350 TBI and Fuel Pump Issues

Ricky B

Ricky B

Wiiide Open
Joined
Mar 20, 2005
Location
LKN - Tha Dirty Mo (Mooresville, NC)
ok my buddy has a 85 k5 blazer with the 350 and the previous owner swapped TBI onto it. I have two questions kinda dealing with the same thing.

1. The previous owner also wired in a switch to turn the feul pump off and on whenever you want under the dash kinda as a "theft detterent" since the thing isnt very hard to steal, lol. Currently thou its running off the stock harness like normal sothe switch is hooked to nothing. Would using the switch for the feul pump be fine or would having the feul pump run all the time be an issue? (There is a return line to the gas tank for any excess feul)

2. For some reason all of a sudden his fuse for the feul injection keeps blowing which means if it blows on the road . . . . no more engine/power steering/etc so we definitly need to fix that. Other then tracing wiring and trying to hunt down a short, anybody got any other helpful tips?

Thanks
 
1) Fuel pump - id hook it to a relay (like factory) and then use the ECM fuel pump feed to hit the +12 on the relay and then use your theft deterent switch on the ground lead to the relay.. So basically if you leave the deterent switch on it doesnt hurt anything, and off... well it does its job..

2) Trace the wires if it was a swap its really the only way. My guess it you've got a bad poor ground. Many of the ECM outputs are pulled to ground.
Also check the engine block grounds there should be a few heavy ground leads on there, the ecm should ALL ground there, then to the battery
 
And check any splices and/or connections made to the harness. No wire nuts or crimp connectors. Solder and shrink wrap are the only way to go with the computer.
 
on my J10 with a TBI and on my J200 with a TPI I used a fuel pump from a 280z. I have it running all of the time is has plenty of pressure.
 
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