Fuel Pump test 350 Vortec

[uglyota]

Drove the chevy around all yesterday afternoon. Parked it in the driveway, worked on the Yota for a while, tried to start the chevy and it wouldn't fire. Turns over great (actually pretty fast, but I'll get to that) but doesn't even try to start. When i was working on the yota, I had a piece of sheetmetal in the bed of the chevy, using it as a welding table, but always had the ground attached to the piece that I was working.

When I put the key in and turn it to "on", I don't hear the fuel pump whine. When I'm turning it over, I don't hear it whine (gas cap off, ear to tank). Now that I think about it, it seems like the pump was whining particularly loudly in the last few weeks. I also have known several people to have to replace fuel pumps on 350s around 125k. My truck has 127,000 on it.

My first thought (hope...I put 22 gallons in just the other day) was fuses. They are all fine in cab and underhood. Next thought was the fuel pump relay. Turner came over with a Tahoe and we swapped in his relay--to no avail.

Is there any other test for the fuel pump without actually pulling it? The Yota has a connector that you can short out to force power to the fuel pump. Is there anything like that on this truck?

Also, after turning it over like 10 or 12 times, there is no gas smell in the engine compartment.

My only other guess is the timing chain. It seems to turn over really fast, but I don't think I've ever heard of a tchain going out on a 350 at 127k, and the truck really hasn't been abused, maintained meticulously, etc. Maybe it's just my hella-strong battery (I gaht Optimah!). That wouldn't explain the fuel pump, though. Does the top end of the engine have anything to do with the fuel pump circuits? Is the Vortec an interference motor?

I haven't checked for spark. I should probably do that.
The only thing that throws me off is that it drove fine all afternoon and then wouldn't start, which makes it so much harder to diagnose:(

If it ends up being the fuel pump, does anybody have a spare lying around? Suggestions on where to get a good one? Is this a Carter, and do the parts stores stock them, or do I have to go bend over for Sterling Chevy? Aftermarket upgrades and where to get them?
Thanks in advance
Eric
324-0670

[Doug Krebs]

Are you sure you didn't fry your computer some how by welding in the bed? I've weld plenty of times on my truck, but some people say that it can fry your computer.

I'd look at the fuses first. Then check the computer.

[jerryg79]

i've got that code reader if you wanna borrow it....not sure how much it would do though, it will show anything the computer throws out though. Maybe there is some code for fuel pump failure?

[uglyota]

Doug: the fuses are all good (underhood and in-cab).
Snatch: are you in town or K-vegas? Does the code reader work without the truck running? Wanna come by this afternoon?:cheers:
402 Francis Dr. Behind the Chili's on University.

[jerryg79]

The one i have you have to have computer for, since i dont have a laptop (my gf does) i had to move my computer outside you'll have to load some software but its easy ****....that being said all it needs is the key in the on position and it will do the rest.

Anyway, I'm leaving town in about an hour or two got some errands to run, give me a call on the cell if you still want it 713-857-7150.

Oh and mike yes i do have a cellphone:rainbow:

[uglyota]

No laptop, and I really can't leave work right now, especially since I've pissed away my first 2 1/2 hours. But thanks mang. Maybe julio with the twice pipes will bring a handheld unit down for me:D

[uglyota]

well, 3am this morning I finally got the new fuel pump in. Learned a few lessons here. Change your fuel filter early and often. I don't know if mine had ever been changed...I sure didn't do it. Somehow when I was trying to catch up on all the maintenance that had never been done in its first 80,000 miles, tranny filter and fluid came to mind, but never fuel filter. The pump probably wore itself out trying to push fuel through the scum. Hopefully I'll gain some economy with this, too. Second...if you have to change the fuel pump on a late model chevy 350 you have a few options. Option 1, do it yourself...alone...in the dark. Plan on burning up 6 bulbs in your "suicide light" since I'm too cheap to buy one with protection. Plan on breathing lots of fumes and getting gas all over yourself, being very sore the next day from being in weird positions and bench-pressing a full gas tank (pumps never go out on an empty tank, and if they do, the first thing anybody does to try and fix it is to put a fresh tank of gas in). Oh yeah, I also probably said more swear words than I have in the last two months last night, so chalk up an eternity in hell as one of the costs of this option. Option 2, If it's not going to send you careening into debt, get a tub of vaseline and something to bite on, call Sterling GMC, and give them what they want. This is probably less painful than my method. Option 3, buy two cases of beer, call 4 big friends, and pull the 6 bed mounting bolts and the hose clamps on the gas tank. Have the friends pick up bed, move it back a few feet, and set it back down. They drink beer while you replace pump and filter without bumping your head and/or cursing in pain. Do this fast so they will be sober enough to help you put it back on. Slide bed into position, put bolts back in, drink the rest of the beer.
Just thought I'd leave a little legacy for people who actually search.:cheers:

[jerryg79]

the "check engine" light came on in my truck when the fuel filter was clogged, that and it pinged like a mofo at high rpm.

[uglyota]

Drove it to school.
Feels good, but no different than before the problem. Don't think my fuel filter was clogged. 2 people? Shiiiit...my toolbox alone would take 2 people!
She'll be pulling the blue beauty on trips from now on!

[jerryg79]

Is your fuel pump still loud? Mine has always been extremely whiney!

[AgDieseler]

Is that a charactaristic of Chevy in tank pumps. I drove around my uncle's 02 Tahoe for a while (he also has a pocket knife), and damn that sucker screamed. I could hear it inside the truck with the windows up.

[robertf03]

thats how you know they are working

Fred's scout whines like a little bitch. good diagnostic tool for efi conversions

[uglyota]

the original always had that high-pitched whine, but this one (a carter) is more of a hiss. The whine got a lot louder in the last few weeks. Same thing happened when the yota pump went out...got real loud for a few weeks and died. Snatch, I'd do anything possible to keep yours alive (don't run the tank till its empty, replace filter). My pump was like $150, but after 97 you have to replace the entire sending unit, getting you up around $500.