Armycop

Was at Grattan this Labor Day weekend with my old man and our mutual girlfriend..the 'vette! After two days of trouble-free running, pops was on the track turning fast laps when he came into the pits suddenly. "the car won't accelerate!" he shouts. Pop the hood, and the engine is running rough, bucking on the mounts. We check plug lines, none burned, no arcing in the engine bay. Some throttle, and she bogs down hard. Check Engine light starts to flash at me. ****!! I start pulling codes, and P0171(Fuel Trim Sys Lean Bank 1) and P0300 (Engine misfire) catch my attention. I try to start it back up, and nothing. Lots of crank, no fire. All the plugs are sparking, so I have the lighter. I couldn't hear the fuel pump cycle because of the noise at the track, so I crawl under the left tire and have pops turn the key to 'run' so I can listen for the fuel pump. I get an audible 'click' but no pump whine.

So now we're home, ole' girl's in the garage, and just to make sure it isn't a relay, I switch out the fuel pump and horn relays. Still hear the 'click' (relay is good) but no pump whine. Time for a new fuel pump? And while I'm down there, what about the other tank? is that a fuel pump too, or just a filter? Your input is appreciated!

lucky131969

A quick fuel pressure evaluation at the rail will tell volumes. Also, you can pull the fuel pump relay, and use a jumper(of proper size) across the relay socket contacts...sending power continuously to the pump. Of course you want to make sure you have power and ground to the pump connector itself.

LoneStarFRC

Sounds like good advice. Fuel pressure gauge hookup is easy too.

BTW, the fuel pump is in the driver's tank, so if you have a bad pump that's where you go. The pump in the passenger side is non-electrical.

dgrant3830

Checking the ground for the fuel pump is a good idea. Also check the ground wires on the rear of the driver's side head...make sure they didn't come loose.

Armycop

Grounds are good all round, checked them this morning. I still hear a nice loud 'click' right at the fuel pump, driver's side tank. Anybody have a write-up on the garage guy's method of replacing the fuel pump? Y'know, on yer back and using jackstands?

lucky131969

So did you jumper the contact on the relay socket and listen for the fuel pump running? If you can't hear the pump, did you check to make sure you have 12 volts at the fuel pump connector?

Just trying to make sure you have a bad pump before you go tearing apart the car.

Armycop

Sorry, i'm a doofus. I did check for voltage at the pump; it's 12.06v. That's good, right?

MySR71

Sorry to hear about your trouble. I was there with the silver Z06 parked under the tree.

Armycop

Well hi there! Shouldn't you be working today? Did you ever track down that whistling noise?

lucky131969

Yep. So provided you have 12 volts(which you do) and a good ground at the pump connector (and the contacts/wiring at the pump connector are good) then the pump is the culprit.

lucky131969

I can email you the service manual procedure. PM me your email address.

runamuk

1. Raise car
2. remove left rear tire
3. disconnect lines and electrical connector at the pump
4. slowly remove some of the lower bolts securing the pump and be prepared to catch all of the fuel left in the tank.
5. remove the pump.

Armycop

I'm not keen on #4. It usually ends up on me, mostly.

runamuk

Thats what really sucks about the fuel pump not working at all, there is really no way to get a hose into the filler opening to suck the fuel out since there's a check valve in the opening to protect the car in case of a rollover, it would have to be a very small hose, so your only other option is to just drain slooowwwllly.

BLOWNBLUEZ06

Here's some instructions
http://www.lingenfelter.com/pdf/c5fu...structions.pdf

When draining the tank, just loosen all the 8mm bolts and then use a ratchet on the bottom one to control the drain speed. You can even put your hand on the pump to control the outflow. It's not a big deal.

Fastguy

Sorry to hear you guys had trouble with the car. It sounds pretty good here.

LMB 4 ME

Armycop

Good morning George! I see you made it home okay. Nice clip we had going there. They sound alike, don't they? Thanks for the vid.

Fastguy

2 hours back to Ken's, stayed over, and then 13 hours back. I have a bunch of short clips like that I can send you that are better quality than youtube. Is it definitely the fuel pump?

Anthony01

The way we test them at work is using a headlight. One of those old sealed ones. Anyway unplug your sending unit and hook the HL to the 12v and ground of the sender, Grey and Black wire. Cycles the key and crank for a sec. or 2. If the headlight comes on, then you know your whole circuit is good and theft deterrent is not interfering.

Junk sending unit