View Full Version : About siemens deka 630cc

16-08-12, 06:18
hi guys
have any body well experience this injectors with our oem ecu ?

our oem injectors are 384cc at 3bar
we are use it at 2.5 bar = ~350cc (factory setup)
(use this for calc: http://www.rceng.com/technical.aspx )

siemens very big, can we adjust it when idle ?

Im talk with @mpampis
he tell, idle or low powers maybe problem because you use it low limit

Im many time modify Q4 but they are use oem injectors
Q4 injectors run idle 3-3.4ms
I need down this values to ~1.8ms maybe ~1.5ms ?
is it run?

what are you think ?

16-08-12, 06:44
As I remember up to 1.30ms they are working nice. I think the limit is 1.25ms that the engine wasn't start

Steve Webb
16-08-12, 06:56
I've not got any experience of these injectors, but as with most things, once you start using them at the limit of their range they are going to get non-linear in their performance, and the amount of fuel that they actually deliver is not necessarily the amount of fuel that you have calculated.
This could mean that you get a rough idle and jerky running when on small throttle openings.

Do you have a link to a data sheet for the injectors?

16-08-12, 07:34
Im just found this
if its correct, its run minimum 1.5ms


edit for picture size.

Steve Webb
17-08-12, 07:08
Well on that sheet they claim that the injectors work linearly down to a pulse width of 1.5ms so as long as you don't go below that I think you should be fine.

But the diagram they have (linear error / pulse width) does indicate that the injectors seem to be much happier above 3ms pulse width.

18-08-12, 06:23
yes steve

and I think 440cc injectors nice for us

the wombat
18-08-12, 07:15
The pictures look similar to the 3.0 24v 166 CF3 engine injectors.

Not sure if they are, but I have just installed these in my 155 v6 24v. It had the 2.5 24v CF2 engine injectors before that which are a much older design.

Immediatecdifference was the idle was much too rich and caused an ECU error as it ran out if adjustment. ECU errors akso appeared through the rev range, again because of running too rich.

On my car I can adjust this out with the AFM, but it might give an idea of what to expect with the Q4.

I think this would work well with some mapping adjustments.