Did I short out the ECU?

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13bnurse

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So my 88 yj is fuel injected with external fuel pump. I wanted to put the fuel pump in the tank so had to drain the fuel. I thought i would be slick and bypass the relay and make the pump do the work. I jumped the wrong one. Apparently the red wire with white goes to ECU and the one i jumped to was a ground. A spark or two was noticed. With new pump in place now i dont have power to the pump. I have checked wires from relay to pump and all good.
Looking back at what i did do you think i damaged something in the ECU

I guess you cant fix it as it is encased in some glue like rubber stuff

Thanks
 
Can you give more details on the Jeep? Is it a 4.2L with aftermarket Howell throttle body injection kit?
 
I had the Howell kit on one of my CJ's and yes there should be a fuse for the pump somewhere in the system. Might google howells website where full install instructions can be found. Hard to say offhand what/where somebody did during the install you have.
 
machoheadgames said:
Can you give more details on the Jeep? Is it a 4.2L with aftermarket Howell throttle body injection kit?
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I am third owner and have limited history. It is a 4.2 with what appears to be fuel injection of 1991 or later
I have attached photo of the ECU. I have not yet looked up those part numbers to see what year

Reason I pulled the tank to change the fuel pump was couple reasons. Fuel gauge not working, and would run out of gas at a half tank. I found that the old unit in the tank had rusted off
 

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13bnurse said:
I am third owner and have limited history. It is a 4.2 with what appears to be fuel injection of 1991 or later
I have attached photo of the ECU. I have not yet looked up those part numbers to see what year

Reason I pulled the tank to change the fuel pump was couple reasons. Fuel gauge not working, and would run out of gas at a half tank. I found that the old unit in the tank had rusted off
Click to expand...
Okay, that is actually the Mopar MPFI kit. It as you said runs off the fuel injection of the 91-95 4.0L.

Is there a fuse and relay box under the hood? I believe that kit had to add some extra wiring and fuses somewhere.
 
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No fuses or more relays that the two on fire wall…the one I tried to jump and cause this problem. I did buy two relay switches but that did not fix problem.
 
13bnurse said:
No fuses or more relays that the two on fire wall…the one I tried to jump and cause this problem. I did buy two relay switches but that did not fix problem.
Click to expand...
Well it was not the ECU I just tried to swap a different ECU I ordered and still no power I have not found a blown fuse and looked at each of the 8 or so that are under the dash. What am I missing?
 
Did you identify what the relay is for which you initially jumped? Also what slots in the socket did you jump.

You may have a very weak ground or power connection due to corrosion and the brief short opened the circuit somewhere along the wires.

Remove every relay and every fuse, one at a time, and clean each blades and sockets. Even clean every sensor connector you can locate. Electrical contact corrosion is a big factor with these older Jeeps and even if this doesn't solve this problem now, it will prevent future head scratching in the future.
 
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I recently became aware that this was a mopar upgrade fuel injection kit. I am not sure of the two relays I messed with just know that it was bottom middle vertical and top middle horizontal. Red / white wire traced back to ECU and the othe to a ground.

I will give a slow review of each connection point again So frustrating but I see your point
 
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