No Fuel Pressure at Fuel Rail ? (1 Viewer)

[MisipLC]

Okee Dokee, we are stumped. Pulled the engine and have re-installed. Plugged everything back and now have a problem getting fuel to the rail.

Using the FSM, checked resistance in the Fuel Pump resistor - good.
Checked the Fuel Pump Relay - Good.
Jumped the fuel fuel pump and it ran. It pumped fuel to the fuel tank side of the fuel filter.

When engine turns, it will fire when spray starting fluid. We got fire.

We are now stumped.

No fuel to the cylinders.

Oh, the check engine light comes on when we turn on the key. So, we have ground wires connected.

Any help will be appreciated.

 

[baldilocks]

I assume you have disconnected the fuel return line and saw no fuel flow from the regulator?

 

[MisipLC]

Correct.

 

[Wayne]

If you have fuel pressure passed the regulator and to the rail, the injectors are next in line. It sounds electrical to me.

 

[Hornd]

Side Note: but check your Wiring Harness at back RH Side of Valve Cover and ensure wires are not charred where harness passes by EGR pipe. Checking takes about 1 minute.
If they are repair, and wrap with heat tape ($20) at Autozone

 

[MisipLC]

Will check the wiring harness for charing. How do I check the injector plugs for power?

 

[MisipLC]

There is no damage to the harness.

 

[george_tlc]

If you have no fuel injection going on:

Check for +12V going to the injectors (+12V is common to all 6 injectors). +12V is present with key to on. The ECU will sequentially fire individual injectors by providing a momentary ground to each one (6 wires from ECU, one to each injector).

+12V comes through EFI relay and fuse etc. Might be something as simple as a blown fuse, you have checked all fuses yes (not just visually)?

cheers,
george.

 

[MisipLC]

So I disconnected the fuel line at the firewall side of the rail. Ran the fuel pump and got gas. I then re-tightened the fuel line and disconnected the return line under the manifold. Ran the fuel pump - Nothing. So I removed the fuel pressure regulator and there was fuel in the rail.

Is there a way to test the fuel pressure regulator to see if it is functioning properly?

 

[MisipLC]

Since I am here, will test the power to the injectors as you suggested goerge.

 

[inkpot]

If you have fuel in the rail up to the regulator, find a bolt/plug
( 12m x 1.25 ) IIRC, to close up the rail and try to start it. If it runs the buy a new regulator. John

 

[MisipLC]

We Check voltage between terminal FC of ECM connector and body ground.Voltage should be 9 − 14 V.

No voltage. It appears the ECM is not sending signal out to the FC.

Thanks for the tip on test the FPR inkpot. Will try that.

 

[inkpot]

We Check voltage between terminal FC of ECM connector and body ground.Voltage should be 9 − 14 V.

No voltage. It appears the ECM is not sending signal out to the FC.

Thanks for the tip on test the FPR inkpot. Will try that.

If the injectors are clicking and there is any pressure behind the fuel you are seeing up in the rail, it should run. Maybe not well, but run.

 

[george_tlc]

We Check voltage between terminal FC of ECM connector and body ground.Voltage should be 9 − 14 V.

No voltage. It appears the ECM is not sending signal out to the FC.

Thanks for the tip on test the FPR inkpot. Will try that.

The ECM does NOT send 12V to FC, it provides a GND going signal to energize the Circuit Opening Relay. +12V for the Circuit Opening Relay comes via a fusible link, then the Ignition switch and finally through the IGN fuse.

With IGN to on but engine not running there will be +12V on both sides of the coil since the ECM will not have switched GND on the FC pin. With engine running (i.e. crank/start/run) the FC pin will drive to GND to energize the Circuit Opening Relay.

You will be chasing your own tail if you don't interpret/understand the ignition/ecm system, it is somewhat complicated versus old school points/distributor/coil

I asked before, have you checked ALL fuses electrically (with a meter)?

cheers,
george.

 

[MisipLC]

Have not. Guess that next step.

 

[MisipLC]

All fuses good. Rechecked the grounds. Replaced the circuit opening relay. Rechecked all connections on the starter. It turned over, then did not. The CEL blinks a couple of times and the starter will not turn over. When it did turn over, it would not start. Checked the coil for spark. It is good. Checked the fuel pump relay and resistor. They are ok. Nothing else to check.