Sd1 rover v8 3.5 efi flapper injector timing?

[OCTOBOX]

Hi all 

i am new to this forum business so please bare with me. I have a 3.5 efi and can’t for the life of me work out how the ecu knows wich injector to open. I know it picks up a pulse off the coil that comes from a halleffect sensor on the dizzy. But all the ecu recives is 8 identical pulses? How does it know to squirt on say cylinder 7 and not on say cylinder 2 

[Bowie69]

Flapper EFI is not sequential, nor is hotwire.... It has little benefit in the real world.

 

[OCTOBOX]

Hi bowie69 so you are saying it just squirtes fuel at any of the 8 ports regardless of wether the inlet valve is open or closed. Then when the inlet valve opens the incoming air will drag the puddle of fuel through haha 😂. That has to be the crapest system i have ever heard no wonder they don’t just fire up on the first kick.  

Thanks for the reply🙂

[lo-fi]

It's how most fuel injection up to the very modem stuff works. There's vanishingly little advantage to sequential injection, as Bowie says above, for the simple reason that at anything more than very moderate loads the injectors are open significantly more time than the inlet valves. There are many things to complain about in Land Rover fuel injection systems, but batch fire injection is very low on the list. 

[Bowie69]

Yup, as above, it sounds terrible, but has worked for all efi for decades until , say, the mid 2000s where sequential started becoming  more mainstream.

[OCTOBOX]

Fair play i guess it makes sence to of preloaded the fuel instead of trying to jet it all through in such a small time frame. It kinda makes me think spray pattern shouldn’t be so crucial if it hasn’t got spray       Perfectly around the valve just dump the right amount in and then suck it through right? But then i guess a neat spray is the correct amount and anything other than neat is less fuel? 

 

Cheers for the info guys its much appreciated!

[lo-fi]

57 minutes ago, OCTOBOX said:

dump the right amount in and then suck it through right?

Pretty much this. The pressure fluctuation as the flow in the intake runner stops and starts helps with atomisation. The angle the injectors sit at in relation to the ports is kinda important, but not super critical unless you're trying to squeeze every last drop of euro rating out of your fuel, as is flow pattern. 

[OCTOBOX]

So does anyone know if the 4.0 thor engine is sequential of not?

[FridgeFreezer]

Why do you care?

Sequential has almost no benefit apart from emissions at idle, and firing at the back of a closed valve is actually beneficial, it cools the valve / charge, vaporises the fuel and allows it to swirl.

[Bowie69]

They didn't not do it because it wasn't good enough -quite the opposite, it *IS* good enough.

[elbekko]

4 hours ago, OCTOBOX said:

So does anyone know if the 4.0 thor engine is sequential of not?

It is.

[OCTOBOX]

6 hours ago, FridgeFreezer said:

Why do you care?

Sequential has almost no benefit apart from emissions at idle, and firing at the back of a closed valve is actually beneficial, it cools the valve / charge, vaporises the fuel and allows it to swirl.

I care because i like to know how things work and what i am dealing with. Hence joining this forum and asking questions. Although I appreciate the info. 

[smallfry]

23 hours ago, OCTOBOX said:

So does anyone know if the 4.0 thor engine is sequential of not?

It is. Apparently.

But is produces no more power or economy than a Hotwire 3.9

Does produce slightly more torque though, but that more by virtue of the inlet manifold.

[Escape]

The higher torque at lower revs is indeed due to the longer intake runners. At the cost of a very little bit of top end power.

The Bosch sequential injection was for emission purposes, to comply with Euro3 and similar.