okami

So, yesterday I installed a racingbeat header + presilencer onto my fc however, now when I try to start my fc it will shoot up to 3k then drop down to around 1k and then slowly die out. This car is low mileage and I never had an issue with idle before. To put the exhaust on, I took off the AC&CV plus the 5th and 6th ports. However, I reinstalled them with a fresh gasket and reconnected the hoses for them. So, i'm quite lost on what could be the case for this idle issue. If anyone is able to help it would be greatly appreciated!! Thank you

This header https://www.racingbeat.com/RX7-1986-...ers/16130.html
This presilencer https://www.racingbeat.com/RX7-1986-...ers/16405.html
This muffler https://www.enjukuracing.com/product...-rx7-fc3s.html

Jeff76

Not to be a wise "you know" but I would start with the parts you removed. Vacuum leaks, on what you removed or close to parts removed. Hopefully you did the 5th and 6th port cleaning while disassembled. Check for codes if any and verify function of all parts in that area.

I thought that I read on here of a similar problem and a bigger exhaust does affect idle. Maybe not enough back pressure? It would be more likely it is just for the 5th and 6th ports though? I don't recall exactly but I do believe the N/A does't benefit from a larger or better flowing exhaust as much as the turbos. Do people put a different tune on an N/A FC when they do a more open exhaust? I would suspect some do. Do you have the 3,800 rpm hesitation?

Have you emailed Racing Beat? They have decades of experience of people using their parts.

Out of ideas here, maybe just a bump but hopfully this helps gets you sorted.

okami

Alright, so I double checked everything for leaks and it all was good. I go to check the o2 sensor and it turns out my o2 sensor wire wasn't fully connected it was only halfway in I felt so stupid after that one LOL. So, I started the car up now and it idles a bit low like 500ish however, it does idle. A guy I know with a decent amount of rotary experience recommended turning the idle up on the throttle body. Also, about the 3800rpm hesitation I did not experience that when I test drove it earlier after connecting the o2 sensor wire all the way. I felt as though the car revved smoother than before even. So, I'm going to try and adjust idle tomorrow and I'll let you know how it turns out.

Jeff76

Good work finding the O2 sensor. No need to feel stupid, stupid would have been being stubborn or arrogant and refusing to check your work .

I used to build molex harnesses as part of my job, with either pinning them or connecting them to their mate, feel or listen for a click. Even when you feel or hear a click the tabs can break off or not spring back up after the first click, so give them a tug when finished.

Thanks for the update!