TBONE690072

Injectors 1-4-6-7 not firing. Can anybody tell me why or what to do? I'm bout ready to burn this sob down!
Thanks

BUP

iTrader: (9)

U have 2 injector banks 1 4 6 7 and the other is 2 3 5 8

you could have a bad ground(s) and or a bad driver in the ECM.

possible have the ECM checked out.

Also year model and engine serial # helps as well especially for checking all SB's for that serial number runs.

articfriends

iTrader: (1)

Ign powers. All of them all the time, ecu gounds 4 of them at a time, probe the power supply to them for 12 volts

TBONE690072

Boat is a 1990 concord 007 engine 502 mag efi/mp. Had 454 carb and got 502 and had hell ever since.

TBONE690072

Would you know where I could get the ECM checked out?
ThAnks

articfriends

iTrader: (1)

So if you gently pierce the power wire to one of the injectors that are not firing with a VOM meter or even just unhook it from injector and start it you will see immediately if it has power, no power then its just a matter of going backwards thru the harness. IF it does have power find the pin on the harness to ecu that grounds those 4 injectors and see if you have continuity at the j connector to ecu, I would do that before I started worrying about the ecu, would take you like 20 minutes with a 10$ elcectrical meter, fwiw

TBONE690072

Well it's it has power it has ground I took one of the injectors off that was working and it does flash when cranking but the there's no flash on 1-4-6-7.

articfriends

iTrader: (1)

So take it a step further, see if the non firing injectors have 12 vdc, going from power supply pin on harness at injector to a good ground on motor, the 12vdc is present all the time when running/cranking, it might even be present when ign is just in run position, dont remeber for sure., the ground comes from ecu as it fires the injectors, once you determine which one is missing you will be able to narrow down the problem. The fact it doesnt flash tells us what we already know, that one of the two is missing, trying to help. IF you have 12 volts all the tim its cranking then we now the ground is missing, find what color the ground side of the injector pigtail is, find that same wire in j connector at ecu and test it with a ohmeter for a good circuit

TBONE690072

Ok I'll check it out and get back to you.
Thank you for your help. I may need some more.