Akkmednoseflem

Hey guys, I have a KW s/c on my 04 s2000. I have deatchswerks 1300cc injectors, walbro 255 FP, AEM v1 and NGK iridium plugs gapped at .22

All started Saturday morning, was driving home and car felt great. Was a little low on fuel (e85) but instead of going to fill up, I went home (lazy) About 2 hours later I went to start it up and go put some gas. Started up and immediately idled bad. AFR went super lean and sounded like a Subaru. I thought maybe it was because I was low on e85, so I limped it to the gas station, it stalled out on me 4 times. Put a full tank of e85, made no difference.
I can hear the fuel pump priming, and can hear the injectors clicking.
Pulled the new plugs that were installed a week ago and they were white. Also pulled the injectors to clean off some gunk, and ran power through them to make sure they are spraying. Cleaned the Air idle control valve and did a compression test on the motor.
I let it idle with the MAP sensor disconnected and the afr went to rich instead of lean?
My question is, what could be causing this issue? Is there a way to test a fuel pump? Could my ignition coils be the culprit or my injectors?? My tuner isn't able to look at the tune for a while.... although I don't think its a tuning problem.

Thanks for any insight

AP1Chief

Send me your tune and log jmpaintcorrection@yahoo.com

i can see if I can see anything causing it

CoolGuy094

"Sounding like a Subaru" usually means a single cylinder misfire. I'd start unplugging coils to see if you can find the cylinder that its misfiring on. Then start swapping components cylinder-to-cylinder to see if you can determine what component might be causing it (coil, injector, plug).

afzan

There have been some cases of the aem v1 (maybe v2 also) causing premature coil failures. I'd check there first, you can try unplugging one at a time like cool guy suggested or just swap all 4 with a s2000 buddy

Akkmednoseflem

I swapped coils with a set from my brothers car, made no difference. @AP1Chief, I don't have a laptop or anyway to get my tune to you Still waiting on my tuner to get back to me. In the meantime, I pulled my fuel pump today, in hopes that it was a bad filter but everything looks good. Could my EMS be toast??

Soul Coughing

Identify the cylinder that is misfiring. Pull coil plug, or injector plug, one at a time until the motor doesn't change noise or RPM. Once you've identified the cylinder that's misfiring, you can then work out what is failing. I've had a few coil packs fail on me, but i've also had the coil driver on my AEM EMS go bad too. If you said that injectors, coils and there's no big issue with low compression, then it's more than likely the AEM coil driver that's gone bad.

s2000Junky

Bad coil/spark would make the plugs look black/sooty, not white from running lean. Would also show as a rich afr. Something is up with the tune or fuel system on the car causing it to run lean. OP said all new plugs were white. That confirms the lean afr seen on gauge.

riceball777

Sounding like a Subaru means your engine is running on 3 cylinders. Most likely you have a bad coil pack.

EOE

In my case it was a bad injector and I was running on 3 cylinders. She sounded mean, but no power. ha

s2000Junky

Anyone can say its sounds like a Subaru but that doesn't pinpoint a fuel or ignition problem, so I look at all the available information presented and deduce best form there rather then basing off someone's interpretation of a sound. In this case, again a bad coil pack/no spark means the plug gets fouled- doesn't fire= wet or black plug and will also show a rich afr. Its not a coil pack if the OP checked all the plugs and they were white plus is seeing a lean afr on gauge.

It could be an injector like EOE said, which is part of the fuel system. But if the OP said all the plugs are white, that would likely eliminate a bad injector, unless they all decided to miraculously go bad at the same time. Running E85, its more possible with a clog pre injector? Its still more likely that the fuel pump has gone bad, or something in the fuel tuning changed.

So first order of things to check is starting at the source/ the fuel pump and work your way forward. If the fuel pump is verified to be delivering proper fuel at idle, then it may be worth checking the tune at that point before processing further along the fuel system. That's what I would do.