Fuel pump issue?

M

Mudeprived

New member
I recently ran out of gas again (4th time) and started to notice a slight rough idle on start up in the mornings or after it has sat for a few hours. It would act like it is missing for abt 10 seconds or so and then idle normally with no odd behavior while driving. This morning it started the same way but the rough idle would not stop. It would shake a little then smooth out when I press the accelerator. It was fine once I started driving.

It reminds me of the heat soak issue I had with my old 2001 cherokee.

Does this sound like a fuel pump issue or something else?

99 Limited
171k
 
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well on a GM truck it you run out of gas 3X then the pump is cooked..

never run the truck with less than 1/4 tank or it is a hard job to fix and if you have a tech to replace it very expensive job . low fuel with alcohol in gas is another issue as more air in tank more water in tank then the corrosion of the complete fuel system..

new vehicles do not have fuel filters external mounted so the intank filter will get plugged up due to alcohol creating organic growth with low fuel in tank.

good luck ,
 
catrains said:
well on a GM truck it you run out of gas 3X then the pump is cooked..

never run the truck with less than 1/4 tank or it is a hard job to fix and if you have a tech to replace it very expensive job . low fuel with alcohol in gas is another issue as more air in tank more water in tank then the corrosion of the complete fuel system..

new vehicles do not have fuel filters external mounted so the intank filter will get plugged up due to alcohol creating organic growth with low fuel in tank.

good luck ,
Click to expand...

I have not had much luck with this truck. I bought it and ran out of gas cuz the gauge was not working and I was not told abt it by the PO. So I had to figure out the mileage to follow and ran out in the process of determining how far I can go. I been following mileage till last winter when I lost 70 miles to the tank (winter gas maybe?) and ran out ahead of the usual mileage. Then suddenly the gauge starts working this past fall and I followed that till last week when it ran out with a 1/4 left. I forgot that i used the truck as a generator when the power went out and burned alot of fuel and the gauge pooped out again at the same time. I usually fill at 270-280 but ran out at 220.

I never ran out of gas in any of my vehicles since I started driving at 15.....till I got this truck.
 
Rough idle on start up could be a bunch of different things (injectors, coils, MAF, even a bad head gasket).

Are you loosing any coolant?

You should be able to check your fuel pressure. "FSM says 38-44 psi with ignition on, 33-38 psi at idle, and 38-44 psi with the vacuum sensing hose to the regulator disconnected. For the 5vze anyway"

And get your fuel gauge fixed so you don't have to guess anymore....
 
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thegipper said:
Rough idle on start up could be a bunch of different things (injectors, coils, MAF, even a bad head gasket).

Are you loosing any coolant?

You should be able to check your fuel pressure. "FSM says 38-44 psi with ignition on, 33-38 psi at idle, and 38-44 psi with the vacuum sensing hose to the regulator disconnected. For the 5vze anyway"

And get your fuel gauge fixed so you don't have to guess anymore....
Click to expand...

Not losing coolant.

I will clean the MAF again since it gave me issues before. I will also check the fuel pressure and report back with any findings.

I assume I need to drop the tank to fix the fuel gauge sensor? I doubt the actual gauge itself is bad.
 
doing 280 miles if your using 18MPG then you may only have 3 gallons in it ...

IMO your probably getting 15MPG'S so that may explain the damage due to consistent low fuel ..
 
catrains said:
doing 280 miles if your using 18MPG then you may only have 3 gallons in it ...

IMO your probably getting 15MPG'S so that may explain the damage due to consistent low fuel ..
Click to expand...

I average 16-17 during summer and 14-15 in winter.

My tank seems to only hold 16.5 gallons. I stuck two gallons in when I ran out, drove 1/2 mile to gas station, and could only fit 14.6 gallons. I had it on the slowest fill setting.
 
Mudeprived said:
I average 16-17 during summer and 14-15 in winter.

My tank seems to only hold 16.5 gallons. I stuck two gallons in when I ran out, drove 1/2 mile to gas station, and could only fit 14.6 gallons. I had it on the slowest fill setting.
Click to expand...

1999 only has 16 gallon tank ... do not go 280 miles ...

280 miles you will have an empty fuel tank . use about 16 gallons..
 
