the differences in batch-fire and sequential efi hardware?

[shane96ranger]

on the eec 4 pin 58/59 is bank 1 bank 2 or

injector 1 and injector 2 on sefi.


bank is not 1234/5678 wich would be actual bank as in left side right side


its actually 1458/2367



on sefi its usually obviously the firing order



bank fire on the ford is single shot of juice per cycle for lopo....on the 351 lightening and custom tunes they double shot the injectors per cycle for some parameters.


on the eec4 fords the rails and intakes are the same, even the fuel pumps, regulators and lines.

i thought you wer talking about the hardware on the pcm board

Very good info. Please help me with my understanding. I read about this a while back on a turbo/supercharger forum I believe. I read that some SEFI systems (not necessarily Ford's SEFI) systems kick into batch mode at WOT anyway. Or is this what you mean by the double shot custom tune?

This is also where I believe I got the info that I posted earlier that "some people prefer this because it allows the fuel to vaporize, and your engine runs cleaner and more efficient." Feellnfroggy disagrees with the statement, and I only know what I read....it could very well be wrong, or maybe I misunderstood.

 

[bobbywalter]

froggy is right.....for low speed ....at high rpm the injectors cycle so rapidly..its just a metered stream for any effective description

 

[cammeddrz]

ok so i got to thinking. i used to have a '97 LT1 camaro. when i sold it i pulled my bored + stroked 396 LT1 out and bought a stock lt1 and put back into it. as i was hooking everything up i noticed that the new lt1 didn't even have a crank pos. sensor. not even a hole in the timing cover for it. naturally i just taped up the connector out of the way. i called the wrecking yard and found out the engine was from a 1994 camaro, their book said they interchange. i guess a 1997 engine would interchange to a 1994 car but not vice-versa...the holland interchange system strikes again
it ran absolutely fine with a C.E.L. throwing a C.P.S. code

all of this was years ago but it came to mind when i was looking up the lt1 engines horsepower ratings it said that the 1992-1995 LT1s were batch fire and the 1996-1997 LT1s were sequential . but they had the same hp ratings!
that explains why the older engine didn't even have a crank pos. sensor in it. and i'd wager that my originally sequential car kicked over to a batch-fire mode without one

 

[AllanD]

Yeah, even at 800rpm the injectors are firing at 60pulses per Second, so the difference between "Batch fire" and SEFI is little more than wishful thinking af far as "fuel pooling" goes

and on a 4.0 it's two cylinders on one sied and one on the other that fire together.

Now as to "what's different about the HARDWARE?"

all 1990-92's were "Batch fire" and used the "grey" stem pintle injectors

The 1993 4.0's were still Batch fire but used the "Red"
(some replacement suppliers make them "Black") injectors that use a disc pintle
these are easily identified by their FOUR squirt holes at the buisness end.

These same injectors were used on the 1994 SEFI engines


The rails are all the same, the lower intakes are different starting in 1995 with the
switch to the plastic upper intake, because at the same time they milled intake down
to allow for the 8mm thick thermal isolator and the fuel rail that mounts between
the upper and lower intake

SO if you use a 1995-00 lower intake you'll need to use the proper gasket set
so it comes with the thermal isolator.

Lastly the upper intake is drilled for the EGR ports on SEFI engines.



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[cammeddrz]

^^
so between your comments, and the comments of others. it is safe to say that ultimately there is really no hardware differences between batch and sequntial?

the differences seen are more to do with emissions controls (being drilled for the egr) and using different components on the intake and the heat isolater used in doing so right?

 

[adsm08]

Yeah.

There is no material functional difference. The only existing differences were in the normal running changes that they make to parts to do whatever they trying to do by changing stuff.