JDM 3rd Gen 3SGTE Closed Loop Lean Misfire / Poor Idle, Engine Goes to Closed Loop EFI, it Coughs, Stumbles, and Misfires Options

[J3rkyBoy]

About 6-8 months ago, I installed an EBC solenoid for the already-wired in Greddy ProFec B Spec II in my ST205 front clip conversion (JDM 3SGTE, 3rd Gen, stock ECU) 1996 GT. During the week I had it in, it developed a misfire at idle (and a sputtering cutout between 2800-3100 RPM). The misfire appears to be as soon as it switches into closed-loop EFI mode and is as dramatic as someone flipping a switch: one second it is fine, and the next: cough, sputter, choke and AFR usually around 16-18 from 14.7. It is usually worse the hotter the engine is. It seems to be intermittent and can go a day or two without issue. As soon as I step on the gas and get it north of 3k it is typically fine and I'm good.

Please advise.

Aaron

[J3rkyBoy]

I want to say thank you to all you guys who responded. I had an illness in the family and duty called. Please accept my apologies for this late reply.

Okay.

Well, with every forum post, one has to balance the length of their post and its provision of sufficient facts to let others make the assessments we seek. No doubt, we have all asked questions, received answers, and rebutted with facts not known to the responder at the time of their response. This is one of those replies.

To Slavie, the original responder (and fellow 6GC'er, who said via PM "post this to the forum") I say: I do believe you are on to something. All I have available to me at the moment is my multitester. I do know it is not the correct tool, but in this case, it is better than nothing and, I believe, shows something interesting. I uploaded a video to YouTube and am posting the link. Please take a look if you have the time.

To Bitter: man, all I have in my possession is my trusty multitester. I know it ain't the right tool, but I think I do see something odd in its reading. If you might also check out the YouTube video I published, I would appreciate it. Maybe there is something of a clue.

To Consynx: Stock turbo for JDM ST205, so, CT26? The EBC solenoid is not the issue right now (unless it damaged something and this is the outcome) as I removed it after a week, as soon as the misfire started. Plugs have been changed ... twice. Good to hear someone had a positive experience with a slipping clutch; mine always meant money, and pulling the engine (which I just did two months ago).

To Enderswift: resistor has been gone since before this started. 12v constantly (and yet I still find the strength to go on ... listening to my Walbro sing at full-tilt boogie whenever the engine is running ... by simply opening my exhaust cut-out and punching the gas! ;-) ). One of the first things I checked was fuel pressure consistency. It appears to be within spec (BGB). One oddity regarding fuel pressure: when I physically touch the rubber fuel line after the fuel filter on its way to fuel rail, I can feel a definite hard "clicking" type pulse to it. If I had to describe it, it would be, like, someone smacking the line 5 times per second with a pencil, or a screwdriver. Listening to it with an automotive stethoscope yielded a definite, loud, clicking/metallic smacking sound ... existing only in the fuel hose. Have no clue. I would ask you as well to please watch this YouTube video and see if it provides any clue.

And now, since I spent so much time on my computer without charging it, I have to get going to my home so I can charge it again and provide new information/hopefully read a reply which knows why my O2 sensor is spiking to 2-3 volts as my engine stumbles and goes lean. I realize this video is boring, so just say so and I will post either a link to me almost wiping out in my Celica in Ohio on the way back from NJ to Seattle, a link to me giving the business to a Lamborghini Gallardo who decided to flex on me for no reason, or, and this one is probably the most interesting and funny, what happened when a hot girl came up to me and said "I'll su** your di** for a ride" last year ... just sayin' ;-)

Thank you all for your replies. I need them.

A@ron

https://youtu.be/aafZE3G5oV4