Counted Out

iTrader: (6)

So I got the clutch back in (after many, many problems) and I went to start the car and it seemed like it was out of gas. So I put 5 gallons of gas into it and tried to start it up. I turned the key and I could hear the fuel pump priming.

I then started the car and it started for a few seconds then it turned off. I tried to start it again and it just would not start. After looking things over, we realized it wasn't getting fuel anymore. Also, when you turn the key, you can no longer hear the pump priming.

We tested the fuel pump connector and it doesn't seem to be getting any power. Is the fuel pump toast or is the wiring/electronics acting up somewhere?

hawk584

iTrader: (1)

trap door mod. pneumatic sheers, no sparks no risk of cutting fuel lines

RamAir95TA

iTrader: (2)

Likely the fuel pump. Get a gauge on there to verify before you go cutting stuff up.

Cut-off wheels make quick work of the trap door. Don't worry about sparks - there's nothing to ignite.

Counted Out

iTrader: (6)

Well I'm thinking it might be an electrical issue because the fuel pump connector isn't getting power.

I have a lift, so taking the fuel pump out shouldn't be a huge challenge, but I was considering the trap door if the fuel pump is the culprit.

Counted Out

iTrader: (6)

How do you check it? I checked the connector for power, but I'm not sure how else to check it.

Yes, I'm a newb.

RamAir95TA

iTrader: (2)

There isn't supposed to be power at the fuel pump prime connector. It's purpose is to run the pump by jumping a 12v source TO the connector.

Counted Out

iTrader: (6)

How do I check to see if the fuel pump is any good then?

And I checked the fuel pump connecter with the key turned on, if that makes a difference.

RamAir95TA

iTrader: (2)

Maybe I wasn't clear in my first few posts so I'll say it again.

Get a fuel pressure gauge and verify your fuel pressure via the Schrader valve on the fuel rail. Should be somewhere around 43psi with the key on, engine off (41-47 psi is spec). A fuel pressure test gauge is an invaluable tool for any LT1 owner.

Putting a voltmeter on the fuel pump prime connector won't do anything. From my last post - There isn't supposed to be power at the fuel pump prime connector. It's purpose is to run the pump by jumping a 12v source TO the connector. Understand?

Counted Out

iTrader: (6)

That's what I needed to know, thank you.

Counted Out

iTrader: (6)

The PCM seems to be turning off power to the fuel pump relay after a few seconds, is that normal?

93Z2871805

iTrader: (5)

Did you check the pressure at the rail? Did you change the fuel filter? Did you change the relay? Those are the 3 things to do first, and in that order. The relay and filter are cheap enough.

BTW, if you have to change the pump, the trap door is easier than using a lift to drop the exhaust, rear and tank down to change something that only involves 2 quick disconnect lines, 1 vapor return line, 5 nuts, 2 clip-in attachment points on the bucket, and a sock.

Counted Out

iTrader: (6)

I didn't check the pressure at the rail, I know the fuel pump isn't turning on at all so there isn't going to be any pressure. I'll double check it though.

I changed the relay, no change. When I was testing the relay (a new relay) the pink wire seems to be getting power constantly - which it should be. The green wire, which gets hot when the key is turned, is only getting power for a few seconds then turning off.

I haven't tried changing the fuel filter though, I will tomorrow.

jaycenk

iTrader: (1)

If you are just turning the key to run and not starting the key it will only give power for a few seconds as fuel injection systems don't keep fuel pressure at starting pressure all the time. It needs that second or 2 that it takes before you engage the starter to build fuel presure so when the injectors cycle they have fuel to spray. There is a test port really close to the pcm that is a red wire with a singe small conection. This is the by pass feed to power the fuel pump. take a peice of wire and stick it in the test port and then jump it to the batt. This will give constant power and run the fuel pump untill you disconect it. This is what ramair is saying. Before you jump that test port, hook up a fuel pressure tester to the valve on the back of the fuel rail. then jump it and record the reading. If you get nothing then it's going to be either a bad wire(10% chance) or a bad fuel pump (90% chance). If you have fuel pressure report back what you have and some of the guys can tell you weather it is in the range or not.

Counted Out

iTrader: (6)

Thank you. That helped clear things up. I'll try what you said tomorrow.