Trouble shooting ECU voltage help please!
07-01-20, 12:34 AM
#1
Junior Member
Thread Starter
Trouble shooting ECU voltage help please!
Hello, everyone new/oldmember here hadn’t to make new profile anyway...
I am having start up issues, two of my injectors are getting 12v power on the Rear Primary and the Rear Secondary pins 3C and 3F. I am missing 12v on pins 3E and 3H for Primary Front and Secondary’s Front this iswith the key ON. Measuring at yellow small left connector to ECU. Where else can I check to find out why these two injectors don’t get voltage. Or rather where does power come from before getting to the yellow pin connector. I’ve seen some similar issues in the other threads and they helped me get this far but nothing specific to this.
Thanks!
I am having start up issues, two of my injectors are getting 12v power on the Rear Primary and the Rear Secondary pins 3C and 3F. I am missing 12v on pins 3E and 3H for Primary Front and Secondary’s Front this iswith the key ON. Measuring at yellow small left connector to ECU. Where else can I check to find out why these two injectors don’t get voltage. Or rather where does power come from before getting to the yellow pin connector. I’ve seen some similar issues in the other threads and they helped me get this far but nothing specific to this.
Thanks!
07-01-20, 11:10 AM
#2
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,849
Received 2,609 Likes
on
1,851 Posts
ok the circuit is something like this.
Battery->one of the fuses, in the underhood fusebox-> Main Relay -> injector resistor if its an 86-87.5 car -> injector -> ecu -> ground
since two work and two don't, we can assume everything up to the injector resistor (if equipped) is ok
Battery->one of the fuses, in the underhood fusebox-> Main Relay -> injector resistor if its an 86-87.5 car -> injector -> ecu -> ground
since two work and two don't, we can assume everything up to the injector resistor (if equipped) is ok
07-01-20, 11:08 PM
#3
Junior Member
Thread Starter
Thanks for the speedy reply. So I checked the resistor pack and and it ohm's out normally so after hooking it back up. I seem to have voltage on my injector wires again. However a new problem has risen I am no longer getting spark! I was getting spark the a few days ago but have since noticed my fuel gauge no longer reads the fuel level. I checked the meter fuse under the dash and it is good. The fuel pump is sending fuel. My Leading coil pack and Trailing do not send out spark at all? I am currently reading threw the FSM guide to see if I can resolve my no spark.
07-02-20, 09:25 AM
#4
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,849
Received 2,609 Likes
on
1,851 Posts
spark is CAS->ECU-> coil trigger.
coil power is main relay to coils.. actually the black with white wire is injector and coil power, so maybe the main relay is flakey?
coil power is main relay to coils.. actually the black with white wire is injector and coil power, so maybe the main relay is flakey?
07-02-20, 11:22 AM
#6
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,849
Received 2,609 Likes
on
1,851 Posts
The following users liked this post:
Supergod (07-02-20)
07-02-20, 04:21 PM
#7
Junior Member
Thread Starter
Swapped out main relay have spark again. When key turned to on the Rear secondary clicks but front does not. I’m assuming the same for the primary’s atm. Also now two of the wires broke off the top of fuel pump metal bracket where the black hard circular deals are red and blue wire 🙄. Was trying to reground the pump.
Last edited by Supergod; 07-02-20 at 06:36 PM.
Thread
Thread Starter
Forum
Replies
Last Post
hurleysurf24
3rd Generation Specific (1993-2002)
4
11-08-08 05:51 PM
HIMNI Racing
2nd Generation Specific (1986-1992)
19
05-13-03 08:16 PM