So I just finished swapping my blown engine with my engine from my wrecked fd. Everything is connected and ready to go. Starts up fine and holds, but Im pretty sure fuel is dumping from the exhaust. I researched it a bit on the forums, and if it is fuel then its coming from a possible stuck open injector. Im checking that out tomorrow. I also misplaced a driveshaft bolt when getting the transmission to mate with the driveshaft.


I never messed with any of the fuel lines except the three that go into the engine.

I switched between two ecu's, so I know its not that. Anything else I should be looking for or something I was supposed to do and missed?

 

It can be only 1 of 3 things.

First is a stuck open injector like you stated. That's pretty uncommon, though.

Second is a bad injector O-ring. Since they are side feed injectors, fuel flows around the body of the injector and there's an O-ring top and bottom to seal it. If the bottom O-ring is bad, fuel will blow past that O-ring right into the engine, it's too much to combust, and it will come out of the exhaust.

Third, one of the injector wires is damaged and is shorting out to ground. The ECU fires the injectors by pulsing them to ground, if the wire is rubbed through and it's touching a ground, the injector will go wide open.

As I'm sure you know, this is something that needs to be fixed RIGHT and before the car is run or driven any further. This is a SERIOUS fire hazard.

Pull the fuel rails, put in all new fuel injector O-rings, and use jumper wires to test the injectors. You may want to unbolt the fuel rails and pull the rails up then pressurize the fuel system so you can visually see which injector is the culprit.

Dale

 

I wanted more information on using "jumper wires to test the injectors" and found this helpful thread: https://www.rx7club.com/3rd-generati...system-871361/

 

Oh man, thank you. I started off that thread and immediately realized I had crossed two of the fuel lines. Followed them from the back of the car to the front, switched the two and it started up perfect. Turns out it wasnt coming out of my exhaust but spraying from above it where the fuel filter is. I just figured it was my exhaust and that I had a worn gasket.