What would cause all four injectors to constantly buzz at a high rate of speed when you turn the key on, but without the engine running? It's way faster than when you hit the butterfly with the key turned to the on postion. It doesn't happen all the time either.
I got it fired up and then suddenly it started to bog then clear up and run fine and then bog again.
Now it's just flooded so bad I had to quit for the night.
When it does happen the injectors will all in unison buzz very fast as long as I leave the key on. It's not the fuel pump because I pulled the plug on the injectors to make sure.

It just started after I pulled the engine to fix some leaks. So it's something I did, but I made sure to mark everything before I pulled it apart. I'm thinking that this old harness finally broke somewhere maybe?

If I can't figure it out I'm going to try another harness that I have and see what happens.

Any ideas?

The common ground connection to the injectors, under the plenum, top case bolt.
The ECU plug
The CHT plug
Shorted wiring harness in the engine bay somewhere.

Start at the ECU and at the Relay board.
Follow those harness's to every termintation point.
Look at the connections on the alternator and starter also.

It sounds like a loose connections.

Rich

Thanks Rich I'll follow your advice and see what I come up with. I'm done messing with it for the night and decided my time would be better spent studying the wiring diagram.
I figured as random as it was it had to be a connection somewhere.
Thanks again

What did you unplug? That is the question.
For a learning point, try to never unplug the ECU.
Instead, unbolt it from the battery tray and lay it on top of the motor to remove the motor.
The older plugs are ...well....old.
Rich

I unplugged everything. Yes, even the ECU from the harness. I was trying to avoid the problem I have now. I was trying to avoid stressing the harness with the weight of the ECU possibly twisting.

When I first turned the key to pressurize the system for fuel leaks is when it first happened. I was stumped at first and thought my fuel pump was dying. Unplugged it and the buzz was still there from the injectors. What's weird is that it is a very, very rapid buzz.
I'm sure the bogging and then smooth running was the random glitch kicking in.
I stopped after it bogged to a stop. I smelled so much fuel the problem was obvious as to what was happening.

Re run the wiring.
If you need help, ask.

There are color wiring diagrams out there, but the FI wiring is verfy simple if you allow the harness to lay in the spot it has been for 30 years...it will tell you.

Rich

Get some readin done, welcome to Djet.
Its simple.
It measures air, heat, load and fuel.
Air is measured by the throttle position sender.
Heat is measured by the cylinder head sensor
Load is measured by the Manifold Pressure sensor
Fuel is always at 32 psi, and the duration of how long the FI is open is controlled by a map in the ECU.

So, you hav either a shorted TPS (Throttle position Sensor) or you have a ECU issue.
Take the plug back oout of the ECU.
Un bolt the ECU
With it in your hand, plug the thing back in.
The plug is hard to get on correct with the ECU in place, the bottom of the wire hits the body of the car.


Read up here...the holy Djet site.
http://members.rennlist.com/pbanders/DjetParts.htm

Rich

Awesome site Rich! I haven't seen that one before. I'll read up on it.

I guess I should of said something about the car. It's a 70 that I've owned for a few years now. I found it under a tarp in a guys driveway. I bought it and then took it straight to a friends storage yard where it sat for almost 3 years. My 71 at the time was still on the road. (I've since sold off the 1.7 in it and started work on a 2.0. I've gone back and forth so much on conversion ideas that I may just go with the 2.0 or 2.2 6 I have now after all....paralysis by analysis.) I'm off till the end of January and decided now was a good time to get it going.
This harness has been cut into by the PO. I may just replace it with the known working one I have. I'll mess with it a little bit, but I'm already thinking it's better to just replace it.