SR20DET Running Lean/ Limp Mode?

[Kingtal0n]

I had this exact problem with a wiring specialties harness. One of the pins that contacted the coilpack output (At the ecu plug) was only making contact sometimes. We tracked it down by individually twisting each coilpack output wire until the symptom appeared.

To fix it, at least temporarily, I shoved some bits of wire into the plug to make the contact patch "larger".

otherwise, it does sound like an ECU related issue. If you cannot cause the problem by twisting and pulling the wiring harness around, you should try a new ecu. Always keep a spare 62/E5 handy. heck, even I have one, and I dont even have an s13 sr20 anymore.



Here is some food for thought,
The wideband is telling you more than you realize. If a coilpack output failed, the wideband would read lean, it would pick up the oxygen leftover (unreacted) by the misfire.
So, misfires cause lean readings- yours is a rich reading? You need to describe the problem better. If the engine "sounds like it is missing" but the wideband is reading rich, again that points back to the ecu/maf/leaks....


Another possibility is that your "BOV" is getting stuck open and leaking to the atmosphere. That would also cause this same problem. Try plugging the BOV with a sock or tape or something to eliminate it as a possibility.

[BroDude240]

Originally Posted by Kingtal0n

I had this exact problem with a wiring specialties harness. One of the pins that contacted the coilpack output (At the ecu plug) was only making contact sometimes. We tracked it down by individually twisting each coilpack output wire until the symptom appeared.

To fix it, at least temporarily, I shoved some bits of wire into the plug to make the contact patch "larger".

otherwise, it does sound like an ECU related issue. If you cannot cause the problem by twisting and pulling the wiring harness around, you should try a new ecu. Always keep a spare 62/E5 handy. heck, even I have one, and I dont even have an s13 sr20 anymore.



Here is some food for thought,
The wideband is telling you more than you realize. If a coilpack output failed, the wideband would read lean, it would pick up the oxygen leftover (unreacted) by the misfire.
So, misfires cause lean readings- yours is a rich reading? You need to describe the problem better. If the engine "sounds like it is missing" but the wideband is reading rich, again that points back to the ecu/maf/leaks....


Another possibility is that your "BOV" is getting stuck open and leaking to the atmosphere. That would also cause this same problem. Try plugging the BOV with a sock or tape or something to eliminate it as a possibility.

I failed to mention when I ordered the harness, I ordered the wrong MAF connector (Z32) and the wrong injector connector (Bosh, EV1) so the guy's at the shop had to cut those and put the correct ones in. The injector ports have already been replaced twice and don't have any excessive resistance. Same with the MAF connector.

Good point. I guess it sounds like it's misfiring but it is running 10:1. It sounds like I have a heavy cam but my idle is fine. The ECU shows a solid red light and buzzes when the car is turned off. When you try to drive the car, it sputters hard over 2,500 RPS unless you floor it. After running like that for a few minutes it will die when put into neutral. I have a video on my phone but no way to upload here. This problem occurs at completely random times.

I'll give the BOV thing a shot tomorrow.

Is my A/F ratio fine like they say it is or am I running a risk driving it like that? Could an ECU cause a bad A/F ratio?

Thank you for the reply by the way.