So I finished my ka24de swap awhile back, and have been working out some minor bugs here and there. I'm just now able to use the car as a daily driver, and upon filling the gas tank for the first time since picking it up in Spokane, the idle went rough, it started missing,stuttering, and wanting to die.
So, one thing at a time I start replacing stuff. Fuel filter, plugs, cap and rotor, Blaster coil I had laying around, cleaned the MAF, ran cleaner through the injectors. By the time I had used up about a half tank of fuel doing test drives, it was purring like a kitten.
Yesterday, I fill the tank again, and it runs like shit again. Any ideas? How the hell can the level of fuel in the tank affect how the car runs??

the gas in the tank on that last fillup was probably bad.

Run the shit empty a few times and I bet it goes away.

Nah that doesn't make sense that it runs perfect under 1/2 tank and like shit above 1/2 after two consecutive fills. A mechanic my gf works with says it's probably an evaporative loss hose getting fuel in it when it's above a certain level, allowing raw gasoline into the intake and trying to flood the engine. This makes better sense and would explain why I smell gas instead of oil when I remove the oil filler cap.

figured i'd give the thoughts on it, cause we had similar issues with Garrett's ka24 car when he drove up through wisconsin in 07. his fuel filter and injectors were clogged up to shit. thats why I threw that out there.

+1. sounds like a stuck purge valve, or something in the tank that is allowing the fuel to get pulled into the engine.

Purge valve? Where might I find this and make it pay? By the way, I fueled up on sunday, kept it below 1/2 tank, continued to run like a champ. Added 2 more gallons, started running shitty

not sure. nissan may not even call it a purge valve (why, i dont know). i'll see if i cant find it at work today on mitchell. someone w/ an FSM could look too.

the only thing i found that could be like a purge valve is the EGR/Canister control solenoid. Per mitchell on demand, it is near the rear side of the head, close to the firewall, maybe down a bit.

a picture i found on zilvia.net...



BTW, i looked up the operation of the SCV (Swirl Control Valve). It has a passage in each intake runner, and during idle/low speed operations, it close to increase the air velocity, and swirling effect of the intake air. doing such promotes better combustion via better fuel atomization.