Do a compression test.

My EJ8 had a similar problem. Misfiring really bad. Was about to pull the motor but decided to seaform the engine first. A piece of carbon had wedge itself between a valve and the valve seat, seafoam dislodged it. Now 275,000 kilometers and still going.

 

The car stays on with my foot on the pedal keeping the engine at least 3,000 RPMs but dies if I let off. Even though the car stays on when I'm doing this, the idle is still rough. The scanner was plugged in the whole time. How does keeping the scanner plugged in help? This is my first time using a scanner so that's why I'm asking.

 

Thanks for the response. I'm gonna borrow a gauge and try that out and see what readings I get. Hopefully it's something simple like this.

 

Is your immobilizer light flashing?

 

Have you swapped coil packs yet?

 

No it's not. I actually am using a different ecu from one of my old cars and removed the immobilizer. I've had the ecu in the car since March of 2012.

 

I have tried switching a couple around but I was planning on just switching them out with my friend's. Most likely this weekend I'll try that out.

 

try changing the coil packs.


from what i remembered, they're not cheap either.

 

So yesterday my friend drove his car to my house and I switched over all of his coil packs and ecu. Tried starting the car and still same symptoms...

We also tried starting the car without map sensor connected and without TPS sensor connected just to try it out, same results.

I still haven't done a compression test yet but plan on buying the gauge and testing it out this upcoming Tuesday or Thursday. I read somewhere that it could be the crank position sensor going bad? Anyone else have any other ideas? I also plan on switching in different injectors just to rule those out as well.

 

I had the same issue as you did. It ended up being the injectors. There's a misfire thread on here that's a great place to start.
If you let it run long enough you'll throw code that isn't pending like the 1399. You'll get a code like 0302 0301 0303 0304 the last number telling you which cylinder it is misfiring from.
Here's what i did to fix my misfire issue

I started with the cheaper things. Bought brand new NGK 7772 spark plugs Idled better, but still occasional misfires
changed out the coil packs (drove around for 40 miles with no issues then when I let the car idle waiting for my next class to start it started to misfire again.) Have no idea why only on idle but when i drove the car it was fine

Decided to change out the injectors and it sort of fixed the issue.

mine ended up being a faulty wire harness.... I guess it got messed up somehow, but I did notice that the injector wires had cracked a bit.

You could also do a leak down and compression test to see if you might need some head work done. Hopefully it doesn't come down to this, but if you need any parts I have every one of these for sale lol....

7176442144 give me a call or text if you need help or any parts. i also have an ecu for sale for a 02-03