360 problem child

What do you mean by "FI ECU". You have a gated car if I recall correctly, so I assume you're referring to Fuel Injection ECU? Do you mean the LH motronic RELAY controls the LH Motronic ECU?

Well, the ignition turns on the Motronic ECU, the Motronic ECU activates the Motronic Master Relay and the relay sends power to injectors, coils, etc, and it also sends more power to the Motronic ECU on 3 different pins. I assume this is to power the transistor driver circuits for controlling the injectors, coils and things.

 

The right side ECU (Main computer controlling right half of the engine), controls directly the fuel pump on the right tank of the car.
The left side ECU (The slave computer controlling the left half of the engine), controls the second fuel pump on the left tank of the car.

If you had a fire in the engine bay, it is entirely possible that the ECU on that side is damaged.

I presume you have an OBD2 scanner that can read the ignition angle of the crank shaft compared to its TDC position. What you are saying is:

Left bank: at 1000 RPM ignition is at 11 degrees before TDC, and at 2500 RPM ignition is 27 degrees before TDC.
Right bank: at 1000 RPM ignition is at 5 degrees before TDC, and at 2500 RPM ignition is at 27 degrees before TDC.

I do not know the relevance of TP 3.1 (Throttle Position). What is 3.1?

 

The relays are controlled by their same side ECUs and the relays supply some power to their same side ECUs. The ECUs control their same side injectors and igniters. Only the intakes are on the opposite side of the car (i.e. MAF and throttle body).

If the LH Motronic relay above the A/C relay is hot, that would not explain why the RH bank is failing. Seems you have more than one issue with engine control.

So the fire was on the left side of the car. I can't explain why the left bank is still operating if there is a short on the left hand side (due to a fire).

If you turn on the ignition and don't start the car, does the relay still get hot (after, say, 5 minutes)? If so, it might be easier to track down the fault.

 

I had a very similar issue not too long ago, minus a fire, and it was a bad fuel pump.

 

Similar in the fact that the same side Master Motronic relay was hot and the opposite bank was not working?

 

If the ECU itself is drawing too much current, you can check this by disconnecting both LH Motronic ECU plugs and shorting pin 31 on the LH ECU inboard wiring connector (or lower plug if you have a spider) to ground. Shorting this pin (socket) will keep the Motronic relay active. You may need a thin piece of (lock) wire or fusewire to go into the socket of the plug.

Image Unavailable, Please Login
This should keep power going to all the engine sensors/devices powered by the LH Motronic Master relay (but stop relay power going to the ECU).

Since we don't know what temperatures are normal for these relays, I suppose we shouldn't go too far down the wrong rabbit hole. Take great care when removing and reinstalling the connectors (not to bend pins). I suggest temporarily disconnecting the battery with the cutoff switch when doing this.

 

This is getting very confusing...

The rs MAF feeds the left bank. If you put your hand over the rs MAF and the engine died, it means that the LH bank was working and the RH bank wasn't. You also said this:

If hardly any vacuum, it means that the RH bank isn't working.

LS motronic relay is getting hot. LS motronic powers the left bank and some components in the left ECU. Pin 31 goes directly to pin 2 of the LH Motronic relay. The LH ECU normally provides a ground to the coil (pin 2). By grounding pin 31 of the ECU harness (not the ECU) you are imitating the signal from the ECU. The relay will turn on and provide power to:

Image Unavailable, Please Login

However, it also provides additional power to the ECU (on 3 different pins). This may nor may not be the cause of the high relay temperature. However, I've just noticed that there is an easier way to isolate the power going to some of these components. If you pull fuse 60, power stops going to the thermocouple ECU. If you pull fuse 61, it stops the additional power going to the ECU. If you notice a significant drop in relay temperature with these fuses pulled, then you know that these devices are possibly at fault. But since the LH bank is working, I can't say for sure that the high temperature is a fault.

 

For info, the immobiliser sends an unlock signal to only the RH ECU. Upon receipt of the unlock signal, the RH ECU then sends a signal to the LH ECU to unlock that. The left bank is running, so that means at least some circuits in the RH ECU are working.

If the RH bank is not working (properly), I think we should focus on that.
If you have fuel pressure on both rails (without jumping relays), then it's a good sign that both the rs Motronic relay and the rs fuel relay are working. You just have to figure out why you have no injection/ignition. Is the rs Motronic relay providing power to the injectors/igniters and all the other devices? With your voltmeter are you getting power at fuses 38 (O2 sensors), 39 (RH Motronic "additional" power) and 46 (ABS/ASR)? If you have fuses with cutouts in the back of them, you could test both ends of the fuses (red probe on fuses, black probe to ground).

Image Unavailable, Please Login

 

Sorry.. wires crossed.
Fuse 60 powers:

Left bank O2 heat
Left bank exhaust bypass valve
rs MAF
Left bank anti-evap valve

Thermocouple ECUs, don't have fuses (after the Master relay). Neither do injectors nor igniters

 

OK. I just assumed that the variable intake valve system on the 360 used crossflow at idle rpms (I assumed that you were checking the airflow at idle/no load). Crossflow uses the longer path for more torque at low rpms. However, I don't know if it exclusively uses the longer path or both paths at low rpms???

If the left bank is not working (cold exhaust on the lhs), then the heat on the relay makes more sense.

