No fuel coming into filter

[StinkyCheese]

I have a '73 240z, stock. I finally got it to spark (see http://www.classiczcars.com/forums/showthread.php?t=41386), and now I'm trying to get fuel to it. After a month of trying to get it to spark, I may have run all of the fuel through it. I put 5 gallons in the tank and cranked the engine for a good 2 minutes with no success. The fuel filter is dry.

I looked in my Haynes and Chilton manuals. Each suggest that the '73 didn't have an electrical pump - only the mechanical pump up front. I crawled under and couldn't find an electrical pump, either. At least not an external one. I took a couple of pictures of what I did see, and I'm a little confused.

There are two wires coming out of a module on the tank. I assume these are the fuel-level indicator wires. There are 2 more wires in the bundle that look like they've never been hooked up. (see pictures).

Either way, I'm not getting gas to my motor. There hasn't ever been ANY debris in the fuel filter - I don't think its a clogged line. Assuming my fuel lines are dry and I only have the mechanical pump, do I have to prime it somehow?

Thanks for the help - I'm really a noob when it comes to this, but I'm really enjoying the education. (My wife is trying to talk me into selling it, she doesn't really believe that I enjoy working on it. Would be an easier sell if it was ACTUALLY RUNNING:angry:).

[Powderkeg]

I had a similar problem with my 280Z with 72 SU Carburetors.

My fuel line was clogged. And my Mechanical fuel pump was leaking.

You said you don't think it's a clogged line... are you sure?

Spray starting fluid into the bowls of the carburetors. I just pulled the hose from the top of the carb bowl and sprayed starting fluid through the inlet in both of the carbs. (See photo)

The car started and ran for about a minute.

I then blew out the hard lines from the tank to the fuel pump and carburetors.

The car started on it's own and ran fine until I noticed the fuel pump leaking. Ordered a new one from AutopartsWarehouse.com for $19.95.

The car runs fine (Except for two bad plugs wires..on order).

Sounds like you may have to check your fuel tank for debris.

A recoating of the tank may be in order.

Also do you have a factory service manual? They are easily downloaded from this site.

Good luck.

Dave Ruiz

[clayton 260z]

That would be your sending unit for your fuel gauge.

[StinkyCheese]

I then blew out the hard lines from the tank to the fuel pump and carburetors.

The car started on it's own and ran fine

You blew out the hard lines? Do you know how much gas you had in the tank when you did this? I read somewhere on this site that you have to have your tank 3/4 full for it to "prime" the line. I only have about 5 gallons right now.

When you blew out the lines, how long did it take for the fuel to reach the front of the car? I wonder if there's a way to suck the fuel forward manually. I'd like to KNOW that the fuel isn't caught on a clog before I start tearing things apart..

[StinkyCheese]

Cool, that's what I thought. Any idea what the spare wires are for?

[Arne]

Spare wires are for an electric pump. Even cars that did not come with such a pump had the wires. Ignore 'em.

[StinkyCheese]

Cool, thanks

[Bruce Palmer]

What was the status of the gas in the tank pior to your starting this project? How long sitting?

Take the gas line loose on the inbound side of the fuel pump and see if the pump will pump known good fuel to the carbs. Pull the plugs and just have someone spin the engine over. If things have been sitting a long time this will get oil pressure up in the bearings at the same time without hurting things any more. Then if the pump is pumping you should be able to start the car once you put the plugs back in 'natch.

Then you can start back toward the tank. Probably wouldn't hurt to douche some of that Great Basin alkili dirt off of things while you are under there.....

[StinkyCheese]

There hasn't ever been ANY debris in the fuel filter - I don't think its a clogged line. Assuming my fuel lines are dry and I only have the mechanical pump, do I have to prime it somehow?

So I took the advice and blew some compressed air down both the hard lines. Lo and behold, I took the air off and gas started flowing into my filter. But it still won't start. When I try to start it, you can see the fuel moving inside the filter. The filter is about 1/2 full. When I start cranking you can see the level go down to about 1/4 and you can see "pulses" of fuel going out of the top of the filter toward the pump. (I took a video and tried to attach it, but it wouldn't take. )

Does anyone know if that is the proper behavior for the fuel. Should it be pulsing?

The FSM says to test the pressure coming off the pump while the engine is running "at various speeds". Mine only runs at one speed - starter speed! It says "if the fuel in the carb float chamber has run out and engine has stopped, remove the clip and pour fuel into the carb." Can someone describe where I find this clip?

Edited March 2, 2011 by StinkyCheese

[StinkyCheese]

The car has been sitting since October. It was nearly empty when it died, and I think I used all the fuel trying to get it started while diagnosing the spark problem. I put 5 fresh gallons in it last night.

How will removing the plugs help? I'm confused...

I'm headed to the parts store to get some long fuel lines so I can direct the fuel from the pump into a gas can. The FSM says I should be able to move 1/2 gallon in about a minute. I'm going to try that.

[Bruce Palmer]

Spinning over an engine with dry bearings with the plugs removed will take the strain off of dry bearings until you get oil circulating thru out the engine internals by spinning the engine over which in turn spins the oil pump. I just wasn't sure when some of this stuff was happening.

Okay, now where exactly is this filter you mention? If it's after the fuel pump then it sounds like the pump is working and you can forget all that other stuff I mentioned. If the pump is working you should be able to fill the float bowls with fuel and from there it is all down hill. Gravity etc. etc. etc.

[StinkyCheese]

The filter is before the pump, so the pump is sucking fuel from it. I took off the hose that went from the pump to the hard lines that feed the carbs. I hooked up a 4' piece of hose and directed it into a gas can. The FSM says I should be able to move 1/2 gallon in a minute, but I think it meant at idle speeds... How do you do that??

Anyway, with my daughter running the starter, the pump took a long time before it got fuel to the end of the hose. But when it did, it looked good (I guess). Like Bruce said, I should be able to fill the float bowls with the pump, so instead of trying to open it up, I hooked the hose back up to the carbs and cranked it. In about 15 seconds it started sputtering and a minute later I was revving! Such a sweet sound. That sound really brings a tear to my eye. Plus all the smoke in the garage helped.

So anyway, after 5 months of off-an-on tinkering I took it for a short 2 mile drive. So happy.

Since it appears I DID have a blockage, I think I'm on the path of dropping the fuel tank and getting it boiled out.

THANKS everyone for your suggestions and help! These forums (and you guys) are amazing... Just wish I knew anything so I could give back! Who knows, maybe this thread will help someone lurking around...