Fuel pump or relay???
Thread Starter
On The Tree
Joined: Dec 2005
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Fuel pump or relay??? Today I put gas in the tank and decided it was time to check to see if I had any leaks in the fuel system. Turned the key and the pump ran for a few seconds then stopped, everything seemed fine. Checked for leaks and couldn't find any, turned the key again, same thing, no leaks. Turned the key a third time, pump ran and then started clicking, like the relay is kicking on and off about every second. 
I bled the pressure off at the rail and tried it again. As soon as the line is up to pressure the relay or pump is kicking on and off about every second or more
. Is this the relay or the pump that would be causing this problem?
I've got a Walbro 255 in tank pump that I got with my magna charger kit. 1 return line and one supply line going to a corvette filter/regulator and then a single line up to the fuel rail. I don't think it's anything in between because it only does it when it's under pressure.
I bled the pressure off at the rail and tried it again. As soon as the line is up to pressure the relay or pump is kicking on and off about every second or more
. Is this the relay or the pump that would be causing this problem?I've got a Walbro 255 in tank pump that I got with my magna charger kit. 1 return line and one supply line going to a corvette filter/regulator and then a single line up to the fuel rail. I don't think it's anything in between because it only does it when it's under pressure.
well thinking that everything is connected right it sounds like a bad relay or a bad ground for the relay ...it shouldnt click like that make sure the computer harness is grounder right and so is the car and engine
Teching In
Joined: Oct 2004
Posts: 38
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See the last paragraph in post #12, this thread: https://ls1tech.com/forums/conversions-swaps/562845-04-gto-wiring-diagrams-66-nova.html
For potentially useless information. From surfing around some of the vendors and personal web pages you can link to from here it seems like the 97 and 98 PCMs are unique, the 99+ PCMs are evidently interchangeable.
For potentially useless information. From surfing around some of the vendors and personal web pages you can link to from here it seems like the 97 and 98 PCMs are unique, the 99+ PCMs are evidently interchangeable.
TECH Regular
Joined: Jan 2004
Posts: 426
Likes: 4
From: Austin, TX
Are you sure that your pressure regulator is working and returning fuel to the tank? It sounds like your pump is stalling due to excessive pressure. The fact that you said that it runs fine when pressure bleeds off, sure leads in this direction.
Regards, John McGraw
Regards, John McGraw
Thread Starter
On The Tree
Joined: Dec 2005
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After some deliberation and several good suggestions I made another pass at the problem this afternoon. First thing I did was made sure the battery was fully charged, which it was. Then I went back through and checked all of the grounds and still I had the same problem. Then I checked all of the power supply connections, all seemed in good order. So I ran a hot wire straight to the pump to see what happened, and everything worked fine. Now I am convinced (in my head) that it has to be a bad relay.
One thing that bothered me when I was tying my new harness into my old wires was how large the new switched hot wire was. The wire that I had tied it into wasn't nearly that large. I grabbed the smaller wire and it was hot!!! Now it all made sense, running the fuel pump, the pump for the intercooler and everything else was overloading the little wire.
Found a larger wire under the dash and made the connection and guess what??? No more problem. Thank you all for the great suggestions without them I would've spent days tracking this down.
One thing that bothered me when I was tying my new harness into my old wires was how large the new switched hot wire was. The wire that I had tied it into wasn't nearly that large. I grabbed the smaller wire and it was hot!!! Now it all made sense, running the fuel pump, the pump for the intercooler and everything else was overloading the little wire.
Found a larger wire under the dash and made the connection and guess what??? No more problem. Thank you all for the great suggestions without them I would've spent days tracking this down.
