So I recently bought this 7 and I'm trying to work out a few bugs. This is my first rotary car so bare with me because I'm definitely a noob. The car surges at idle and it won't hold a steady rpm above 2000. Please check out the link below. So far I've changed the oil and coolant, adjusted the tps, adjusted the dashpot, cleaned all the grounds, and replaced the battery and plugs. The car has a old xs engineering turbo kit with a pfc. No idea who tuned this car. The seller knew next to nothing about the vehicle. I plan to get it tuned but for now I just need to get it running properly. Any ideas?

https://youtu.be/neVWrf3IXiU

 

Any ideas at all?

 

Have you checked for vacuum leaks? If so, how.

 

I did test for leaks by pressurizing a vacuum line to 3psi with my compressor. Found one big one and fixed it. Maybe I should try another method?

 

One vacuum line is not necessarily connected to the rest. A visual inspection and tracing the lines against the color coded diagram would be a good way to start. You're definitely pulling good vacuum at idle, though.

You could also have a throttle body that has been set up improperly for some reason. Is there tension on the throttle cable? Are the butterfly valves nearly closing and coming to a rest before the cable stops moving? There is some good info on the throttle body in the yahoo PFC tuning group as well as in this post: https://www.rx7club.com/3rd-generati...tments-866062/

 

Check all the Vacuum lines...if that's not it

If you have a dataloggit save the tune on your computer then reset the PowerFC. Try to run it on the base map at that point. My FD acted like that once and it was the tps. All the values checked out on it but when I swept the sensor(watched the voltage sweep), it was jumping all over the place and wasn't linear. I had never seen it before. As suggested, the other thing to check is the Throttle body, our throttle bodys don't like be adjusted. I'd check all that again as well.

 

I will give the vacuum lines a thorough inspection then move onto checking the throttle body. If that doesn't work I'll move onto running the base map. I just checked the sweep on the tps and its definitely linear. Thanks for the suggestions. I will report back when I get a chance to work on the car again

 

My car had the same symptom of dropping it's rev at about 2k; among many other problems. I shot the TPS with a multimeter and although it ran up pretty linear it was missing a voltage when closed. Changed it just because, and adjusted the Idle as a whole following this thread:

https://www.rx7club.com/3rd-generati...g-more-170731/

The procedure this guy lists is for Power FCs I guess. Naturally Stock ECUs require the use of the FSM to adjust the idle. Either way there's a TON of good info in the thread. Not sure what it was that fixed the problem for me because I had done so much at once, but it was related to the throttle body for sure.

Also, arghx dropped a line on this write-up of his: https://www.rx7club.com/3rd-generati...needed-841706/

I haven't read through it completely just yet, as I have yet to install my power FC but i'm sure there's some useful info in there as well.

Good Luck.