Restoration Project

I was not aware anymore that the ignition cables cross over. This makes a fault in the ignition system a lot less likely.

Then I would really have a look at the fuel system. Are these the cylinders the farthest away from the entry of the fuel line?
I have heard from ( very powerfull) engines breaking because the cylinders on the end of the rail where leaning because they did not get enough fuel anymore.

Maybe also something is wrong inside the fuel system that prevents the fuel from flowing easy ( can be something as easy as a swollen rubber line). The pump itself should have more than enough pressure to run the engine in idle.
Thinking about this, these are all faults that would appear under full power more than under idle....

If you restart the engine instantly after the cylinders where gone, what happens then? And, what happens if you rev the car up?
Also check the electrical connection to the injector valves. Maybe you have some sort of verdigris or so that prevents the valves from opening the whole time. Also check the side towards the ECU. As soon as the engine gets warmer, the opening time gets shortened, and then they just do not let enough fuel pass for an ignition.

If I try to rev the engine up, I have to modulate the throttle to let it climb in RPMs. If I give it full throttle, the engine will die completely. It revs much easier when cold. The injector valves are paired from left to right according to the wiring diagram and confirmed by electrical tests with the multimeter. I would assume then that the opening time is adequete since it seems to be enough for the other side to fire. I have cleaned the contacts on the valves.

The entry fuel line, pressure regulator, and return line are all located on the passenger side fue rail, the functioning side. There are two braided lines which then cross to the driver side rail. I haven't really been able to determine a clog anywhere on those lines.

Once I have an extra set of hands, I can do some more tests. Doesn't help that everything is covered in snow now.

Camshaft timing is okay?

I would check the throttle valve and the respective sensor at the front below the idle valve, especially the
connector.

Cylinder 5 is is firing, so Cam timing on that bank must be correct. No reason to think it wouldn't be anyway.

The Idle Valve functions as supposed to when triggered during the output test. Could that sensor really cause this? I have confirmed continuity with a multimeter between those pins on the plug and the pins on the ECU. I do still get an occasional error code for that sensor although I haven't been able to read them recently.

Below the idle valve, check the connector of the throttle valve sensor (Drosselklappenpotentiometer)

You think that the ECU does not know how much Fuel it is supposed to inject.

I know of the weirdest problems resulting from a corroded connector on that sensor, from idle problems to an engine shutting down to Rodeo rides when triggering the kickdown to transmission emergency mode - it can be the cause for so many problems...

It don't read the rest of this thread... but YOUR description look to me similar like my "Luftmassenmesserproblem"


Maybe sometime I'm in mood to tell about...

I have ruled out an ECU communication problem because:
The right bank of cylinders fires correctly and each injector on that side is paired electrically to a cylinder on the left bank. Therefor all injector valves should be opening for the correct amount of time.

I have also confirmed that all eight valves are opening by using a mechanics stethoscope to listen to the actuation.

In Antwort auf:

---

and each injector on that side is paired electrically to a cylinder on the left bank.

---

Who did tell this lie to you?

Have a look at the attachement..

and this one...

2

BUT this one means that what you mean.

This is a bit stupid... the valves open and close not at the same time, why should the injektors do it?

The wiring diagrams and my digital multimeter. That's how it works.

That is the wiring diagram I have been working with. 1991 Model.

Many early injection systems run a batch fire or semi sequential fire. The injectors are paired according to the firing order to fuel consecutively firing cylinders. It does work and at high RPM it makes no difference whatsoever since the injectors are almost always open.