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Weird misfire

1224 Views 3 Replies 2 Participants Last post by  stamps31757
Okay, I know I may get flamed for this and I did do a search but I didn't find anything that was quite what is happening to me.

My original engine (KA24DE) took a dump on me, so I bought another one with 105k miles on it. We swapped it in and started it and had a miss in the number 4 cylinder. So we changed the injectors and fuel rail, still had a miss. Changed the plugs, still a miss. Then we changed the wires, and it was fixed.
I drove it around for a day, then parked it. Went back to drive it the next day, turned the key, and now I have a miss in the number 2 cylinder. We changed the crank sensor (or I think that's what it is) and the rotor and cap, it didn't fix the problem. And for some reason the miss will come and go. It'll be missing when I start it, drive it a few feet, and it will clear up (sometimes). Now if I park to go inside a store or when I'm at home and come out like an hour or so later, it's missing again. I don't understand why it would just do it sometimes and be fine the next.

Would anyone have any idea of what's going on?
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you might have a short somewhere between the ecu and your spark plugs. Coming from wrx's that missfire all the time. There are alot of things that can cause one. i noticed that you are on the right track though. have you changed any of the injectors. sometimes that causes it. the most common cause that i have seen is plug wires not properly plugged in. keep us updated.
I was thinking that it's either the fuel pump or injector, I never would have thought about a short. We will check that next, especially since just one injector is $100. Would the ECU throw a code if it were a short? Thanks man!
i don't think it will throw a code for a short but with a multimeter you will be able to see if you are getting they right current and voltage. take a look at your injector harness and see if it is damaged. After you have ruled everything out as far as electrical you can then start replacing the small things that might be the cause.
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