When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Not that I follow this fully, but Mazda messed with the standard FPR set up by inserting a control solenoid into the vacuum line circuit to help with hot starts.
But in any event, it sounds almost like the OP has an aftermarket FPR installed.
Yeah I have an aftermarket FPR that hasnt ever given me issues. Is there anywhere I can find a complete wiring diagram of the power/ground circuit for the body harness? I have had zero luck trying to find anything like that. Id like to solve this ecu power issue before I go further into the injectors in case this issue is linked to that.
the fpr has nothing to do with this very much electrical issue. disregard that entirely. the wiring diagrams are available in the sticky at the top of this sub forum. you can download them there. this issue is very strange since you ecu has constant power. there is still another problem somewhere since even with constant ecu power, the injectors would not be locked in the open position. this is a good discovery though. moving in the right direction.
there is an ecu fuse in the driver kick panel fuse box. pull it out and see if the ecu turns off. you may get lucky and be able to just pull fuses unrelated to the ecu until it turns off. if its getting constant power from somewhere then it should turn off when whatever circuit its sharing goes offline.... in theory
the fpr has nothing to do with this very much electrical issue. disregard that entirely. the wiring diagrams are available in the sticky at the top of this sub forum. you can download them there. this issue is very strange since you ecu has constant power. there is still another problem somewhere since even with constant ecu power, the injectors would not be locked in the open position. this is a good discovery though. moving in the right direction.
there is an ecu fuse in the driver kick panel fuse box. pull it out and see if the ecu turns off. you may get lucky and be able to just pull fuses unrelated to the ecu until it turns off. if its getting constant power from somewhere then it should turn off when whatever circuit its sharing goes offline.... in theory
Alright, I think Im closing in on a solution. I pulled the main EGI relay and unless im wrong about how this specific relay is wired, then I have a short to ground on the control side of the relay, both terminals inside the junction box had continuity with ground(red circle in pictures {also the relay itself had an open in the coil so it needs to be replaced}). Couldnt upload this with it marked for some reason, but the 2 left connections on the pulled relay both have cont. to ground.
There should not be two grounded pins in the relay socket. See attached diagram showing the EGI relay. It is a typical 4 pin relay, which should only have 1 ground for the signal side.
Alright, I think Im closing in on a solution. I pulled the main EGI relay and unless im wrong about how this specific relay is wired, then I have a short to ground on the control side of the relay, both terminals inside the junction box had continuity with ground(red circle in pictures {also the relay itself had an open in the coil so it needs to be replaced}).
I didnt even realize it at the time, but I figured out why the ecu had a constant short to power. So when I removed the relay casing, the previous owner wedged a folded peice of paper ontop of the relay contact to force the relay to always be outputting 12v (assuming the relay had failed and they didnt want to buy a new one). Thats most likely where my constant ecu power is coming from, but im unsure if the short to ground on the "coil side" of the relay was the cause of the relay failing or something recent and maybe related to the injectors. I will continue to dive throught this circuit. Also I had trouble finding any downloadable diagrams. Not sure if its operator error and mayube I was looking in the wrong sticky thread.
There should not be two grounded pins in the relay socket. See attached diagram showing the EGI relay. It is a typical 4 pin relay, which should only have 1 ground for the signal side.
