So I just rebuilt my rx7 and did a lot of emissions delete stuff (basically everything) and it runs but sporadically has a weird misfire issue right at 2.5k rpm where it seems fuel starved. It doesn’t happen 100% of the time but it does often. I can’t figure out what it is and the car was even having almost this same issue before I rebuilt it. Here’s a video of me driving it:
What should I check first? Anyone had a similar thing happen to them before? There a lot of details abt what I’ve done to the car and what I’ve removed/replaced/kept so lmk if more info would be helpful. Thanks

 

I would check for codes first.

 

How do I do that on an s4? Do they have some type of OBD1 system?

 

http://2ndgenrx7.freeservers.com/error%20codes.html

You will have some false positives with so much removed.

I am not sure of the symptoms of a clogged cat, it might be worth looking into, though.

 

I made a test light with two led’s as described but had no codes show up/blink.

It doesn’t have a cat, racing beat full exhaust with the pre-silencer replaced with a straight section of pipe.

 

Nice work making the lights!

The one thing that everyone should do is refresh all of your grounds.

https://www.aaroncake.net/RX-7/grounding.htm

I am kind of confused? You probably took out the BAC and no codes. I accidentally left the atmospheric pressure sensor disconnected once and mine definitely caught it.

Have you set your TPS? Or checked CAS and other connector/wiring for corrosion? I was surprised that the spark plug on these cars don't hold up very long, wires probably way longer.

 

Thanks for the link that looks really useful, I’ll definitely make sure to check all my grounds.

Yeah basically every emission component is deleted including the BAC. When I plugged in the lights and turned the key to on all that happened was they both turned on for a few seconds and then off again. I waited for like 30sec or so and got no blinking.

I’ve tried to set the tps but it left me a bit confused because since mines the s4 the tps is narrow range and only give a reading for 1/4 of the throttle travel. I set the tps to read 1k ohms at idle but idk how to set it at WOT because it just stops giving a reading since it’s not in contact with the lever anymore.

The CAS connector definitely looked corroded but I cut it and hardwired it for testing purposes and has good continuity all the way to the ecu plug. I’ll be picking up a little connected to solder in after work today though bc having it hardwired is not a permanent solution.