'87 RX7 Sport, 100% stock. 116,000 miles, original everything except fuel pump.

When I am coasting in gear and the engine is below 2,000 rpm the engine sounds like crap. It sounds like its only running on one rotor. Also, if it is below 2 or 3k rpm and I barely touch the pedal (less than 5-10% throttle) it sounds like it is only running on 1 rotor. As soon as I press the pedal a little more than 5-10% it instantly goes back to 2 rotors and runs smoothly. The car idles perfectly and runs perfectly all the way from 500 rpm to 8000 when the throttle is >5% or above 2k rpm. Is this normal? It doesn't affect the drivability of the vehicle at all, its just annoying.

 

what fuel pump?
what plugs and how old are they?

 

I have a 86 engine in my bike that I have just swapped out for a rebuild that does exactly the same thing I haven't got to checking it out yet but I'm thinking that maybe the rear rotor is just a tad low on compression , Mine is carb set up but as soon as the throttle is opened a bit it rips hard so I doubt I am starving for fuel . I'm curious to find what people have to tell you . I am going to put a bell housing on it today for the starter and check to see what it has for compression . although it's probably not the problem .

 

I had similar problems. Check the resistance in your TPS. It is easy to do and takes 10 minutes tops. If that doesn't work make sure you are getting proper spark in all four plugs. leading and trailing. Be very careful though I have started fires pulling the plugs and cranking the engine >

 

The fuel pump is a $20 eBay unit, but it provides plenty of fuel up to 8k so I don't know if the pump is to blame. New fuel filter, (haven't gotten a chance to clean the injectors though) brand new plugs (they are the correct brand and part #, I got the set from Adkins Rotary. The car runs exactly the same on any brand of plug though. The car sat for 10-12 years without being touched, and once I got it started it only ran on 1 rotor and barely had enough power to catch 2nd gear, and then all of the sudden maybe a month or two later the 2nd rotor kicked in and it has been perfect ever since. The TPS might be the problem because it got stuck a few months ago and the car went into limp mode. I used WD-40 and it started working again.

 

New oxygen sensor was installed a month or two ago, but it didn't affect the car whatsoever.

 

An 87 rx7 will Not go into limp mode.
only the S5 89-91 will.
If the car was not run for 12 years and improperly stored then I am thinking that is your problem.
You just can't start up one of these engines after a long,unmaintained storage.
You need to take steps.Making sure that the seals are well lubed and "working" before start up.

 

while i wouldn't draw a surefire conclusion on it, i would tend to agree with the 12 year storage certainly being a factor in what's going on with the car.

 

Here's the video of what it was doing when the TPS was stuck, I thought it was some type of limp mode because it ran perfectly and had 100% power until 1500 rpm and then it cut fuel instantly. Can anyone explain what was going on?

Considering how the car was stored for all those years, I think the car is running extremely well, just a few tiny problems to sort out. I think I'll begin with cleaning the injectors and testing the TPS.

 

Try replacing your fuel filter maybe its clogged up.

Also could be a clogged primary injector, bad connection on injector.

Just go thru process of elimination and eventually youll fix the problem.

Rotary >Pistons

 

ngd298, in relation to the video you posted, few months back my car started doing just that when I would start it in the mornings, but it would last only for about 10 minutes until I could rev past 2k and drive fine. Now, it won't keep idle, backfires constantly and very difficult to rev over 3k. What a pain this problem is. You mentioned that your TPS was stuck, how can you tell?