No Voltage to fuel pump
#1
03-26-2014, 03:09 PM
No Voltage to fuel pump
I am new on this forum. 1992 Mazda B2600i has no voltage to fuel pump. Ran a hot wire to pump and it works. Pulled panel off under drivers side dash and checked relay. Relay tested fine.No power on L/G wire with key on.Does this wire originate from engine control box?What other sensors or relays could be in circuit? Can I just run a wire and switch to fuel pump?
#2
03-27-2014, 03:25 PM
update on fuel pump problem
Pulled passenger side under dash panel to look at ecu. Looked like it had gotten wet. Wiring had a dusty residue coating. Discovered rust hole in floor below ecu. Water and dirt had entered through hole. Removed ecu and opened cover. Some of the components have rust on them. Suspecting this is the cause for no voltage to fuel pump and probably other things. Will need to repair or replace.
#3
03-27-2014, 03:42 PM
Check out http://www.avproecm.com/ . They rebuilt my 1992 b2600i ecu a couple of years ago. Truck runs perfectly.
#4
03-27-2014, 04:18 PM
ECM capacitors are notorious for leaking (older style caps) inside the ECM and usually cause the fuel injectors to malfunction or drivability sputters, typically not fuel pump.
Also there is a relay that goes out that will not let it run. Its possible that it got some water in it at some point. Its not the fuel pump relay, its part of the ignition if I remember correctly. It is on the passenger side by the battery. Give that a check too.
Check out this site it has a lot of info... B2600i.com | Mazda Truck ECMs, Parts, Troubleshooting for B2600i B2600 B2200 B2000. Engine Control Modules, ECM ECU, Brain Box, New & Used Parts, & Repair
Good luck
Also there is a relay that goes out that will not let it run. Its possible that it got some water in it at some point. Its not the fuel pump relay, its part of the ignition if I remember correctly. It is on the passenger side by the battery. Give that a check too.
Check out this site it has a lot of info... B2600i.com | Mazda Truck ECMs, Parts, Troubleshooting for B2600i B2600 B2200 B2000. Engine Control Modules, ECM ECU, Brain Box, New & Used Parts, & Repair
Good luck
#5
03-27-2014, 04:25 PM
See if you can find some info on this PDF of the wiring manual.
https://www.dropbox.com/sh/gqugfum92...wm3/Wiring.pdf
https://www.dropbox.com/sh/gqugfum92...wm3/Wiring.pdf
#6
03-27-2014, 04:45 PM
Also a common problem with these trucks the the ignition switch harness goes bad and looses connection in the "run" position. The plastic part attached to the harness, not the key cylinder part. That might be worth a check too.
Good luck
Good luck
#7
03-27-2014, 05:06 PM
This is from a thread on MT, Follow this and see if it helps.
I got a little curious and went and looked at my 91 b2600i, which according to manual, should be wired like yours. Regardless of what your ignition switch looks like, with the ignition switch set to on/run, it should supply 12V to the "Engine" fuse in the fuse panel (I had mine pulled when I shot this pic.)
From there, it supplied power to the Circuit Opening (Fuel Cut?) Relay via the Black/White stripe wire - as per the manual.
(Ignition On/Run)
So if your fuse is good, and you're not getting power to the relay or to the fuse panel, then it would have to be the ignition switch, or a broken wire somewhere in between.
From there, it supplied power to the Circuit Opening (Fuel Cut?) Relay via the Black/White stripe wire - as per the manual.
(Ignition On/Run)
So if your fuse is good, and you're not getting power to the relay or to the fuse panel, then it would have to be the ignition switch, or a broken wire somewhere in between.
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