Fuel Gauge Craziness

TerryG · 10-04-2009, 10:27 AM

My aunt has a 2000 Jimmy that's been having starting problems. After a dead battery they jumped it and the fuel gauge needle now points towards the floor board. It sat in their garage for a few weeks unable to start and then the other day it started up but the gauge is still all jacked up. Any ideas? I was thinking fuel pump or they fried something when they jumped it.

Thanks
Terry

cpolaris502 · 10-04-2009, 01:23 PM

It's hard to say if it just started happening after they jumped it, but with these trucks it is very common for the sending unit to go bad and cause the gas gauge not to work. but with how you described when it happened, its hard to say it is the pump.

TerryG · 10-04-2009, 01:38 PM

I was thinking fuel pump when they first started having the starting issues. We put a new filter on it and it seemed to help for a bit but it was only a temp fix. The filter was pretty nasty when we pulled it off so I was thinking the strainer was prob full of crap then they jumped it and all hell broke loose.

There is pressure at the check valve on the fuel rail, and the pump does run when the key is turned on, but I don't have a fuel pressure gauge to check just how much pressure there is. Since the pump and sender are only available as a complete assembly I was thinking/hoping the problems were related and the fact that it happened after the jump was just a coincidence.

Thanks for the reply.
Terry

Edit: I was just told that it had done it a few times before the jump start but lined out after a few fill ups. Sounding more and more like a pump/sender to me. Any thoughts?

TerryG · 10-04-2009, 01:54 PM

Ok, little more info. They've been driving it for the past week or so and it starts and runs fine unless it sits more than a day.

cpolaris502 · 10-04-2009, 02:30 PM

Ok, thats a good sign then. i dont want to tell you the fuel pump will fix the gauge though but it is a good chance, it could be anything.

On the starting issue... try turnign the key on before starting it so that the fuel pump primes. My bravada is acting the same way right now, not starting right away after it sits for a while. if i let the pump prime before I crank it it starts right away. But if i just hop in and try to start it, it takes about 5 seconds of cranking before it will go. I put in a new fuel pressure regulator last week after seeing that that was a common problem but it didnt fix the issue for me. My next thing to try is either the spider injector or fuel pump, but my gas gauge is also screwed up so i might put in a fuel pump anyway and hope that it fixes both of my problems.

if you can get a hold of a pressure gauge, let us know the results.

TerryG · 10-04-2009, 02:46 PM

If they decide on a pump I'm doing a new filter and pressure regulator just for kicks. I really hope it's not the spider, those bastards are expensive even with my discount. Plus, I've been told they're rather involved, and I really don't want to get into all that.

Will let you know the pressure situation when I get to check it.

cpolaris502 · 10-04-2009, 07:55 PM

The regulator is just as involved as the spider. The regualtor mounts in it. And as far as i know, when I was chasing a fuel issue in my blazer 2 months ago, the spider and pump are about the same price, you're lucky you get a discount though.

And heres some pictures of when I did the regulator in my bravada last week.

I took the injector out, the FPR is right on the back of it.

10-04-2009, 10:27 AM	#1
TerryG Hater Join Date: Feb 2003 Posts: 22 Location: Perryville, MO User is: OffLine	Fuel Gauge Craziness My aunt has a 2000 Jimmy that's been having starting problems. After a dead battery they jumped it and the fuel gauge needle now points towards the floor board. It sat in their garage for a few weeks unable to start and then the other day it started up but the gauge is still all jacked up. Any ideas? I was thinking fuel pump or they fried something when they jumped it. Thanks Terry
	[Reply w/Quote]

10-04-2009, 01:23 PM	#2
cpolaris502 The Dreamsicle Age: 20 Join Date: Jul 2005 Posts: 16,052 Location: Rogers, MN User is: OffLine	Re: Fuel Gauge Craziness It's hard to say if it just started happening after they jumped it, but with these trucks it is very common for the sending unit to go bad and cause the gas gauge not to work. but with how you described when it happened, its hard to say it is the pump.
	[Reply w/Quote]

10-04-2009, 01:38 PM	#3
TerryG Hater Join Date: Feb 2003 Posts: 22 Location: Perryville, MO User is: OffLine	Re: Fuel Gauge Craziness I was thinking fuel pump when they first started having the starting issues. We put a new filter on it and it seemed to help for a bit but it was only a temp fix. The filter was pretty nasty when we pulled it off so I was thinking the strainer was prob full of crap then they jumped it and all hell broke loose. There is pressure at the check valve on the fuel rail, and the pump does run when the key is turned on, but I don't have a fuel pressure gauge to check just how much pressure there is. Since the pump and sender are only available as a complete assembly I was thinking/hoping the problems were related and the fact that it happened after the jump was just a coincidence. Thanks for the reply. Terry Edit: I was just told that it had done it a few times before the jump start but lined out after a few fill ups. Sounding more and more like a pump/sender to me. Any thoughts? Last edited by TerryG : 10-04-2009 at 01:39 PM.
	[Reply w/Quote]

10-04-2009, 01:54 PM	#4
TerryG Hater Join Date: Feb 2003 Posts: 22 Location: Perryville, MO User is: OffLine	Re: Fuel Gauge Craziness Ok, little more info. They've been driving it for the past week or so and it starts and runs fine unless it sits more than a day.
	[Reply w/Quote]

10-04-2009, 02:30 PM	#5
cpolaris502 The Dreamsicle Age: 20 Join Date: Jul 2005 Posts: 16,052 Location: Rogers, MN User is: OffLine	Re: Fuel Gauge Craziness Ok, thats a good sign then. i dont want to tell you the fuel pump will fix the gauge though but it is a good chance, it could be anything. On the starting issue... try turnign the key on before starting it so that the fuel pump primes. My bravada is acting the same way right now, not starting right away after it sits for a while. if i let the pump prime before I crank it it starts right away. But if i just hop in and try to start it, it takes about 5 seconds of cranking before it will go. I put in a new fuel pressure regulator last week after seeing that that was a common problem but it didnt fix the issue for me. My next thing to try is either the spider injector or fuel pump, but my gas gauge is also screwed up so i might put in a fuel pump anyway and hope that it fixes both of my problems. if you can get a hold of a pressure gauge, let us know the results.
	[Reply w/Quote]

10-04-2009, 02:46 PM	#6
TerryG Hater Join Date: Feb 2003 Posts: 22 Location: Perryville, MO User is: OffLine	Re: Fuel Gauge Craziness If they decide on a pump I'm doing a new filter and pressure regulator just for kicks. I really hope it's not the spider, those bastards are expensive even with my discount. Plus, I've been told they're rather involved, and I really don't want to get into all that. Will let you know the pressure situation when I get to check it.
	[Reply w/Quote]

10-04-2009, 07:55 PM	#7
cpolaris502 The Dreamsicle Age: 20 Join Date: Jul 2005 Posts: 16,052 Location: Rogers, MN User is: OffLine	Re: Fuel Gauge Craziness The regulator is just as involved as the spider. The regualtor mounts in it. And as far as i know, when I was chasing a fuel issue in my blazer 2 months ago, the spider and pump are about the same price, you're lucky you get a discount though. And heres some pictures of when I did the regulator in my bravada last week. I took the injector out, the FPR is right on the back of it.
	[Reply w/Quote]