74 1.8 L-Jet No Run - Help Please!, No fuel out of injectors Options

[SteveL]

74 1.8 with L-Jet
- Gas in tank
- Key on and AFM flap moved with screwdriver, I can hear the pump run.
- Removed fuel injector and placed in jar. Key on, moved AFM flap (can hear pump running), no fuel. Reconnected AFM to air intake and cranked it over (can't hear pump over starter), still no fuel in jar. Propped the AFM flap open, key on (can hear pump running), cranked it over, still no fuel in jar.

Best I can figure, I think it must be one of the following:
- plugged fuel filter?
- fuel pump spinning, but not actually pumping fuel?
- fuel pressure regulator?
- injectors not receiving signal to spray?

(IMG:style_emoticons/default/WTF.gif)

Any suggestions?

Thanks

[SteveL]

One thing to add -
It is running an old Pertronix Ignitor. It has been in there for a very long time with no issues. I'm not sure if a failure would cause the no fuel issue (does it send a signal to the injectors?)

[jcd914]

I'm not an L-jet expert or guru but ...

I would check the double relay to see if the Fuel Injection control module is getting power, thing the fuel pump is a separate circuit in the double relay.

I would also check to see if the Fuel Injection control module is getting the signal from the ignition points (white wire to the coil) since the FI won't try to operate the injectors unless it see the ignition signal.

Jim

[JeffBowlsby]

All wires on the resistor pack intact?

[914Mike]

Make sure your double relay is plugged in tight, and then check the ground on the resistor pack next to it. Sometimes the wires in the resistor will break loose from a resistor, or from the common ground on the other end. Either way, no ground, no fuel.

Hey Jeff, doubling up on ya while typing slow...

[lsintampa]

Do you know if the injectors are firing?

My injectors got "plugged" and I needed to free them up.

Get a 9 volt battery, remove an injector and "tap" the contacts with leads from the 9 volt battery to make sure they are firing.

Should hear a click.

Don't hold the charge on the injector - just tap it to power.

I made a test harness from an old injector connector to test.

If they are not clicking, they are stuck. It took a bit of work to get mine working. No point in going into those details unless your's are stuck.

[rhodyguy]

do you have a 'noid' light to check for signal to the injectors? pump running, signal to injectors, no fuel…try filter (easiest). have you ever cleaned or inspected the tank or replaced the output tube screen/sock? is this a out of the blue development or a sometimes it does and sometimes it doesn't?

[SteveL]

do you have a 'noid' light to check for signal to the injectors? pump running, signal to injectors, no fuel…try filter (easiest). have you ever cleaned or inspected the tank or replaced the output tube screen/sock? is this a out of the blue development or a sometimes it does and sometimes it doesn't?

This is the first time it has failed to start. However, this summer when I go to start it I had to crank for a few seconds for the fuel to get there before it would start, rather than firing instantly. I seems like the fuel was back-draining when shut off.

[timothy_nd28]

Sounds like the dual relay is working as it should. Do you have spark?

[Dave_Darling]

Is the white wire from the injection plugged into the (-) terminal on the coil? That's what tells the injection when to open the injectors on an L-jet car.

--DD

[SteveL]

Is the white wire from the injection plugged into the (-) terminal on the coil? That's what tells the injection when to open the injectors on an L-jet car.

--DD

Yep. Wire looks good, good connection.

[SteveL]

UPDATE - Still No Run:
- Have spark
- Key on, push on AFM flap and can hear pump run
- Clean Fuel Filter
- Disconnect fuel hose at Fuel Pressure Regulator and activate pump, fuel comes out, but I don't think fast enough for what the pressure should be.
- Injectors are squirting, but as above, I don't think enough. Tiny little squirt, not a find mist spray.

When it died (on the freeway on-ramp of course) it was acting like it was out of gas.

So, I suppose the next step would be to get a fuel pressure gauge, right??
Where and how do I hook it up?

Thanks All!

[SteveL]

Bump -
Anyone?

[Cap'n Krusty]

First of all, the injectors won't spray when you move the flap. You have to touch the white wire from the point side of the coil to ground to get a pair of injectors to fire.

If it stalled as you were driving, odds are you've lost an electrical connection or a ground for the relay. Losing the CHT sensor connection will do it, too, or the CHT sensor being loose in the head. That's common on Bus engines where the CHT sensor is right out in the open. Or the Pertronix unit could have puked, something that's pretty common, IME. PM me with a GOOD e-mail address and I'll send you an L-jet guide. It's a big file, BTW.

Good luck! The Cap'n

[cwpeden]

Look down the fuel filler with a light see if you find this?

My 73 2.0L acted like it was out of gas too.

Old vs. new



This is where you'll find it.

[SteveL]

First of all, the injectors won't spray when you move the flap. You have to touch the white wire from the point side of the coil to ground to get a pair of injectors to fire.

If it stalled as you were driving, odds are you've lost an electrical connection or a ground for the relay. Losing the CHT sensor connection will do it, too, or the CHT sensor being loose in the head. That's common on Bus engines where the CHT sensor is right out in the open. Or the Pertronix unit could have puked, something that's pretty common, IME. PM me with a GOOD e-mail address and I'll send you an L-jet guide. It's a big file, BTW.

Good luck! The Cap'n

I could get it to almost restart if I pumped the heck out of the gas pedal and cranked, it would fire and sputter for a second before dying again.
Would it still be electrical?

[SteveL]

Update:
I checked all vacuum lines, tested the AAR and head temp sensor (ohm test).
Verified the oil filler is sealed, and checked all the electrical connections. Everything looks good.

I turned the key on and manually moved the AFM flap to engage the fuel pump. I still have the clear fuel lines in the engine compartment. As I hit the flap, I could see gas coming up a little bit in the clear supply line, but it did not flow (there was air uphill in the fuel line). The level only rose an inch or so, not all the way to the rubber hose. There was no fuel flowing in the return line.

For a test, I bypassed the Fuel Pressure Regulator with the fuel line, and engaged the fuel pump again. I could see fuel making the entire loop through the return to tank line, and heard a mass of air bubbles getting pushed back into the fuel tank.

I removed the Fuel Pressure Regulator. I cannot blow through it at all in either direction. Do I have a bad Fuel Pressure Regulator?
Or, is it just that I cannot blow hard enough to open the valve inside? If that is the case, then neither can the fuel pump, and the fuel pump is bad, right??

Thanks