Thanks, so that means it only gets hot with the engine running. We just have to figure out what extra is working with bank trying to run run.

Thanks for telling me you have a test light. It doesn't tell you what the voltage or current value is, but it's better than nothing. On that note, you'd need specialist tools to see what data is going between the R ECU and the L ECU. You could do simple wiring resistance checks between the ECUs, but it won't tell you if the data is valid. By the way, is the Left ECU communicating with your OBD2 reader? As I understand it, to get the OBD2 reader to talk to the ECU, it has to be unlocked by the immobiliser/RH ECU. That may be a sign that your Right/Left ECU comms are ok.

P.S. I haven't had any experience with MAF cleaner on a running engine, so I don't know if it's supposed to kill the engine or add more combustible material.

 

If you are getting the car to run, even only bank 1, then the two ECUs are talking to each other on their dedicated CAN bus. If they cannot talk to each other, ignition is disabled from the very start.

Can you check the injector signals on one or more of the injectors on bank 2? The left bank? You would need to make a special pigtail connector to check the drive signal because the injectors have to be plugged in during the test.

 

So ignition on both banks, Mitch?

There's a plug on the engine which feeds power to the LH injectors, igniters, O2 heat, exhaust bypass valve solenoid, rs MAF & LH evap purge valve. Just wondering if the engine will still run with this plug disconnected. If so, can you run the engine to see if the LH relay gets hot? Then it would be a matter of figuring out which of the above devices is causing the issue. e.g. as Mitch suggests, the injectors ... as current only flows from the relay to the injectors when the engine is running.

Image Unavailable, Please Login

 

Correct. The car cannot be started IF there is no communication between the ECU.

 

I would only be guessing on an engine like this. The throttle position sensors (and MAFs) are wired directly to their opposite banks (see post #40). But if you look at the intake manifold, air can be taken from both sides.

Image Unavailable, Please Login
Image Unavailable, Please Login
After what you have told us, what happens to the airflow at various throttle positions, I don't know. I was relying on references from sites like "Aldous Voice".

https://aldousvoice.com/2013/01/07/ferrari-360-air-intake-system/

At low rpms (including idle), the shorter air tracts are sealed, so the air going into a particular bank must (only) be coming from the opposite side of the engine. At high rpms, it seems that both sides are used, but air likes to take the shortest path, so the same side air, MAF and throttle body will predominate, but I don't know if MAF and TPS values on both sides are used in the ECU's calculations for a particular bank.

If you blocked the air going into one MAF at idle, you are stopping the air going to the opposite bank and will stop the opposite bank operating. If one bank is not operating at idle, and you shut off the air going to the good bank (by blocking the MAF on the same side as the faulty bank), the engine will stop running. This is what you described, when you blocked off the rs MAF but you still insist that the LEFT BANK is faulty.

The manual does say that the "engine" will be brought it idle if a motorized throttle breaks down. Whether loss of data from a TPS also produces the same effect, I don't know.

 

Jack,

I recommend you adopt a systematic approach to troubleshooting this thing.

One bank is running while the other is not.
Is one cylinder or all four are dead?
You have ascertained fuel pressure at the rail, good.
Is there fuel coming out the injectors? ______ ?
If no, there is your problem, chase that down until it is no longer a problem.
If yes, there is fuel at the injectors, then move on to test for spark.

 

Agree with you 100% on that.

Here's technique that's worked for me: 1) State a hypothesis, 2) Test the hypothesis, 3) Reject or accept. Maybe this is the same thing you are saying, Mitchell.

This was done once already. The hypothesis was that there is no fuel coming from the injectors because the fuel pump is bad. A test showed there was pressure at the rail, so that hypothesis was rejected.

Possible next hypothesis: No fuel is coming from the injectors because no trigger signal is arriving at the injector.

 

Or no power. Check all 8 injector connectors for 12 volts power (key on). With a fire, we can't assume wiring is ok. The trigger signal is actually a ground from the ECU (engine running). A test light may be ok to test these (if you have no oscilloscope)? The immobiliser unlocks the ECU to allow triggering. Presumably, cam and crank sensors also participate in the process.

Have we established the significance of:

 

I don't believe so. As you may know, the ECU calculates spark advance using engine RPM, mass air flow, throttle position (TP), and coolant temperature. One might assume at least one of these four variables must be inducing a signal that differs bank-to-bank.

While this is something that could shed light on the problem, I think your instructions on checking injector voltage should be executed first.

Please check if the steps below make sense:

1) Ignition key on, engine not running, the injectors should read ~ 12 v from the positive lead of the injector connector to battery ground, and current should read zero amps.

2) Under the same condition, the voltage from the positive lead to ECU ground should be zero, since the ECU ground circuit is open when RPM=0; current should be zero amps.

3) Ignition key on, but now with engine running, current should be non-zero from the positive lead to ECU ground.

Would be nice if the testing reveals a difference, bank-to-bank.

 

@jackgt It has been suggested elsewhere that it would be wise to check individual cyclinder (outlet) temperatures with an infra red temp sensor. Nothing you have said so far has convinced me that the right bank is running. Maybe you could at least acknowledge that you understand how Ferrari controls airflow to the cylinders at low rpms?

Image Unavailable, Please Login

Yellow is idle airflow path.