Fuel Pump

For discussing injector selection, manifold modifications, throttle bodies, fuel supply system design and construction, and FIdle valves and IACs.
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BooBoo
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Posts: 20
Joined: Sun Aug 22, 2004 5:16 pm

Fuel Pump

Post by BooBoo »

My fuel Pump went up in smoke yesterday (literally). I replaced it with a new pump today. The problem now is that when I am not getting any power to the fuel pump. The stimulator fuel pump LED lights up when the MS is connected. I replaced the fuse and relay on the relay board with no help. I have to assume that something is damaged the relay board. Any idea what could have gone wrong? This fuel pump and relay board have been working for many years.

I have a MS V2.2 with a MSII.
BooBoo
MegaSquirt Newbie
Posts: 20
Joined: Sun Aug 22, 2004 5:16 pm

Post by BooBoo »

I checked the voltage with the fuel pump relay removed (the center relay - K2). These voltage numbers I got directly off the relay board.

30 and 86 have 12v when the ignition is on and the engine is not running.
87 is a ground
87a is nothing
85 has aprox 0.1v when the ignition is on and the engine is not running
85 has aprox 1.0v when the engine is cranking.

I am not an electrical engineer so I don't know if this is right or not. Can someone let me know if they are right or what they should be.
BooBoo
MegaSquirt Newbie
Posts: 20
Joined: Sun Aug 22, 2004 5:16 pm

Post by BooBoo »

Any chance the problem is one of the Raychem Polyfuses?
BooBoo
MegaSquirt Newbie
Posts: 20
Joined: Sun Aug 22, 2004 5:16 pm

Post by BooBoo »

I did some more testing and found that. I made a mistke earlier, I do not get a ground on 87. When the fuel pump is supposed to run I get a ground on 85. 86 and 30 are +12v when the key is on. I get +12v across 85 and 86 when the fuel pump is supposed to be running. That seems to me like it should work. When I take a ground wire and connect it to to the back of the relay board on the post for 85 the fuel pump runs. Is it possible that the ground coming from the MS is not strong enough?
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