RotaryEvolution

iTrader: (30)

this may also be useful in helping some people diagnose injector issues although for my purpose is a bit different.

using spare engine harnesses, ECU and some sensors i am trying to set up an injector test rig with the bare minimum in order to get the injectors to begin firing.

so far on the harness/ECU i have the following:

N326/332 S4 non turbo/turbo ECU(trying both)
crank angle sensor(1T to Ne1, 1Q to Ne2, 1P to G2, 1N to G1)
all grounds tied together( pins 3A, 3G, 2R and 2C)
pins 3E, F, H and L to injector leads
12volt source to opposite injector leads as well as pins 3B(start signal, may be removed at a later time to control the duty cycle) and 3J(12v input)

so far nothing, i planned on installing an airflow meter to see if the lack of signal in conjunction with other misc missing sensors was cutting the signal but so far the extremely simplified system isn't responsive.

there is no resistor pack but it shouldn't be necessary, at least not for the 332 ECU yet neither give results just yet.

trying to get this setup to check for leakdown, balancing and possibly for future modification to do cleaning and servicing with. in a city with 1.5 million people you would think there might be more supply for injector servicing stations... only found one, a diesel shop which gives no result sheet and questionable work via a car that stumbles lean while smelling like a gas station with everything else setup, double and triple checked(leaned out via the VR).

yes i have used RC and witchhunter in the past but i a) prefer to see results myself and b) it wastes yet more time working around dead vehicles waiting weeks for parts to return.

satch

iTrader: (1)

You forgot pin 3I from the Main Relay which powers up the ECU so that pin needs to see 12 volts as well.

RotaryEvolution

iTrader: (30)

i overlooked the 3I circuit which comes from the main relay, FSM doesn't show that as an input or output so i left it off without thinking about it.

primary injectors cycle properly now.

thanks Satch, might have saved me about an hour if i checked back sooner(granted half that time i was running a complete harness versus the simplified one to plug in various things).


so that is the bare minimum, including 12volts to pin 3I to get your injectors pulsing with the CAS. literally 0 sensors, no airflow meter, variable resistor, nada. that will get you into the basic startup pulse width amount that the ECU sends flat out.

satch

iTrader: (1)

This is good to know since there was always some confusion as to what role the AFM played relative to firing the injectors. Now you need to find out what is the bare minimum necessary to fire the leading coil. Just a thought, but it's probably the very same set up for the injectors.

RotaryEvolution

iTrader: (30)

most likely, i did plug in the AFM and removed the pin 3B wire and could audibly hear the injectors tone change when holding the door wide open versus closed. will do some playing around with it a little bit later.

BUT

i could swear i could hear the same change with the 3B plugged in as well with the AFM wide open versus closed. seems they both still read off the AFM but the base may be much lower with 3B disconnected.

ah well, not going to guess until i get the pressurized system setup and some measuring devices as well as the drive gear.

i'll pull up the diagram for the coil outputs and see if i can get a signal reading.

satch

iTrader: (1)

When the ECU does not read the signal on pin 3B the ECU will defer to the AFM to select how much fuel is used to start the car instead of selecting from one of the two internal ECU base maps and this amount is much less than what the ECU would choose from. In this case the sound would likely be more subdued then if the ECU did receive the start signal at pin 3B.

j9fd3s

iTrader: (3)

neat project! there are lots of things to play with, but you could also hook up the start pin on the ECU, and then it should be in the start map, which should only run from the CAS and coolant temp.

oh also this is maybe very obvious, but you probably don't want to hook up the actual coils/wires/plugs, LED's or something might be a better solution than having high voltage sparks on the bench

RotaryEvolution

iTrader: (30)

lol, no fuel setup yet so you won't get rid of me that easily!

i plan on just wiring up one of each type of injector connector to each lead so it will be pretty simple to set everything up without killing myself. probably will also look into different solutions for the testing versus gasoline. as far as the setup goes, i really could care less if it is getting spark or not, but it would be nice to know if it is putting it out for diagnostic purposes.

satch

iTrader: (1)

If you were to test for spark you could use the leading coil in one of your cars and thus would only need to connect two wires to this coil. One wire would be the battery voltage wire while the other would run to pin 1V of the ECU.

RotaryEvolution

iTrader: (30)

hooked pin 1V up to the pink wire off the trailing coil, 12v to the tan wire and grounded the case. getting spark to the leadings just fine as well with no sensors hooked up on the simplified system.

satch

iTrader: (1)

Thanks for the info and the effort put forth.

RotaryEvolution

iTrader: (30)

no problem

there is also other things to consider, i have noticed that having a faulty AFM plugged in caused the injectors to not fire on another vehicle so there is some things that can actually prevent certain things. unplugging and replugging that AFM back in would cure that issue temporarily. i figured that one out as the car would start with the AFM unplugged but not if i tried to turn the key from off with the AFM plugged in. still having issues with that car in fact and partially why i'm setting this up. i tried several AFMs but the issue persists with poor running, poor fuel consumption and poor performance.