Won't start, no fuel at injectors ?

[cary]

Good Evening,

I'm in the process of getting my new 73 driver up and running.
73, 1.7 L.

Car ran great before R & R of engine. I replaced a most vacuum and fuel lines. Changed the plugs. Hosed her down with Simply Green and cleaned her up. Replumbed the fuel lines from the firewall to the engine. Shes sat for almost a week, so it should be dry.

Now she won't start. I've got spark. She starts great with a shot of starter fluid. Pulled the plugs, dry as a bone. All I can smell is ether.

Fuel pump seems fine. Runs for 1.5 seconds ( primes ) with ignition turned on. With ignition in the crank mode, pump runs.

At the pressure regulator I seem to have pressure. But only air. When I loosened the supply hose. I get a burst of air and a little gas. When I run the ignition in the crank mode fuel begins to flow.

I checked the plug on the side of the distributor, looks good.

Where do I go from here ?
It ran fine before the R & R of the engine.

[Ron Meier]

Maybe, just maybe, you crossed the fuel lines at the pump.

S - suction (from the tank)
D - pressure (Druck) to the first fuel rail - cross to the second rail - second rail to the pressure regulator
R? - return - from the non-pressure side of the regulator - teed at the pump with the line returning to the tank

And

check for a plugged/kinked suction line or filter.

And

check for electrical polarity at the pump - I thought I followed the Haynes manual and my pump was running bassackwards.

[cary]

Thanks Ron, for the reply.

Double checked the hoses they are right. Looked for a squished hose, its ok.

The polarity issue. With the factory plug how could it be reversed ?

Thats the odd part. I unhooked the D line from the pump. When I turn on the ignition, nothing comes out the tube. The pump runs for its 1.5 seconds. But to me, it seems it should load up the fuel system to the regulator. Shouldn't fuel be flowing during the priming ?

[cary]

More info ................. The connector for the fuel pump had the ground wire broken off. So the only ground was thru the body.

But the odd deal. The car will get fuel and run, if I clamp off the fuel return line, back to the tank. So it seems I have pressure going back up the return side to the injectors. But not regulated.

So we'll see what happens when I get the wires fixed.

Shouldn't the return line be a draw to the pump. Not pressure. Right ?

[Dave at Pelican Parts]

Yes, fuel should flow during that 1.5 second "priming". Check for a kinked fuel line. Most especially, check for one under the fuel tank.

The plug can get reversed if you pop the wires and contacts out of the plastic plug body. And then you realize that Haynes shows you a nice diagram, but doesn't tell you if it's the connections on the pump itself, or looking at the plastic plug from the pump side (or from the wire side for that matter). And those are opposites... BTDT!!

I don't understand your last question about a "draw"...

The idea is that the pump pushes the fuel into the high-pressure loop. The regulator blocks the fuel until it gets to a high enough pressure, then it bleeds off some of that pressure. That is how 29 PSI is maintained.

--DD

[cary]

Orginally posted by Dave at Pelican Parts
The idea is that the pump pushes the fuel into the high-pressure loop. The regulator blocks the fuel until it gets to a high enough pressure, then it bleeds off some of that pressure. That is how 29 PSI is maintained.

--DD

B I N G O

I was looking at the loop backwards. Thinking that the fuel went to the regulator, first. Then it maintains it from there. Opps..

I would have done all 3 engines, wrong.

Switched the lines at the engine split. Fired right up. Thanks..

I don't understand your last question about a "draw"...--DD

How does the return work ? Does it have a suction pressure back to the pump ? Then what kind of pressure returns excess fuel to the tank ?

[cary]

Originally posted by cary
Double checked the hoses, they are right.

Not Exactly. Thanks Ron.

Took a good wack from a 2 * 4 to get me to see it straight.

Dave and Ron thanks for the help. We'll be on the road soon.
$1k 914 and one 20 year old garden tractor cart for donated steel.

We've got her all patched up. Stiffened her up pretty good. No flex at the door, putting a 200 # person in the seat.
It was a mess. We've learned a lot. Which will help when we tear into the 74 2.0L we originally bought for my sons first car.

Ron I'm about ready to use the engine case I bought from you.

[Dave at Pelican Parts]

Originally posted by cary
How does the return work ? Does it have a suction pressure back to the pump ? Then what kind of pressure returns excess fuel to the tank ?

The return is simply a spring-loaded valve. When the fuel pressure gets high enough to overcome the spring force, the valve is pushed open until the overpressure is bled off. Then the valve closes.

The 70-74 pump has a similar valve on it, but this one opens up at a much higher pressure--something north of 50 PSI, I think? This keeps from blowing something if there is a blockage in the line.

Both of these join together at the "Y" fitting near the pump. The third leg of the "Y" runs back into the fuel tank.

--DD

[Ron Meier]

Good Luck - hope some dollars actually get to spend time in your pocket.

I'm off to llok/buy another -14 - Is there a cure for this besides having no money?

[Jared at Pelican Parts]

ron, I have to say i love the new avatar..

ARRGH tis fitting, matey!

[cary]

It's a cureless disease.

[Dave at Pelican Parts]

Actually, I met a guy who was working on a cure a few years back.

They'll never find his body!!! Mua-ha-ha-ha!!!

--DD