Running rich, fuel pump constantly runs

[Cethern]

SteveJ I thought you had found the missing link.

The 75 is just a little bit different than the 77 my condenser is mounted next to the coil, I just made a jumper with a bullet connector and a eyelet, which is probably why I didn't use the black and blue wire to begin with.

I wish I had a second set of hands to hold the key in the start position to check the voltage on that black and blue wire, but it should be the right one.

[Zed Head]

I've had a weak ignition module before. Showed spark but wouldn't start the engine without starting fluid. It was GM HEI module though.

It would probably help you out to measure voltage to the module and to the coil, with the key On and at Start. Just to verify that the components are getting power when they should. then you can worry about if they're using the power as they should.

As for using the power correctly, the ZX distributors use a circular magnet that is easily and often cracked. Have you had the ZX distributor apart to confirm that the parts are good?

[SteveJ]

SteveJ I thought you had found the missing link.

The 75 is just a little bit different than the 77 my condenser is mounted next to the coil, I just made a jumper with a bullet connector and a eyelet, which is probably why I didn't use the black and blue wire to begin with.

I wish I had a second set of hands to hold the key in the start position to check the voltage on that black and blue wire, but it should be the right one.

As long as the black/blue wire isn't running to the condenser, it's the correct wire.

By the way, it's nice to have a set of leads for your meter, such as clip leads, so you can clip them to the wire and position the meter so you can see it while you're in the car. Of course, if you see the condenser in the engine bay, you could always just do a continuity check between it and the black/blue wire near the ballast resistor, provided there is a wire on the ballast resistor.

[SteveJ]

As for using the power correctly, the ZX distributors use a circular magnet that is easily and often cracked. Have you had the ZX distributor apart to confirm that the parts are good?

Good idea. I used a rebuilt distributor when I did the conversion in the 73, so I never would have thought of that.

[Cethern]

I checked the voltage with it in the key in the run position, I don't have a helper at the moment. I was getting it to run on gas that I got into the intake, at that time I had left off the blue wire for because I wasn't getting any spark with it hooked up.

As far as I can tell it's hooked up as it is on Blue's setup.

[Zed Head]

I checked the voltage with it in the key in the run position, I don't have a helper at the moment. I was getting it to run on gas that I got into the intake, at that time I had left off the blue wire for because I wasn't getting any spark with it hooked up.

As far as I can tell it's hooked up as it is on Blue's setup.

The blue wire feeds the ignition module, the tachometer and the ECU. It branches off to each one, not serial, so disconnecting the module won't hurt the other two. That might explain why it ran with starting fluid, the ECU wasn't opening the injectors. The module controls the coil grounding, and the tach and ECU "watch" what's happening. That's an important wire.

I haven't looked at Blue's page, but I know that the advice there doesn't cover every detail for every model. Usually there's a note about the exact car that was used as an example and the fact that your results may vary. You're probably in to it deep enough now that you could open up the Engine Fuel and the Electrical chapters of the FSM and feel comfortable.

[Cethern]

Zed Head, I checked the voltage at the red and green wires in the dizzy but I didn't pull anything else apart, the cap and rotor look good, but are used (the local parts place didn't have a new one)

SteveJ I agree clip leads would be handy,

I'll take some pictures when I get home from work tomorrow.

[Cethern]

Believe it or not, but I've spent a lot of time reading both of them. One day I'll have to get a good wiring diag with more detail.

I thought I was on the right track with replacing the dizzy, after it ran, but now I'm back where I started from.

[SteveJ]

I checked the voltage with it in the key in the run position, I don't have a helper at the moment. I was getting it to run on gas that I got into the intake, at that time I had left off the blue wire for because I wasn't getting any spark with it hooked up.

As far as I can tell it's hooked up as it is on Blue's setup.

You left off the blue wire or the black/blue wire? The blue wire is critical for the negative side of the circuit. The black/blue wire is critical on the positive side of the circuit during starting.

[Zed Head]

Zed Head, I checked the voltage at the red and green wires in the dizzy but I didn't pull anything else apart, the cap and rotor look good, but are used (the local parts place didn't have a new one)

SteveJ I agree clip leads would be handy,

I'll take some pictures when I get home from work tomorrow.

The red and green only have voltage when the distributor turns and then it goes +-+-+-+... to trigger the module. The standard test is to measure resistance across green and red, looks like about 400 ohms resistance is right. Page EL-30 in the 1981 FSM shows how to measure voltage with the key turned to Start, maybe that's what you did. The coil, both posts, should have power with the key on and during Start. You do need a good ground through the distributor to get things to work right since the module is now mounted there and grounds the coil through the distributor body, which is what generates the big spark. Weak ground weak spark. Usually the bolts are enough but it's easy to check to be sure.

Much fun. Makes you realize the distributor does lot more than just distribute.

[Cethern]

I didn't have a ground wire at the distributor originally, so to get the ZX to work I ran a ground wire from the adapter bolt to a screw on the module. At first I was leaving the blue wire off to just make sure the ZX worked, but when I went to hook it up, I was getting like a strange feedback of sorts, it was sparking without the motor turning over, which could of been because I hadn't disconnected the module inside the car. I have since disconnected the module from inside the car.

Since I know the ZX dizzy will work alone, but not with the ecm, or maybe it will and something else is interfering is what I need to find.

[SteveJ]

I didn't have a ground wire at the distributor originally, so to get the ZX to work I ran a ground wire from the adapter bolt to a screw on the module. At first I was leaving the blue wire off to just make sure the ZX worked, but when I went to hook it up, I was getting like a strange feedback of sorts, it was sparking without the motor turning over, which could of been because I hadn't disconnected the module inside the car. I have since disconnected the module from inside the car.

Since I know the ZX dizzy will work alone, but not with the ecm, or maybe it will and something else is interfering is what I need to find.

Too many questions and not enough answers...

1. Did you not understand that the negative from the coil splits and one branch goes to through a resistor and the tach before going to ground and the other branch goes to the ECU? (Actually there is a thrid leg that goes to the TIU, but that should be unplugged.)

2. Where did you get the ZX distributor?

3. Do you know if you have a good distributor?

4. Have you downloaded a copy of the FSM?

5. Can you read a wiring diagram? (Not intending any offense, just gauging the audience.)

6. Did you install a high impedence coil to deal with the fact that you bypassed the resistor?

7. Can any wire from the connector to the TIU come into contact with ground? If so, break out the electrical tape.