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semi sequential or batched

Posted: Thu Mar 02, 2017 8:19 am
by K0ENIE
Hi, I'm still working on my Daf Trionic Project and I found an issue witch no-one can answer so I try to use your knowledge :)
The system is full sequential so petrol will be injected on 1-3-4-2 order.
The liquid propane injection (Vialle LPE-4) from the same donorcar is semi-sequential (or half-sequential or batched) so fuel will be injected two times in one cycle.
In this case 2 cylinders are grouped together and on the wiringdiagram I see cylinder 1+2 and 3+4 are grouped.

-------> Should that not be 1+4 and 2+3 ???

http://www.vialleshop.de/skin/frontend/default/theme258k/doc/vialle/Vialle%20LPi%20LPDi/LPiLPdi%20Installation%20manuals/221051.4.pdf
The wiringdiagram can be found on the last page of the PDF.
In the donorcar it was also connected that way.
What's your opinion on this?

Re: semi sequential or batched

Posted: Thu Mar 02, 2017 1:06 pm
by AndreyB
K0ENIE wrote: I see cylinder 1+2 and 3+4 are grouped.

-------> Should that not be 1+4 and 2+3 ???
1) could it be an error on the diagram?
2) technically what is wrong with 1+2/3+4 exactly? one way or another we are squirting fuel on the closed valve, probably does not matter THAT much when exactly.

Re: semi sequential or batched

Posted: Thu Mar 02, 2017 1:22 pm
by Rhinoman
It would be preferable to inject 1&4 and 2&3 to keep fuelling identical between cylinders, it may not make any difference but it could mean that there is uneven fuelling - it will depend on the cam timing. I would hope that its a mistake on the wiring diagram.

The OEM ECUs that I have worked on add fuel enrichment as a second pulse which means that under load they are effectively a batched fired system anyway.

Re: semi sequential or batched

Posted: Thu Mar 02, 2017 10:42 pm
by K0ENIE
Thanks for the answer, it's not only on the diagram, in the donor it was also fitted that way. I think the differents aren't that big but the liquid LPG mixture have different time for damp out and loose temperature on the relative hot manifold. I already ordered a second hand LPE-6 and that one is full-seq.
To be continued!
Koen