Hey! I am an owner of a 1987 Mazda RX-7. It had been sitting in my uncle's backyard for about 4 years until I brought to my house. However, after breaking my brain, I am not able to make it hold its idle. It turns and starts up, then it will go to about 2500 RPM then slowly goes down to about 1000 RPM then dies. I changed the MAF and I checked the TPS and it seems to be working fine. I adjusted the TPS as well to no available. Can someone please help? I am completely new to working on Rx-7's and I have no idea what my next step should be.

 

4 years is a long time, maybe bad fuel pump ??

Mine also doesn't hold idle when starting cold. I just manually hold throttle between 1k-3k rpm until the engine warms up enough, then it holds to 1k by itself after a minute or two, then runs like a dream warm. Is yours like that?

 

honestly I haven’t tested it like that. Something else to try. I’ll let you know how it goes. Thanks!

 

JonTheT,

welcome to the club. First thing you're going to want to do is to download the factory manual for your car. It can be found at Foxed.ca. These manuals are fairly detailed and should help you navigate troubleshooting. Give them a read before you start poking around, and then if you have any questions, let us know. They have the troubleshooting procedures laid out, and are pretty much the same as what we would tell you to do as far as basic stuff goes.

 

Mine is stored a lot, as are most of my cars/trucks.
Perhaps you've already done these kinds of things,...but when my '88 began to act this way in cold weather (and it acted exactly as you describe), I simply installed new spark plugs, and it starts and warms up as it should,...! I was nearly shocked with the difference!
Anyway, just a thought, since I saw such a difference in a stored RX-7,...
Best of luck with your 'new-to-you' car!

 

Hey guys! Thanks for all the support. I checked the fuel pump and it seems to be working fine and im able to keep it running as long as i have my foot down on the accelerator. What i have noticed is that when it reaches about 4000 RPMs it ends up sputtering for a little bit but continues on. What do you think might be the problem in this instance? Would you think it might be the TPS?

 

Awesome ! Does it hold idle by itself after you let it warm up a bit?

Seems like there are a few threads about the 4k rpm hesitation, looks like there's some good info in here:
https://www.rx7club.com/2nd-generati...-power-757645/

and from the FAQ:
I have this hesitation whenever I accelerate right around 3500-4000 RPM
The dreaded 3800 RPM hesitation is cause 90% of the time by poor ground connections between the engine, the battery, and the car. Clean or replace all the under hood ground connections. On 86 model year cars , replacing/regrounding the pressure sensor's ground wire has helped (do not re-ground a 87 or later model year). If there is still a problem after that, look at cleaning the fuel injectors and (on a N/A) that your 5th/6th ports are operating correctly.

 

It still does not hold idle by itself after the car warms up

 

Hm definitely try replacing the spark plugs as wetminkey suggested (or at least pull them and make sure they're on right, trailing/leading etc), check the air filter too and see if it's clogged or dity. Other guesses are clogged injectors or a vacuum leak somewhere.

 

Hey guys! I was able to find the problem! the BAC was clogged with carbon buildup so I cleaned it our with some carburetor cleaner and it worked like a charm!