cranks but won't start

Start at the beginning; fuel pump fuses and relays. If they are all fine, fuel pump connectors, and where these join the wiring loom.

 

Very strange. How sure are you that you didn't have spark before?

Do you know how your aftermarket immobiliser disables the car? Does it act on the fuel pump circuit? Anyway, as said above, go through basic fuel pump diagnosis.

Do you have one pump or two?

Here is the circuit for the pumps (2.7 car):

https://www.dropbox.com/t/vxpPH6KivjWXlyBX

You can jumper the relay to remove control issues via sockets 30 and 87 on the relay socket, although I don't know at what point the immobiliser interferes with your circuits.

 

Apply 12V directly to the pump, does it build pressure at the fuel filter?
Apply 12V directly to the output of the Fuel pump relay pins (after removing the relay), does it build pressure?
Install relay, find a way to apply Ground to the drive pin of the relay, does it build pressure?

If all that is a yes, then it is in your immobilizer alarm thingy. Rip it out.

 

+1

This can be done with a jumper wire on the relay power contacts. If the engine runs perfectly with the jumper wire, then a pressure check is optional.

I just realised on the 2.7 that the relay coil requires an earth from the ECU. Unless you can find the provisional immobiliser connector "59302", I think it will be hard to find a place to put a earth without interfering with other circuits. Whether the earth (in the ECU) is always there whatever the sensors are telling the ECU, I don't know. The problem with the fuel pump relay coil circuit is that it requires an earth and power (hence the jumper wire is easier for initial faultfinding).

 

The fuel pump relay has permanent 12V supply so it is very easy to test the pump(s). You don't need to switch the ignition "on", just jump the sockets for pins 30 and 87 with a length of wire having male spade pins at each end and listen to the pump sound. With the jump wire(s) in, you can also try to start the engine.

Relay socket:
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I'm still trying to figure that out. There are just so many inputs into the ECU at specific times (from the ignition key, immobiliser (on the 5.2), crank sensors, etc) and there are variations other than 2.7/5.2 variations.

My (revised) take on the 2.7 (comments welcome):
Battery power is always on the ECUs (to retain fault and learned data).
When the ignition is turned on, the ECUs will go though a quick test cycle. It will probably be at this point that the ECUs send out a "happy" signal to the ECU relays to put power on the various engine sensors and provide power to the fuel pump relay coil.
However, as mentioned before, the fuel pump relay coil/s still need an earth. This will happen during cranking (at a specific, relatively low rpm) based on the crank sensor signals.
During cranking, injector and spark timing will be computed from things like the crank and cam sensors.

It seems odd that you have spark and (now) fuel, but still no engine operation. I can only think that the signals from your cam/crank sensors on that particular bank are so weak/unreliable that the ECU can't compute fuel injection timing (but sometimes spark). Note that resistance checks on crank sensors don't always prove that your crank sensor are ok. You may still have an intermittent problem with the crank sensor or crank sensor wiring.

Note: Sometimes, the cam and knock sensor plugs are accidentally swapped over during engine outs (preventing engine start), but this doesn't seem to be the case as you said the engine was running fine until you put the shields back on.

Anyway, our apologies for not getting your car back into action (that would have been a nice Christmas present).

(EDIT: I had to make a couple of edits to this message. I previously said that coilpack power required a happy signal from the ECU. Coil pack power actually comes directly from the ignition key. No ECU input required, but, of course, the ECU is required to send trigger signals to the coil pack via the separate ignition power modules on the 2.7 cars).

 

The fuse is downstream of the ECU-controlled fuel pump relay, so no fuse power would still not eliminate a crank sensor issue.

ex-USSR countries seem to be a common source for these parts. Quality control seems to be a bit "hit and miss", but you should be ok, at least in the short term Some folks keep these items in their tool kits.. just in case.

