I've been trying to diagnose a problem I've been having and I *may* be on to something...

I can ground the primary injectors @ the ECU and get them to click, however, when I ground the secondaries, no click.... is this normal?

I thought that grounding with secondaries would cause them to click as well. I have power at the each wire going to each secondary injector. I also have continuity from each wire back to the ECU.

I hope I'm getting close...Help!!!

(btw, symptom is that the car boggs down under load between slight vaccume and ~5lbs of boost...between 3500 & 4000 rpms)

 

The symptoms def. sound like secondary injector problems.

I used a small battery to apply 9V between the ECU connector and the injector relay (I can't remember exactly which relay offhand). I did not use the system voltage by grounding at the ECU as you describe.

Dave

 

Firstly mate,, let me ask u did u try pulling the ECU codes ( have u got a standard ECU),,,,because im sure the ECU would pick up that it has a broken connection between ECU and injectors .(i.e broken wire which i beleive is what u are trying to imply)

What u are saying is correct u should be able to ground the secondaries back at the ECU and they should click just like the primaries ( double check to make sure u have the correct wire),,, when u said you got continuity is that from the earth wire from injector to ECU? (if u have continuity from the earth to injector and when u ground this wire the injector dont click that would only leave a faulty injector as the wire isnt broken????)

injector can easily be checked by unplugging the connection and connecting the injector to a battery and earth using a couple of simple wires,,, then tapping the wire on and off power to make the injector click click?

 

First...thanks Dave & Tiger18, I appreciate the assistance...

No codes. I grounded 4W & 4Y (primaries) @ the harness connector to the ECU and heard them "click". I then grounded 4X & 4Z in the same manner...no sound.

As far as continuity I checked the B/Y wire at the injector to the appropriate 4X or 4Z and got .000x resistance. I also checked the ground wires (LG/W & LG) at the iinjector w/ the same 4X & 4Z at the harness. I got similar readings. Now that I write this it has dawned upon me that I probably need to disconnect the injector plug to do this test. Is this correct???

M2 ECU.

Lastly, I sent the injectors to WitchHunter not 2 weeks ago. They are good.

So am I correct in understanding that the EGI relay doesn't interfere with the "ground at the ECU to hear a click" check on the secondary injectors?

Thanks all!

 

Right i have just had a refresh look at the wiring diagram,,,,is a very basic wire setup,,,,all 4 injectors are fed power through a main relay and then remotely triggered to earth by the ECU ( theres no fancy switching circuit or nothing) primaries=== 4W 4Y ( just as u said)
secondaries 4X 4Z,,,, so u are correct with the connectors (please double check this i even used pictures of where the wire was on the connector on the wiring diagram at the ECU end as its very easy to mix stuff up there)
so presuming that we are on the correct terminals,,, i would unplug the injector plug and check for continuity from the plug to the ECU on the earth wire ( if there is no signal the earth wire must be broken),,,,
If you find this,, easy check and fix would be to get 2 lengths of wire and re-run 2 new earths( its either that or unwrap the harness and find the break)

 

I knew I must have screwed up my testing somewhere... I'll unplug the injector & check the continuity of the grounds (to the ECU) this evening. Again, thanks so much for the input!

Wish me luck!

 

you do understand that the ecu supplies the ground to the injectors and varies the pulse width which is the duty cycle. check for power to the injectors. ohm the lg wire from the ecu to injector with it unpluged from both the ecu and the injector. repeat on the lg/w.

if the wiring is ok ohm the injector on the off chance they may be shorted or open

connect a small piece of wire to the injector terminals and connect a 9v battery momentarly to them and see if they click. dont leave it attached to long as holding the solenoind open non stop will heat it up and is a bad idea

if they clik you may have a faulty secondary injector driver in the ecu (asuming the wiring checked out). make sure all the grounds are in place and clean and tight.

that all said it still does not mean that the problem is not ignition related

 

O.k., just finished another round of testing... lg & lg/w wires show connectivity from the injector plug back to the approriate wires at the ECU. 2 things of note:

1) when I applied 12v & ground to the front secondary injector it clicked (as expected), however, it would only click when I supplied power to where the lg/w wire would contact the injector (if the connector were plugged in). When I applied power to the injector pin corresponding to the B/Y wire (and ground to the other pin) nothin. Should it matter which pin is powered up in order to conduct the click test?

2) regardless of which pin I powered/grounded, no click from the rear secondary injector. Normally a slam dunk...bad injector. However, I just got the injectors back from WitchHunter and they all tested good. (btw, resistance across the injector is 13.8 ohms...

Thoughts anyone???

 

you cannot test the injector with a seperate voltage source accurately with the harness on the injector...

disconnect it and repeat it. you would not be the first person to get an injector serviced let them sit for awhile and then have them not work

 

I'm betting the injectors were damaged during cleaning or they are sticky/stuck from the cleaning solution. BTW I have some nice low mileage used ones from a 2001 jspec hehe

 

Sounds stuck to me.
This may sound crude, take a small hammer or rachet handle and smack the injector with it.
After injectors are flow tested, the pintles can stick if they are not installed and run immedeately in gasoline. You can knock them loose with mechanical shock. There is a device called an injector pulser that can put a little more juice (safely) to start it too.

joe Geiman
Gasoline Alley Fuel Injection

 

Doubtful that they were damaged from the cleaning since I personally flow test each injector and take test data before shipping. It is possible that one is stuck, although it is rare for it to happen in such a short time after servicing. A light lube is put in them before shipping. As mentioned, a light tap on it will normally free it up if it is stuck.
We will be glad to check and retest it if needed.

Gordon
WitchHunter Performance

 

Well after doing a bit more talking (thanks Gordon among others) and testing it's clear that one of the secondaries is not firing. Lucky me it's the rear injector... I took the plugs off and supplied B+ & ground to the pins while monitoring fuel pressure in the lines. Sure enough the front injector clicked and fired fuel. The rear injector did not click and as a result no drop in fuel pressure.

I have to admit this is more than a little disappointing as I had the symptoms of a bad secondary, took the time to remove all the necessary stuff to get the injectors out. Sent 'em for testing & cleaning. Reinstalled days later (btw, they checked out good before & after), still had the same symptoms. This caused me to have to back-out of my first time trial in quite a few years. Also caused a bunch of wasted time trying to figure-out the problem..."obviously it can't be the injectors as they have been tested as good..."

Anyhow, hope to have a chance to pull the guilty bugger out this weekend and give it a love tap to see if that helps things. In the meantime during the testing process, my rear rotor has decided to stop firing. Haven't spent the time to diagnose, hopefully the that injector is stuck open and is flooding the chamber.

Joy!