Lost w/ (assumed) vacuum leak

[Bc-386]

I am now thinking my problem is more electrical than anything else. I test drove the car today, and I shorted out a wire and blew the injector fuse. Got the car back home and found melted areas in the main fuse box and on the wiring harness bracket that goes into the main fuse box. Does anyone know where you can find a diagram that tells you what the wires go to? I look at the service manual but could only find info on the small fuse box that is inside the car (not what I need).

I posted some pictures below.

I feel like I am chasing my tail in circles. This sucks.

 

[hornsfan10609]

I am moving the vac hoses now. I did hook up the map sensor to the port hole from the vtcs removal.

My Vics has been removed as well. I also do not see a purge solenoid. I attached a pic of the connector that believe is supposed to go to the purge solenoid...

Where does the one check valve that was cut shorter need to be hooked up? The nipple on the throttle body, what should be hooked up there? My wastegate is currently routed to it.

Yes that connector in the pic is for the purge solenoid. The hose with the check valve on your car runs to the top nipple (closer to the connector) on the purge solenoid from the canister but it is not supposed to have the check valve on it. The valve goes on the line for the bottom nipple of the purge solenoid and it runs to the vac nipple on the TB firewall side.

 

[Bc-386]

Alright, this might be my problem. A hacked-up wiring harness near the ecu, on the passenger floor board. Who ever did this was a complete dumbass!

I'm not sure what I am going to do. Either try to resplice the wires to their original location or get a new harness.

 

[hornsfan10609]

Check the harness to see if it has been cut/hacked for a piggyback, that is the most likely cause considering the car was modded when you bought it. ECUs do not fail very often on these cars unless you are messing with the wiring.

Alright, this might be my problem. A hacked-up wiring harness near the ecu, on the passenger floor board. Who ever did this was a complete dumbass!

I'm not sure what I am going to do. Either try to resplice the wires to their original location or get a new harness.

Just try to reconnect the wiring as it is supposed to be, it looks bad but it isn't as bad as it seems.

 

[Bc-386]

You were correct about the harness being hacked up.

I am slightly confused on some of the wires slicing/bridging... Is this supposed to be like this? See pic below... I have found a couple wires connected like this. It doesn't look right, but the attaching/bridging wire is surrounding the wire(s) that it is connecting. And that almost looks factoryish.

In the last pick is this plug, looks like this plug is splicing into the wires in the harness. What is this plug and is it supposed to be there? If I could find a clear diagram of this, I would have to bug y'all.

Dang, I'm frustrated. It has been two months since I bought the car and I haven't been able to drive it. Except to autozone for error code scanning and the occasional test spin around the block.

 

[hornsfan10609]

Did the car not run when you bought it? I assume you got it for a good price. There are a couple wires that are spliced into the ECU harness from the factory and it looks like the first pic is one of them. The rest with the plastic crimp connectors are all aftermarket. I'm not sure what that plug is for, likely goes under the dash for the HVAC system or something.
http://www.mazdaspd.com/resources/msppinout1.html

 

[Bc-386]

The car ran good for a about a week. Ha! It has always ran, it just started dying every time I put the car in neutral when come to a stop. Other than that, the motor feels strong.

I feel like I got it for a good price. Might not have been good enough... I know the plastic crimp connectors are aftermarket. But what about the bare metal connectors? It is like there is an insulated wire that surrounds two color coded wires. And the insulated wire is used to bridge/slice into Another wire with the same bare metal crimp. That was the part that almost looked like it came from the factory. After looking at it all, clearly it had a piggy back set up on it.

 

[hornsfan10609]

There was definitely an AFC on that car, it would be easier to install one now since you know which wires to tap. The metal crimp connections are factory, they come wrapped in tape.

 

[Bc-386]

Sweet! I'm so glad to hear that. This won't be too difficult to finish up then when I get home from work. Your diagram of the harness is a lot better than the one i found on the Internet. Thank you

 

[Bc-386]

My new main relay is coming in today so I can button everything up. I went through the whole wiring harness to check everything. I found is ground wire on the passenger side of the car and I don't know where it is supposed to be grounded at. The diagram I found on the Internet just shows that is goes to that side of the car. Anyone know where it is supposed to go or if it matters where I mount it?

 

[hornsfan10609]

It loos like that car has some kind of early aftermarket solid motor mount, possibly AWR. Anyway the ground wire should have a ring terminal on the end and it bolts to the rear most stud on the motor where the mount bolts on. There should be another nut on top and the wire sandwiches in between.

 

[Bc-386]

Thank you so much for your help. I had taken a mental break from the car but back at it. The car has run smoother and smoother with every adjustment for vacuum and electrical. But has not fixed the problem. It still wants to die every time i shift in to neutral (to brake). The problem seemed to be solved while driving to work, but on the way home it wanted to die every time i had to stop in traffic.


View attachment trim.4573D229-B762-43C3-A5D0-441DB05C9D7A.MOVI attached a video of the rpms. I am having to hold the throttle with my foot at "idle" to keep it running. My foot is steady as a rock, yet the rpms are bouncing up and down.

 

[hornsfan10609]

Must be a vac or boost leak, or a clogged EGR or IAC.

 

[tcrawford97]

I had a Honda that did the exact same thing as your vid. it turned out to be the IAC valve. maybe start there and see if that fixes it