- - Fuel sending unit
01-18-2014 07:06 PM
Fuel sending unit
Quick question about switching out my sending unit. Everything I read online says to stall the vehicle by removing the fuse to the pump to drain the lines of fuel when you remove it. Well since GW have an awesome access panel to the pump without having to drop the take can I just disconnect the wiring while it is running to bleed the lines so I don't spill any fuel?
Thanks for any help. I plan on starting my own thread for all my planned improvements/tinkering later with pics to help other nubs like me.
01-18-2014 07:16 PM
The unit and the wagoneer
01-18-2014 07:29 PM
If you disconnect the incoming line to the fuel pump, it should drain back to the tank. There really won't be much fuel stored in the lines either way though. Are you replacing the rubber lines while your in there.
01-18-2014 07:54 PM
I hadn't planned on it yet. I don't have any hose. The fuel gauge doesn't register and I wanted to decrease my chances of running out of gas. I thought about doing that later and maybe replacing the tank too.
01-21-2014 10:32 AM
So I got my new sending unit from team grand wagoneer. I decided to test it first. All the connections connect well for my 88 GW. But it didn't solve my problem. The fuel gauge still doesn't move at all. Any suggestions?
01-21-2014 10:39 AM
Check power to the FSU. Multitester, or test light
01-21-2014 11:42 AM
I checked it before and I was getting ~12V. Need to check it again I apparently. It's snowing and I've got a big exam Friday. Guess it will have to wait. I was hoping it would be a "simple" fix. I'm guessing either the ground or the gauge, which they don't sell online for an 88 from what I've seen.
01-21-2014 12:59 PM
Very well could be ground, either at the FSU, or at the gauge. Do you have a meter?
01-21-2014 01:15 PM
I think one of my roommates has one at the house. I usually borrow them at the DIY garages I go to on base.
01-21-2014 09:18 PM
Originally Posted by jamesmega
Quick question about switching out my sending unit. Everything I read online says to stall the vehicle by removing the fuse to the pump to drain the lines of fuel when you remove it.
Not sure what you're talking about. You should have a mechanical fuel pump, not an electric one.
01-23-2014 07:36 PM
What I had watched online must have been from GMs with electric pumps. Regardless the gauge doesn't read testing with the new sending unit. I'll try getting to the gauge to clean connections this weekend to see if that's the issue.
01-31-2014 03:58 PM
So this is where I'm at with trying to get to the fuel gauge. That's about all the wiggle room I have. There are two bundles of wires one round and one flat and the cable to the speedometer. I'm getting voltage to the FSU and have tried multiple grounds with the new unit but no change in the gauge.
Does anyone know what the next steps are to remove the cluster? I'm thinking this maybe way above my PMCS skill level.
01-31-2014 04:28 PM
So I got that round connector off a little and the connections look pretty clean. Continuing to chase my white whale.
01-31-2014 04:33 PM
Another question, I ordered new fuel lines. Do I need to drop the tank or raise the wagoneer to replace? I can use a lift on base at the auto skills center if needed or if it makes it easier. Thanks for the input.
01-31-2014 08:27 PM
You can get some slack for the speedo cable under the hood, enough to disconnect at the cluster. Determine which pin is going to the gauge, and check for power. The gauge cluster grounds to the dash frame, make sure your ground connection is good.