 

Since you mentioned, I have bought a number of parts for my 348 and other cars from a company in Estonia (https://spareto.com/). They have practically everything by Bosch but also by many other manufacturers. You can select your Ferrari model at the website and see what they have, search by Ferrari p/n or by Bosch part number. Their prices are about the lowest you can find (and drop significantly when they remove the VAT as you order or login).

The thing that amazes me most is that they ship very fast (items that are in ready stock), by DHL Express, but at low prices. Just received some sensors for my Saab this morning (24 Dec) that I ordered on 21 Dec late evening. It appears that DHL Express is not affected by Covid at all (at least not for shipments Europe to malaysia).

 

I fully agree with the positive comments about DHL . Unfortunatly I forgot to specify this option and have been waiting for mailed package from Superformance since Dec 8 . I guess the Christmas mail overload is slowing things down. They are always quick with DHL !

 

The ground wire is probably attached to a braided shield wrapped around the other two wires to stop electromagnetic interference. You don’t want random pulses from other sources messing up your engine timing.

 

Do you have a Windows computer or Mac? Do you have an iPhone or iPad or similar? If Windows, just right mouseclick on the wiring diagram file and select "Open with..." from the drop-down menu, then select Paint. The tools in Paint should allow you to magnify the image (there is a magnifying glass in the Tools section). If you have Windows 10, right mouseclick to reduce the size of the image.
If you download the image to an iPhone or iPad using Safari, you can expand and shrink the diagram with your fingers.

I bought a second hand set of original diagrams from a fellow FChatter U$1100, but I'm sure you don't want to do that.

 

The coil gets power from the battery via relay "O".

The earth is provided by the ECU on the SG (pink-yellow) wire. That is, via plug C on the relay panel, then plugs 59302, 41024 and 41052 (pin 5). Pin 5 goes to pin 3 on the LH Motronics ECU.

 

The diagrams, unfortunately, don't show the relay pin numbering, but you may be able to figure it out with a multimeter. The F348 diagrams show the pins, but Ferrari have mislabelled some of them

 

The 0.5 is the wire cross-sectional area in square millimeters (basically the wire gauge, but in metric units). As far as I know, the /2 means that there are other wires in the harness with that colour (perhaps an advisory to be careful not to mix it up with other wires).

 

Just to clarify... the /2 is a random number assignment. There could be 5 wires in the harness with the same colour.

/1, /2, /3, /4, /5

 

It is possible that your Cam (Phase) sensor has failed. This sensor is very different from the Crank sensors (although in a similar housing) - it is electronic and can fail suddenly.

About the cheapest (Bosch, from Lithuania) - https://www.ebay.com/itm/RPM-Camshaft-Position-Sensor-CPS-GAZ-Chevrolet-Ferrari-UAZ-SOBOL-VOLGA-OMEGA/133558435250?hash=item1f18b3fdb2:g:magAAOSwjGxfmAfV

You cannot test the Cam sensor with a multimeter but it can be bench tested using a power supply and an LED diode as follows:

1. Make sure which pin gets positive supply at ignition "on". This supply comes from the ECU and it can be 5V or 12V. Also determine which pin is ground (should be the black wire).
2. Take the sensor out and connect a power supply (5V or 12V) to the supply pin (+) and the ground pin.
3. Connect a small LED diode, its positive leg to the positive supply and the other leg to the third (remaining) wire of the sensor:
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Use only a small LED, ~3 mm diameter, as a large one may overload the sensor. Depending on the voltage that the sensor operates on (which you are also using for the test), you have to connect a resistor in series with the diode: 470-500 Ohm for 5V, 1-1.2 Kohm for 12V.

Then, move a screwdriver close in front of the sensor - the LED should momentarily light-up and go off when you move the screwdriver away.

 

1) Check the codes. I red that 5-8 CEL came on. Have codes been read?

2) Check for spark. These work great. Image Unavailable, Please Login

3) Check to see if injectors are firing. Use a Noid light. Image Unavailable, Please Login

If you have spark and fuel,
4) Check compression.