Mudeprived said:
Not losing coolant.

I will clean the MAF again since it gave me issues before. I will also check the fuel pressure and report back with any findings.

I assume I need to drop the tank to fix the fuel gauge sensor? I doubt the actual gauge itself is bad.
Click to expand...

Yes, the sender gauge is in the tank. There's a TSB (Toyota Service Bulletin) about a faulty sender gauge that also includes repairing the gauge cluster in the dash that includes 99's. You might have one of those affected vehicles, it's a very small list though.

If you do end up replacing the pump, looking into replacing the engine sender assembly as well. It's simple enough to do on paper, but dropping the tank can be a major pain based on how stuck the vacuum hoses and fuel lines are.

Mudeprived said:
Nope. Seems simple enough to do so i will get one on order.
Click to expand...

Just be sure to use a brake line or crow's foot wrench on the compression nuts. If you use a standard open box wrench the nuts will strip, then you'll never get the old fuel filter off.
 
catrains said:
1999 only has 16 gallon tank ... do not go 280 miles ...

280 miles you will have an empty fuel tank . use about 16 gallons..
Click to expand...

Interesting. I was told I had a 18.5 gallon tank. What years had the 16?

I once went 307 miles before I got gas. It was a long stretch of no gas Ohio and luckily made it. That is why I always assumed I had the 18.5 gallon tank.
 
Mudeprived said:
Interesting. I was told I had a 18.5 gallon tank. What years had the 16?

I once went 307 miles before I got gas. It was a long stretch of no gas Ohio and luckily made it. That is why I always assumed I had the 18.5 gallon tank.
Click to expand...

All 3rd gens have the 18.5 gallon tank. If you have anything other than that, it was not original to the vehicle.
 
catrains said:
1999 only has 16 gallon tank ... do not go 280 miles ...

280 miles you will have an empty fuel tank . use about 16 gallons..
Click to expand...

Not exactly accurate

The tank is 18.5 gallons. The vent tube inside the tank is "too long" and prevents filling past 16.5 gallons easily; this is a known "issue" that most of us live with although some have modified/shortened the vent tube about 1"

I have "overfilled" my 99's tank many times, topping off slowly, and have gotten 325 miles out of a single tank. I know I do so at the risk of flooding the evap system and ruining the charcoal filter, but that's the risk I decided to take. I am not recommending anyone do this, but 280 isn't bad, depending on how you drive and over what terrain with what load.

It is very common to fill up at E and only get 12.5 gallons in. The upside of this is you won't run out of gas.
 
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Looks like there is no way to test fuel pressure on this truck unless i get a special fitting?

This truck gives me a headache. I am starting to miss my Jeeps.
 
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Mudeprived said:
Looks like there is no way to test fuel pressure on this truck unless i get a special fitting?

This truck gives me a headache. I am starting to miss my Jeeps.
Click to expand...

I know, its annoying but Toyota isn't the only one that does this (Honda does it also, I'm sure there are others).

This should be what you need depending on the fuel pressure gauge you have. Come to think of it, I need one!

https://www.amazon.com/Russell-6407...000CPJI8I/ref=cm_cr_arp_d_product_top?ie=UTF8
 
thegipper said:
I know, its annoying but Toyota isn't the only one that does this (Honda does it also, I'm sure there are others).

This should be what you need depending on the fuel pressure gauge you have. Come to think of it, I need one!

https://www.amazon.com/Russell-6407...000CPJI8I/ref=cm_cr_arp_d_product_top?ie=UTF8
Click to expand...

Is there another piece I should have? I have a screw on type fuel pressure tester. My jeeps' had a valve on the rail that I screwed it onto. It did not come with any other adapters.
 
I haven't used my fuel pressure tester recently either so I cannot remember if mine has a threaded end or if it uses the 1/8" NPT port.

My guess is you need this adapter instead or similar to it but accommodates whatever end is on your fuel pressure gauge. Essentially a banjo bolt with those metric threads and the other end matches your fuel pressure gauge. Many of fuel pressure gauge kits come with adapters, just not the goofy banjo bolt style ones.

https://www.ebay.com/itm/GlowShift-...dapter-M12-x-1-25-to-1-8-27-NPT-/292038719073
 
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