, 06:20 PM

Pump isn't flaky until it doesn't work with power at the terminals.

Not saying it isn't flakey, just that it isn't proven yet.

Leo, did you check the screen on your fuel tank outlet when you cleaned it?

MPDano · MPDano's Garage

Thats the thing Mike, it did have power to the pump as verified with a check light and the pump was not buzzing. I kept using the spade by unplug/plug a few times before it started buzzing again. This is when it started. The day we were all trying to start the car in October, Glen was using a rubber mallet to get it to buzz. I feel confident that this proves it. And yes, the screen was cleaned squeeky clean. I would never put something back that wasn't absolutely clean, especially when it involves removing the tank again. At least this is my theory anyways.

Danglerb · 12-03-2008, 09:03 PM

928intl will make good on the pump, I just wasn't sure on the testing.

Did you measure 12v, or just a check light?

Across the two terminals on the pump, or one terminal and a chassis ground?

Not worried about clean on the screen, but I have seen them slightly detached which might let junk through. Mine seemed fine while I was cleaning it, but just before putting it back in I noticed the screen was coming loose from the plastic frame.