No Injector Pulse on Cyl #2

[jtreign9097]

I HAVE A 94 Q45.. new coil pack and plug and new injector. i tested it on diff cylinder...it works fine... i have injector pulse on all cylinders to verify my home made tester works.... the wire on connector to cyl #2 red/green.. i followed it back to a 8 prong connector on passenger side next to the knock sensors connector.. i cleaned the connection and even bypassed just that wire it to see if would get pulse in case there was a bad wire/connection i couldn't see.. but still no pulse/ground
were can i find this wire going into the car? i would like to test it at the source... if anyone knows the pin # on ecu or a have diagram that shows injector #2 from ecu? car runs great but 7 cylinders is not fun.

[jtreign9097]

Ok so i seen injector #2 goes to PIN 106 on the ecu... i ended up finding alot of strange splices in the harness non factory near the main ecu connector.. not sure if this is stock but it was electric tape on some wires.... maybe someone ran new wires at one time? i'm going to attempt to run the injector wire directly to the injector to bypass any possible break after the fire wall if there is any.. so basically ecu directly to the injector... or i may just check pulse at the wire itself on pin 106 to verify the ecu is ok..... its only ground so ill use a led noid light to see pulse.. doesn't anyone know if this is common thing for ecu's to quit pulse on one injector?. but like i said i see splices that make zero sense.... . and i did try to wide open injector by ground it for a second and it works just needs the ecu's correct timing..... i did this with it disconnected from wire harness so ecu wasnt involved..

[Q451990]

:Welcome: to NICO! I'm guessing you're looking at the factory service manual if you're pointing out ECU pin numbers - but if not, they're available at www.infinitiservicemanual.com

I "think" I remember Q45Tech mentioning a bad ECU with this type of failure once, but it's very rare. It sounds like you know what you're doing with the testing - so just be sure heed the warnings in the FSM about not testing through the ECU's ground terminal.

[jtreign9097]

I "think" I remember Q45Tech mentioning a bad ECU with this type of failure once, but it's very rare. It sounds like you know what you're doing with the testing - so just be sure heed the warnings in the FSM about not testing through the ECU's ground terminal.[/quote]

i took ecu apart found a huge spider net and water corrosion on the pins on the bottom corner.. cleaned it up and no more misfire or engine lights.. but when i run diagnostic mode i get code 51 34 21 16... now i know 34 is knock sensor.. and other codes may have been caused by me unplugging things but i don't have any current engine light on so were these codes old stored ones?... also now that its running smooth now rpm is rough all the way to 2,000rom and a miss at 1500 rpm... basically a a lot of hesitation until 3000 then it smooths over... should i try cleaning the maf over and over or is this an IAC issue typically with this car? i know in many other cars the tps is what can cause this but not sure they go bad on these cars commonly.. Car does has 209,000 miles and i didn't get a code for it