FlyingDog

The car cranks easily. When the ignition switch is on, the fuel pump runs endlessly. IIRC, it should cut off after a few seconds if the engine isn't started. I can feel the LH and EZF relays clicking on with the ignition switch. The injectors are getting 12V (from the fuel pump relay). I can actually hear the gas running through the fuel rails (never noticed that before). I don't have a noid light or anything like that.

I haven't taken anything apart on the engine other than the headers and the airbox.

AO

Spark?

piccardo

As I understand it, the fuel pump should prime the lines to get them to the required pressure then shuts off and starts again after the engine starts running. If the fuel pressure regulator has failed you might be hearing the fuel running back to the tank thru the return lines to the fuel tank.The injectors will not work if the minimum pressure is not reached.

FlyingDog

I am thinking I'm missing spark and injection. I'm going to double check the EZF relay, since that's one of the ones I had to partially rewire. The other possibility is carnk sensor. Can you damage a crank sensor installing a clutch?

Last time I tried to check for spark on my car I shocked the hell out of myself. What's a safe way to check for spark?

AO

Take a spare plug (if you don't have one pull one of your plugs) stick it in the spark plug boot, then while holding the boot, ground the threds to the block. Crank the engine & watch for spark. If you get a shock doing this, then your wires must be toast.

FlyingDog

Nothing at the plugs, nothing at the coils. I bridged the ezf and LH relays, still nothing.

jyoon

can one person hold the spark to the block and crank the engine? i always had to have help checking spark.

FlyingDog

The LH is not getting power. I don't have 12V at X8. With the LH connector disconnected, the fuel pump relay coil should not have ground. Somehow it is getting ground.

FlyingDog

Correction. I do have voltage at X8. It just isn't making it to the LH at pin 9. The resistance from X8 to LH9 is 5.5Mohms

FlyingDog

Anybody know if the wire colors for an 84 LH connector are the same as an 85 LH connector? 84 wiring diagrams don't have colors on them, but 85s do. I assume they are the same. My LH connector has been PO'd.

FlyingDog

Here is where I'm stuck. The grounds for the fuel pump relay and LH relay coils come from pins 17 and 21 on the LH. The grounds for the LH are 5 and 11 (electronic), and 25 (power) Those seem to be good in the harness. With the LH and fuel pump relays bridged, I still get nothing.

Rich9928p

You'll find the LH and EZF connector diagrams in this post.

I'll explain a little before going to specifics.

a. Fuel Pump

The fuel pump is controlled by the LH, the LH provides the ground path for the fuel pump relay low current (control) circuit for the fuel pump relay. The LH will not turn on fuel injection or the fuel pump until it sees an RPM signal from the EZF (EZF pin 16 to LH pin 1). The LH will only turn on the fuel pump when it sees the RPM is 50 RPM or more - after that the fuel pump will run all the time.

b. No Spark

If there is no spark, it is a good guess that there will be no fuel injection. So you should always fix the spark problem first. The inductive RPM sensor + signal connects to EZF pin 7, and negative to pin 19. The sensor is shielded, and the shield connects to EZF pin 20. The EZF outputs signals to two seperate switchgears (final stage transistors), that are located in the front of the car under the hood, ahead of the radiator. You should confirm that the plugs to the final stage are free of corrosion and that the connection from the EZK connector to the final drive connector is a good circuit. I've provided the schematics for the all the relays and the electronic system. With this information you should be able to check the circuits to see that they're good.

It is a big help to use an oscilloscope, you can verify that the output of the RPM sensor is within spec, that the EZF is outputting signals to the final stage transistors, that the final stage is outputting the signal to the coils, and that the coils are producing spark pulses. If the coils are working, then the only remaining items are the coil wires, distritubors (and distributor belt that drives the secondary rotor), rotors, distributor caps, spark plug wires and the spark plugs.

I suggest starting at the relays, verify that there is battery voltage at the 30 sockets of the LH, EZF and fuel pump relays. Then work all the way to the spark plugs.

Hope this info helps.

FlyingDog

Thank you Rich. I repaired the PO damage in the LH connector. I'm only getting 2.8V at pin 30 of the EZF relay and 2.8V at V3 which feeds the EZF and ABS relays. V4 which feeds the LH and fuel relays is 12.5V. I don't see any points along the wires from the battery to V3 and V4 where I could have caused a break with the work that I did. Can I bridge V3 to V4 or will that cause too much current to go through the wire from the battery to V4?

I'm going to try to probe a few points along the V3 wire through the insulation. I'll also try to clean and reconnect it at the battery.
Edit: 12.5V where the wires turn forward at the quarter panel. 3V at the end of the sheathing by the CE panel.

Rich9928p

Check the connectors at the battery + terminal. They provide the juice to the 30 circuit.

FlyingDog

The 30 circuit is at 12.5V. The V3 wire from the battery up the passenger side of the car to the CE panel is the only thing I can find that isn't correct. The V4 wire that runs right next to it is fine at 12.5V. The problem with the V3 wire is somewhere between the quarterpanel and the passenger footwell. V3 is the thinner of the two.