occhevelle

Just tried to start my 67 Chevelle with 04 GTO LS1 and it won't turn. Do I need to prime the fuel system? If so, how? Is there an easy way to see if the engine is getting fuel? Thanks!

chuckd71

iTrader: (23)

Going to need a lot more info than 'it won't turn' I'm afraid. I primed my fuel lines by turning the key a few times. A fuel pressure gauge on the rails would be the easiest way to see what's going on, or you could always disconnect something and check.

occhevelle

I'm having a tough time describing it but the starter goes and no bang. It sounds like when you're out of gas which is why I think it is that. I'm just test firing it so the dash and gauges aren't in yet. I disconnected the fuel line at the fuel rail and it looked dry so I think I think the pump may not be working. I'm using a 95 impala with the walbro pump. I grounded the black wire from the tank, gray to 12v, and did not hook up the gage wire. Would that cause a problem? I think I'm just going to pull the pump assembly and see what's happening. BTW I don't have the throttle cable hooked up - do I need to open the throttle body a little to get it going?

Rikoshay

If there isn't fuel at the rails then you need to find out why.

chuckd71

iTrader: (23)

Yeah, throttle wouldn't prevent fuel being in the rails. Do you hear your pump priming?

BanditDave

iTrader: (11)

You need to make sure where you tapped into for power to the pump is 12V in the start and run position. It would have to be a switched Ignition 12V.

We can start there.

Also, how is your fuel system plumbed - i.e. from the pump it goes to a filter? a filter regulator? what? Gas should spit out of the line pretty quickly once you turn the key. My guess is it is not wired in correctly at this point.

The devil is in the details....we LOVE details my friend.

Dave

stealth71

iTrader: (15)

A walbro 255 will make some noise when it's running. If you turn the key forward it should turn on for about 5 seconds making an audible hum. If you don't hear anything then it's probably wired wrong.

On the pump isn't there ground, 12v power, pump signal and fuel level? Should be 4 wires IIRC. You need 12v power to the power and pump signal wires or hook the signal wire to the PCM. Also what size wire are you running for power to the pump and do you have a fuse inline?

bczee

iTrader: (12)

Are you saying that you connected the pump/sender directly with out a relay and just jumping the Ground and Battery 12V terminal of pumps/sender hot and ground terminals?

If you did that and didn't hear the pump you might have bad pump or the wires inside the tanks sender are incorrectly connected or not connected.

If you hear the pump and using a Vette FPR, check to make sure you have the lines correct, that being the Feed, Return and output (to fuel rail). if you switch the Feed and Return, you will not get any fuel to the output and fuel rail.

And as Chucdk71 stated. You should not have to open the Throttle for it to start.. If any FI car/setup. you normally would not open/step on the throttle to start anyway, unless you put it into the Flood mode to start.

occhevelle

Thanks for everyone's responses. As for my system, I plumbed it based off of bczee's setup. I don't hear a hum so I'm assuming it's the wiring. I'm using the 95 impala gas tank stock wires (black, gray, purple). I made the assumption that the old fuel pump power wire was good. I'm gonna pull the pump and go through the whole wiring setup tonight. I did wire the power directly without a relay. Do I need one?

bczee

iTrader: (12)

I would highly recommend using a relay.. the PCM activation term would not be able to handle the amp load (30amp) of the pump. Wire the power side of the relay directly to the Battery or the Alternator.

Relay pins (IIRC, but do a search on wiring the relay for the fuel pump):
Term 85 = PCM Red #9 to activate the relay (Can be fused)
Term 86 = Ground
Term 30 = +12v Battery/Alternator (fused 30amp)
Term 87 = To hot side of Pump (some well fuse it ?)

stealth71

iTrader: (15)

Where are you getting 12v power from?

You need a ~10ga wire coming from the battery or alternator. Fuse that and run it to the relay. Hook the relay up as shown above.

Here is what the racetronix hotwire harness looks like. Make something similar:

bczee

iTrader: (12)

+1 on the Racetronix kit. I am using the kits.. great setup.

If your not good with wiring, i would suggest one, pretty much plug-n-play. Order the Bulk head opioin along with it.

Project GatTagO

iTrader: (7)

Definitely need a relay.

Andrew

occhevelle

I know you guys are saying I need a relay, but are there problems that could arise from not using one? I found that the power wire was bad and now have the pump running on key turn. Before I order the racetronix setup, is this okay or do I need the relay setup? Am I asking for problems?

Project GatTagO

iTrader: (7)

Yes, you need a relay. The fuel pump may run at idle when powered by the wire from the ECU, but as soon as the pump sees load the fuse for that circuit in the ECU will blow. That wire was never designed to carry the load of a pump, which is probably close to 20amp. It is only designed as a signal wire to the relay to turn the pump on or off, as required.

I always have my battery mounted in the trunk on all my builds. That way I can run short power wires to the pump through the relay and have maximum voltage at all times. Fuel pumps need 12-14 volts to be happy.

Andrew

bczee

iTrader: (12)

+1 on a Relay usage .. ! There is an writeup on the Racetronix site about Voltage and Pump performance (yeah, its also a marketing thing to sell there kits, but point is well taken).

http://www.racetronix.biz/itemdesc.a...%2D004&eq=&Tp=

Project GatTagO

iTrader: (7)

$50 for that kit is not too bad. I've never used a kit, but that's mostly because I didn't need the extra long power wire, since my battery was in the trunk.

I learned to wire the fuel pump this way the hard way. When I first built my GTO it had a fuel injected 502 big block chevy. I was using the old Holley Commander 950 EFI system. Their instructions were a little vague so I wired the fuel pump without a relay. The pump would run and the car would start. I'd get it out of my driveway and a little way down the street, tap the gas and the engine would just shut off. The fuse in the fuel pump activation circuit would blow. It was only a 5 amp fuse which was enough to power the pump without load, but as soon as I got on the gas: pop!

Once I installed the relay is was perfect. I had almost 14volts to the pump, which is what the alternator puts out. Since then, the engine has changes, the EFI system has changed, but the same relay and fuel pump wiring are being used with my LSx engine.

Andrew

occhevelle

Thanks for the advice guys. After all my whining, I actually wired in the relay and I think it's good. When I turned the key to prime the line, the pump turns on for a couple seconds and then off. Is that right? The reason I ask is it still no starty...

chuckd71

iTrader: (23)

It should be noticeable initially as it rebuilds pressure and then not so much, at least that's how mine works.

occhevelle

http://s29.photobucket.com/albums/c2...IMG_2782-1.mp4

This is a quick video I took of the trunk/top of the fuel tank. Any ideas what I'm screwing up?