348 Start problem... or not?

That indicates to me you had an issue with your ECU connectors (contamination?) or that swapping them over put one of the ECUs into a position where some of its pins were no longer required. However, looking at the wiring diagrams, the pins which are only used on one bank shouldn't cause a misfire. By the way, do you have a 2.5 or 2.7 engine management system?

In your video, after the first start failed, I see you pumped your accelerator pedal a few times prior to the second start attempt. I can't see how this would do anything on a fuel injected car.

What do you mean by booster?

After your battery replacement, did you allow a re-learn of engine idle?

 

I got a gts so 2.7

My battery change was about one year ago so the re learn happened already

I didn't push with my feet expecting something, it's just something I do without thinking about it.

If I buy such a set will I be ready to check my fuel pressure?


https://www.amazon.de/gp/aw/d/B0D4YGVX3Q/ref=ox_sc_act_image_1?smid=A2X2IS1I8BHRL9&psc=1

 

Looks like that kit has every possible thread combination, so you should be ok. Can you see where to plug it in?

Make sure you work with a cold engine. Some fuel may squirt out when you fit the gauge. Put a rag around the fitting.

 

I don't see how any of the adaptors shown in the kit can be used on the 348 to measure the fuel pressure. What you need is an insert-adaptor with a T-off (example: https://www.merlinmotorsport.co.uk/p/oil-pressure-gauge-t-piece-m14-x-1-5-tp-m14x15):
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The main thread of this adaptor is M14 x 1.5 with a 1/8 NPT offtake. The M14 thread matches the threads of the fuel rail but you would need to machine an inverted flare into the adaptor's male end for the 348's fuel hose to connect to it. You will also need a schrader valve (for petrol) like this one (example: Motorcraft Fuel Injection Fuel Rail Pressure Relief Valve Front CM-3461 | eBay):
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This is the "service port" I fabricated using the above parts (my service port is unused, for sale now):

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This adaptor can be inserted between the fuel rail and the "U-turn" hose at the rear of the fuel rail. Another convenient point to insert a T-off adaptor is at the top connection of the fuel filter but I do not know the thread size there (could also be M14 x 1.5). Then, you can use a simple pressure gauge and hose which has a connector for standard schrader valve (like connector to the tyre valve), example: Fuel Pressure Tester Gauge | eBay

 

today i did get my set and even if there are a LOT of part... Indeed there's nothing for M14 thread.
I underqstand the purpose of the T, but there was already some in this set. However it sucks that no M14 part can be linked. I am really upset.
Let me try to find something like you in europe.

 

that should do the trick isn't it?

https://www.amazon.de/Generisch-Edelstahl-Seitenl%C3%B6cher-NPT-Innengewinde-%C3%96ldrucksensor-Anschluss-Zuleitungsmessger%C3%A4t/dp/B0DGF9QQ4P

M14 on both side (male/female) and 1/8npt on top for the manometer (which i assume is the same dimensions as the one of my set.
What do you guys think?

 

How old are your spark plug wires? They should be pliable and limp. If they are stiff or hold their shape, they're likely aged out.

Mine were so stiff they would hold the plug end up.



sjd

 

The adaptor you show can be used but you would need to machine an inverted flare into the male side (like on my middle picture above):

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I don't see any fitting in the fuel pressure gauge set that would enable connection of the gauge to the 1/8 NPT port on the adaptor. You will need to buy a Schrader valve, compatible with petrol, that connects to 1/8 NPT. Then, you can connect your pressure gauge to it via the short rubber hose provided (the hose with a Schrader valve connector).

In my case, the Schrader valve I bought has M8 x 1.0 thread so I had to make an adaptor (brass) M8 x 1.0 female to 1/8 NPT male in order to connect the valve to the 1/8 NPT female port.

 

Oh my god. I understand what you say ...
And I got no machine able to do that.
How do other people do to check that damn pressure?

 

On second look, one of the small adaptors may fit into the 1/8 NPT offtake. Check what thread size is on the bit marked with the red line on the photo (doesn't look like 1/8 NPT but it might be).
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this could do the trick for the manometer.
However this doesn"t help linking the T part to filter and / or injection ramp :/

 

This would solve your problem: Ferrari 348 Fuel Pressure Check Adaptor | eBay

 

I could find a way to test the pressure in entry of injector rail.
Then i powered the gasoline pump and... Everything was normal. 3.8-3.9 bar.
Btw i checked the fuel regulator by taking away the plenum hose and nothing came out while pumps were running.

So, two more possible cause that are not responsible :/