Hi All,

I've searched and read the pinned topic, and just wanted to make sure our diagnosis is correct before we drop the tank.

The fuel pump runs with the ignition on, but we get zero pressure at the service port and zero pressure at the fuel filter outlet.

We replaced the fuel filter, and still zero pressure at both ports.

The car has over 200k miles.

Fuel pump needs to be replaced, correct?

Could it be anything else?

Thanks in advance...

 

The plumbing from the pump could have failed causing the fuel to be sprayed around inside the pump assembly, however, the tank will still need to come down. Zero pressure at the new filter is the reason. Delco and delphi pump assemblies have proven to be the most reliable for our trucks. If you've been off roading, examine all the steel line from the filter to the tank to be sure it's not pinched shut.

 

Thanks for the reply, Rusty.

This work is being done on the 2000 RWD 2dr in my signature, not the Zr2, so no off-road.

We dropped the tank... I did check the lines to the filter, they're good.

Question -

Is it possible to check the new pump when it is dry (out of the tank)?

Reason I ask is because we hooked up the old pump to the electrical connectors when out of the tank and it no longer runs with the ignition on.

Tried the new one and it doesn't run either.

However, the good news is that the fuel gauge works with the new pump (the old pump sender unit was bad as well).

In short, I was wondering if there was a way to test the new pump when hooked up to the wire connectors, yet outside of the tank.

I'm thinking there is a sensor inside the pump that won't allow power unless gas is in the pump? So it won't burn out?

I'd hate to get it all strapped up with a half tank of gas and find I received a defective pump.

 

If you bought a delco or delphi, install it with confidence. I put a new delphi in my jimmy last summer. The upgrade connector was already on it but was tied in with crimp connectors. I removed all that and soldered in the new connector that came with the pump.

 

We're doing the Amazon cheapo fix pump. 43 bucks. After all, the car has over 200k.

Although I did solder in the new connector.

With that said, going by your reply, there is no way to test the pump when dry? (out of tank)

??

 

I wouldn't risk burning up a brand new pump by hot wiring it dry. Are you positive you want a pump that you already don't trust?

 

Well, for the price... I actually trust it better than the old pump. The rheostat moves the Gas gauge on the new pump (I think it's a rheostat... could be wrong...)

So, I guess we're gonna strap it up... rain forecasted tomorrow though.

I'll keep ya posted.

Thanks again for your help...

 

Make sure you have power at the electrical connector at the fuel tank. In the fuse panel there is a fuel pump terminal that you can apply +12V to that bypasses the fuel pump relay.
If you do not have a volt meter to check for voltage, try applying power to the old pump directly from the battery to see if the old pump runs first, then you can use it to check for power at the fuel tank connector.

The fuel pump in my '02 has failed, but not completely as I used it to pump out the tank. Took about 20 minutes to fill a 5 gal container, but at least I do not have to drop a full tank down.

Good luck.

 

Thanks for your reply Lanny.

Well, we strapped it all up and it doesn't work.

Before strapping it up, I checked the voltage at the pump -

The 4-wire connector:
Black = 0V
Purple = 0V
Gray = 12.1V
Black/White stripe = 0V


The 2 Wire connector -
0V both wires


The fuel gauge works. We put a half tank of gas in, the pump is silent when bypassing the relay (pin 30 - 87), and with relay installed. We can hear the relay clicking, but the pump is silent.

Any ideas?

 

Update -

The reason the pump(s) didn't run when out-of-tank was due to a grounding problem.

For those who may find this thread/post in a future search, yes, the pump will run when dry, with the proper power and ground.

I will provide a synopsis when we are done. Hopefully this weekend.