FI Volume test.

Carbs & F.I.

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Jivermo
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Re: FI Volume test.

Post by Jivermo » Thu Jan 31, 2013 7:17 am

I hope to do the volume test this weekend. I have two pumps, and I'll try both of them and post the results.

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SlowLane
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Re: FI Volume test.

Post by SlowLane » Thu Jan 31, 2013 10:08 am

Reid wrote:Maybe a water cooled Vanagon had bank fired injectors instead of our batch fired injectors? The engineers could have been trying to minimize a pulse on the other bank, I guess.
I'm unable to determine from a brief perusal of Bentley whether that is the case or not. There doesn't appear to be any input to the ECU which would inform it which bank is ready to fire (ie. camshaft position sensor or distributor-driven trigger), so my gut feeling is that they still used a batch-fire scheme. Anyone with a WBX know for sure?
'81 Canadian Westfalia (2.0L, manual), now Californiated

"They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance."
- Terry Pratchett

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dingo
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Re: FI Volume test.

Post by dingo » Thu Jan 31, 2013 10:59 am

"two pulses occur for each working cycle regardless of the number of cyclinders. For each turn of the crankshaft,each injection valve injects once, regardless of the position of the intake valves "
'71 Kombi, 1600 dp

';78 Tranzporter 2L

" Fill what's empty, empty what's full, and scratch where it itches."

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Amskeptic
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Re: FI Volume test.

Post by Amskeptic » Thu Jan 31, 2013 2:38 pm

dingo wrote:"two pulses occur for each working cycle regardless of the number of cylinders. For each turn of the crankshaft,each injection valve injects once, regardless of the position of the intake valves "
Where did you get that quote?

I am of the mind that Digifant is a "simultaneous single fire" with half quantity per pulse.
Colin (corrected -just now)
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

Reid
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Re: FI Volume test.

Post by Reid » Thu Jan 31, 2013 2:52 pm

They are fired together. I just looked at a wiring diagram.

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dingo
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Re: FI Volume test.

Post by dingo » Thu Jan 31, 2013 6:14 pm

Gasoline Fuel-Injected System L-Jetronic

(Robert Bosch GmbH Stuttgart 1995)

..very good reading and great diagrams and charts
'71 Kombi, 1600 dp

';78 Tranzporter 2L

" Fill what's empty, empty what's full, and scratch where it itches."

luftvagon
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Re: FI Volume test.

Post by luftvagon » Mon Feb 25, 2013 9:44 am

Reid wrote:They are fired together. I just looked at a wiring diagram.
Within the L-Jetronic operation all 4 injectors open and close at the same time. All 4 injectors are opened and closed twice every 720 degrees; or 1 full engine cycle -- 4 strokes. The signal to open the injectors is triggered by falling edge from the negative side of coil

Image

and then signal goes through a process to be shaped, divided and to calculate the exact opening interval based on auxiliary inputs: TSII, TSI, AFM. These 3 inputs will "append" additional time to the base injector open time.

Another interesting read is the L-Jetronic patent:
http://www.google.com/patents/US4481928 ... ms&f=false
1981 Volkswagen Vanagon Westfalia - air-cooled Type4 1970cc CV (hydraulic lifters, 42x36 valves, stock cam, microSquirt FI with wasted spark ignition)
1993 Ford F-250 XL LWB Extended Cab 7.3L IDI

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SlowLane
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Re: FI Volume test.

Post by SlowLane » Mon Feb 25, 2013 11:24 pm

luftvagon wrote:
Another interesting read is the L-Jetronic patent:
http://www.google.com/patents/US4481928 ... ms&f=false
Oh my, yes. Especially the bit about calculating the "sucking-off coefficient". :bounce: Who sez that Toyotas aren't sexy?
'81 Canadian Westfalia (2.0L, manual), now Californiated

"They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance."
- Terry Pratchett

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Amskeptic
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Re: FI Volume test.

Post by Amskeptic » Tue Feb 26, 2013 9:01 pm

SlowLane wrote:
luftvagon wrote:
Another interesting read is the L-Jetronic patent:
http://www.google.com/patents/US4481928 ... ms&f=false
Oh my, yes. Especially the bit about calculating the "sucking-off coefficient". :bounce: Who sez that Toyotas aren't sexy?
Toyotas!
L-Jetronic was All German in the beginning, didn't Nippondenso sort of imitate Bosch to the point that they just bought rights to re-brand?
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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SlowLane
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Re: FI Volume test.

Post by SlowLane » Tue Feb 26, 2013 11:30 pm

Amskeptic wrote:
SlowLane wrote:
Oh my, yes. Especially the bit about calculating the "sucking-off coefficient". :bounce: Who sez that Toyotas aren't sexy?
Toyotas!
L-Jetronic was All German in the beginning, didn't Nippondenso sort of imitate Bosch to the point that they just bought rights to re-brand?
Could be. The Toyota patent referred to by luftvagen's link clearly shows that they were trying to put their own personal mark on the "L-Jetronic style" of fuel injection, in this case by smoothing out the effects of AFM vane overshoot during sharp acceleration.

I bet that Bosch didn't mind by then, because they would already have been well into development of the hot-wire MAF sensor which eventually supplanted the AFM. As far as they were concerned, Toyota et. al. could dick around with workarounds for the AFM all they wanted, while still paying Bosch the licensing fees for it. :wink:
'81 Canadian Westfalia (2.0L, manual), now Californiated

"They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance."
- Terry Pratchett

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Amskeptic
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Re: FI Volume test.

Post by Amskeptic » Wed Feb 27, 2013 4:09 pm

SlowLane wrote:
The Toyota patent referred to by luftvagen's link clearly shows that they were trying to put their own personal mark on the "L-Jetronic style" of fuel injection, in this case by smoothing out the effects of AFM vane overshoot during sharp acceleration.
Seeing as the vane overshoot is the "accelerator pump", no wonder the pig BMW 630CSi could spank a Datsun 280Z.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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