Installing modern fuel injectors in the 465 2.7 Motronic

Hi all!
This winter I've decided to upgrade the injectors in my 456.
I had the original Bosch EV-1 injectors tested at a mate's workshop and discovered that 10 out of 12 fuel injectors weren't delivering enough fuel.

I could have refurbished the injectors, but instead I started looking into replacing them with newer and more modern injectors. It's been 30 years now since the car was new and technology has progressed quite a bit since the car was produced. I'm hoping that a newer generation injector will atomize the fuel better, giving better performance and better fuel economy.

I'll post a list of parts and part numbers below.

New injectors:
After some research I found out the Bosch 62391 injector from a Chrysler 3.5 V6 has the same flow rate at 240 cc/min.

The Chrysler injectors are EV-14 style/generation injector. The injector body is much slimmer compared to the EV-1's fat body and they are also much shorter. The electrical connector is also different and will need an adapter.

A set of 12 cost me less than 400 USD, which is way less than the 1200 USD for a set of new old stock EV-1 injectors for the 456 cost.



Fixing the fuel pump rubber and check valves:
I also had some issues with the check valve on the fuel pump leaking and not holding pressure in the fuel rail over time. This was adressed at the same time. New check valves were ordered for a sum of 30 USD each: BOSCH 1 587 010 536.
After removing the fuel pumps, I discovered the anti-vibration pad underneath the basket was shot. So was the rubber holding the fuel pumps in the basket. New pads were ordered from Eurospares and fuel pump holders were ordered from Fiammenghi in Italy.

Anti-vibration pad in tank:
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Installing new injectors:
So on to the point of installing the injectors.

As mentioned earlier, the new injectors are shorter and need to be lengthened by 14 millimeters. I ordered a set of 12 short injector top hats from Speedingparts.eu .

I had also purchased a set of 12 USCAR (injector) to EV-1/Jetronic (engine wiring) wiring adapter. Initially this was a short type, but turned out this didn't work out due to the adapter fouling the intake manifold. I therefore needed to get another type of adapter with wires, which was more flexible.

Installing the injectors was straight forward, just make sure to lube all the o-rings.

Engine started easily and ran perfectly. Throttle cable had to be adjusted and the intake had to be balanced, but that was on the to-do list before starting on the injectors. I have yet to test this set-up on the road, but that will have to wait because winter conditions.

Don't use these electrical adapters:
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Old injectors:
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Size comparison:
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New electrical adapter:
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Installed on the engine. I admit the wiring could've looked better. I would've been as well if I could use the shorter adapter for the electrical socket.
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Engine balancing.
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Parts:

Injector parts
Injectors: Bosch 62391
14mm Injector spacer
Electrical adapter EV6 to EV1

Fuel check valve: BOSCH 1 587 010 536
Fuel pump support

 

Video of starting:
https://youtube.com/shorts/QX4nGp_tCNI?feature=share

Revving the engine:
https://youtube.com/shorts/2gnSHsJ3YC4?feature=share

 

The OEM has 4 holes that directs the fuel towards both intake valves. The new injectors have the same.
The fuel is atomised immediately when exiting the fuel injector.

Choosing a injector with a larger flow rate could lead to cylinder wash, due to over fuelling. However a newer ECU should be able to compensate a slightly bigger injector based on lambda values.

 

That sounds about right with the 10%. I did have a look at some bigger injectors at Summit Racing, but backed out from that idea.

That's when I found the 240cc injectors which are the same as the OEM ones

 

You're probably correct about any adverse effects from the changes.
On another note, I have gotten all new injectors for a fraction of the cost of new OEM injectors!