Fuel pump?

[Stelth]

Driving home last night, my van (2001 GMC Savana 4.3 v6) started losing power about 100 miles from home. I got off the freeway, and pondered what to do. Realizing that I've never changed the fuel filter on this van, I limped over to a Pep Boys and got a fuel filter. After replacing it in Pep Boys parking lot, the van ran a lot better. I almost made it home. About 10 miles out, it started sputtering, and backfiring through the intake. It would idle fine, and I could drive it at very low speed, but I was on the freeway, so no chance of limping home. I got a tow, and when I got home, I was able to drive it into the driveway.

Since I'm showing the signs of fuel starvation, I'm thinking the fuel pump is dying?

 

[crazyoildude]

check the fuel pressure

 

[Brybo86]

did the CEL come on?

 

[UNC017]

Originally Posted By: crazyoildude
check the fuel pressure


+1

Proper diagnosis >> guessing over the internet based on symptoms. I think its highly likely you'll find a bad fuel pump, but do the correct testing first. You may have to run the engine long enough to get the pump up to operating temperature before the pressure starts to drop.

 

[The_Eric]

Originally Posted By: 440Magnum
Originally Posted By: crazyoildude
check the fuel pressure


+1

Proper diagnosis >> guessing over the internet based on symptoms. I think its highly likely you'll find a bad fuel pump, but do the correct testing first. You may have to run the engine long enough to get the pump up to operating temperature before the pressure starts to drop.



Agreed.

 

[strat81]

Originally Posted By: 440Magnum
You may have to run the engine long enough to get the pump up to operating temperature before the pressure starts to drop.


That's an important point. When the fuel pump in my Buick Rainier died, it acted fine when the pump was cold. It also acted fine when I had more than a half tank of gasoline since the fuel acts as a coolant.

 

[dailydriver]

Originally Posted By: Brybo86
did the CEL come on?


Usually, a dying fuel pump throws no codes.

 

[The_Eric]

Originally Posted By: strat81

That's an important point. When the fuel pump in my Buick Rainier died, it acted fine when the pump was cold. It also acted fine when I had more than a half tank of gasoline since the fuel acts as a coolant.


I though that was a qualifier for a pump going bad. Jeeze, it seems like most of the bad pumps I've replaced have been in a fuel tank with more than half a tank of fuel... That makes it a bit of a pain when you have to man handle them to get them down.

 

[strat81]

Originally Posted By: The_Eric
Originally Posted By: strat81

That's an important point. When the fuel pump in my Buick Rainier died, it acted fine when the pump was cold. It also acted fine when I had more than a half tank of gasoline since the fuel acts as a coolant.


I though that was a qualifier for a pump going bad. Jeeze, it seems like most of the bad pumps I've replaced have been in a fuel tank with more than half a tank of fuel... That makes it a bit of a pain when you have to man handle them to get them down.


LOL, yeah, I helped a friend change the fuel pump in his Expedition that had a full tank (as in, just came from the gas station full). Disconnected the filler neck so we could run a siphon into the tank to drain it. What a pain that was.

Oh, and then there was the other friend whose pump in his Astro died in February, so we got to change that outside in the freezing cold. And then it started snowing. :|

 

[bullwinkle]

I had to change one on my old Voyager in a parking lot, in the middle of summer, after siphoning 3/4 tank of gas out, remember it was 85+. Wish it HAD been snowing!

 

[Shannow]

My L67 Caprice has been entertaining...

History...been a slow starter, requiring a fir bit of cranking since I got it. Chneged the idle air controller, and seemed to improve it....still a slow starter.

Better half rang one day a few months ago to say that the car wouldn't start at the shops. I hopped in and it started. Got home and pulled codes for Crank sensor (got one of them, just can't get the balancer bolt off...still got to work on that.

Car can sometimes be hard to start, sometimes won't. Occasionally died hitting a bump, hard cornering.

Transmission playing up, car snatchy doing strange up/down changes/lock-up...pricing a 4L60E gave me a coronary nearly.

Every now and then I'd floor it to feel the 10 psi boost, as it kicked the rear out...then wouldn't change into third, holding revs and dropping power at 120km/hr, and not revving higher...workmate who's a Holden nut diagnosed knock sensor issues...transmission would really bang into next gear when I backed off.

Changed the fuel pump on the weekend (in tank, turbine two speed thing), and the car is like rand new. Starts quickly, transmission woes are gone, and it sails through 120km/hr, to shift when it should.

I was expecting if it was the fuel pump, it would be a little more directly evident.

 

[strat81]

Shannow's post reminds me... if you get a fuel pressure gauge tool, get a long hose for it. The shorty 2' hose will work fine if you have the hood open and you're standing next to the vehicle. The longer hoses work great for taping the tool to the windshield. Then, you can drive around and have a friend monitor the gauge while the vehicle misbehaves.

 

[Shannow]

Yeah, that's a good idea, should get me one of them.

My old fuel pressure gauge is for vacuum/mechanical pumps, not anything modern.

 

[Stelth]

Replaced the fuel pump in my van. I decided to cut a hole in the floor of the van to make an access instead of dropping the tank. Not sure if that was really the smart thing to do, but it's done now. The tanks on these vans are enormous.