86 B2 electrical/fuel pump issues?

[jkufen]

Well I went to a buddies house last night to help get his old Toyota running and after about 3 hours there I tried to leave and my b2 wouldn't crank. It just keep spinning and spinning. Well I am very familiar with a bad fuel pump as this is my 3rd. I towed it home and got underneath it today. I pulled the pump out and hot wired it to the battery. The pump came on just fine. I then put my volt meter on the power connections to the fuel pump and nothing. The relay is brand new and just had the new plug wired in by my mechanic. The relay clicks when I turn the key. So I am guessing that the issue is electrical between the relay and the high pressure pump. Any ideas where to start looking? I mean I tried to run the wires back from the pump but I only got about a foot before it hit the main cluster and I lost it. Need suggestions please. I got to get her running ASAP!

 

[RonD]

In the passenger foot well or kick panel there is the inertia switch, this is designed to turn off power to the fuel pump if there is a sudden stop, i.e. accident.
The power for the fuel pump runs from the relay to this inertia switch and then to the fuel pump.
So I would check for voltage there, on the IN(relay) wire and the OUT(fuel pump) wire.
There is a reset button on the top of the inertia switch.

The ground wire for the fuel pump is usually located near the inertia switch as well so check any ground wires near by.

And just to confirm, you know there is only power to the fuel pump for 1 or 2 seconds after key is first turned on, after that there is no 12v until key is cycled off and on again.

There is also a 30amp fuel pump fuse(in power box), relay would still click if this fuse was blown, but relay wouldn't have any power to pass to the pump

 

[jkufen]

Sorry I didn't update this earlier but the rear fuel pump is working. When I turn the key on it will pump the gas up and out of the line at the high pressure pump. Now can anyone explain that???!

 

[jkufen]

The ground wire for the fuel pump is usually located near the inertia switch as well so check any ground wires near by.

Are the two pumps grounded separately? That could be my issue if they are.

 

[RonD]

Not sure if they are grounded separately, I would think the in-tank sender and pump, and high pressure pump would all be grounded at the same place.
Easy enough to test with an ohm meter, or test light if you have 12v handy.

The Pink/black wire that comes from the inertia switch runs to the high pressure pump AND to the in-tank pump, so both should be on when key is first turned on.
If you don't have 12v at the high pressure pump then run a new wire to the inertia switch, and splice it in.

 

[jkufen]

The way it is looking I am just going to run new wiring from the inertia switch to the pumps because my truck is so dirty underneath it seems almost impossible to follow the cluster.

 

[johnsongang]

inertia relay switch

I was having some of the same symptoms mentioned above. The switch did not seem tripped, so I disconnected the plug and cranked the engine for about 10 secs, plugged it back in and wala! Everything was fine, Now I have a brake fluid loss, onto the next issue!

Adam

 

[jkufen]

Which plug did you disconnect? The inertia switch? If you disconnected the inertia switch how did you get your truck to run?

 

[adsm08]

The HP pump grounds out at the frame right near the pump. The LP pump grounds near the tank.

There is also a splice near the HP pump where the two powers split. It is possible for the splice to come apart inside and keep power going to one pump but kill the other.

 

[jkufen]

adsm08 that is exactly what I was thinking I haven't really got down there and pulled the wires out but I was gonna take the wires back to where they split from the main harness and see if there is power there. I mean there has to be to power the rear pump. I am hoping to get under it tonight after work or maybe tomorrow morning before work and see what the issue is.

 

[jkufen]

Well the b2 is running once again. All i did was pull the relay out and put it back in. Not sure what it was but the bronco is on the road again.

 

[RonD]

Nice

 

[jkufen]

Now if I can just get my pesky blower motor to work in my ranger I will deem this a successful week!

 

[rusty7983]

When I 1st bought mine, I had a similar problem. After hitting the key numerous times the high pressure pump came on. It was replaced and is now used as a transfer pump. you know drain the tank to change a pump. It has a dead spot. Maybe yours is the same way.