boost_is_best

zczc


Modified by boost_is_best at 10:48 PM 7/9/2007

Soccerking3000

peak and hold, or low impedence, high impedence/saturated can be plug and play for obd-1 cars

tractionlimited

peak and hold injectors, also called low impedance, are initially fired at around 4-6 amps, through a ballast resister, and then fall back to 1-2 amps for the rest of the injection event. this injector is often used on high fuel pressure systems where the increased initial amperage overcomes the high hydrostatic pressures of the fuel pressure. they tend to respond faster than saturated injectors, and are more stable at higher fuel flow rates.

saturated injectors are the new style of injectors that almost all automotive companies have been using from 92-on, mostly because they are simple, inexpensive, and reliable. these injectors work by having the ecu supply a +12v charge to each individual injector, the injector opening when it receives the charge and closing when the ecu stops sending 12v. the downside is that they are slower to respond than peak and hold, and can decrease the usable operating range of the injector, especially when the fuel system is under high pressures

hondata's site has a good diagram of how the 2 different styles of injectors are wired. the top represents the saturated style whereas the bottom diagram is for peak and hold. with my setup i'm using 450cc peak and hold injectors from a dsm, i got a 91 crx hf resistor box (which came stock with peak and hold injectors) to wire them in.

TOP=SATURATED
BOTTOM=PEAK AND HOLD




***edit***
with peak and hold injectors, the ecu goes low to fire each individual injector, grounding all of them and using the +12V signal coming from the ecu to create a potential difference in the current and therefore fire the injector.

basically, with this style setup, full voltage is being applied to an injector to raise the pintle, then reduced in order to hold the pintle up for the remainder of the pulse width.

thanks to EE_Chris for catching that, i totally forgot to mention that. EE_Chris, i assume the EE stands for the engineering subfield, am i right? I'm a 1st year ME over at Tenn. Tech University.


Modified by tractionlimited at 6:44 PM 2/28/2006

EE_Chris

The ECU uses a ground to turn the injectors on. The rest of your info is spot on though.

RogueWorks

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boost_is_best &raquo;</TD></TR><TR><TD CLASS="quote">hey i was woundering for witch injectors do i not need a resitor box, peak and hold, or satrurated?</TD></TR></TABLE>

Try these?



Not trying to be a jerk, sorry, just could not resist.

2muchboost2blow

bump, edited my original post under my new screen name, damn honda tech trial user status

rorik

how does a resistor in series with a fixed load and voltage drop result in a varying amperage draw? In other words, why would the amperage start out at 4 and then drop to less than 1 once the injector is open? The injector's resistance does not increase once it is open.

I believe a True peak and hold injector driver does not have a fixed resistance in series with the injectors. It is a much more complex circuit than that.