On my '85 GSL SE (13B injected) I have a strange reving problem. The car when coming to a stop will automatically rev the engine to 2,800 rpm, then rev between 2,800 - 3,000rpm. It is actually quite funny, but I am sure it is not normal. Any clues to what the problem might be? AIC?

Mike

 

The car does not perform this way all the time, only sometimes. It normally idles fine between 900 - 1400 rpm (which might be high).

Mike

 

Thermostat maybe? When my car is cold it idles about 2000, but once it warms up it drops. And if your idle is high allready, that might be added to the high rev anyway. At least your idle goes high, and doesn't go low like mine does. When I stop it will drop down to like 150-200 then rev back up to about 800-1000 and hold.

I could maybe see that your car isn't differentiating between it being cold and hot if there is a probably with the thermostat or something, but other than that, I have no clue.

 

The car only exhibits this bizarre behavior when it is warm. Plus, it does not hold the same rpm while it "revs" itself. The reving does not happen all the time? It is really interesting.

On any given day it changes it's idle rpm whether warm or cold (from about 900rpm or 1,400rpm).

Mike

 

my old SE used to do that but very rarely
it seemed like it only would happen after driving it for an hour or more
never figured it out, my friend wrecked it

 

I too have this problem, it is especially funny when you are at a stop light next to a ricer. This morning i had a jetta behind who got all fired up and did the ricer fly by.

One thing that helps is to make sure you get on the gas and give her hell for a couple runs. My 7 seems to hurt for the idle if i have been taking it easy and the car is slow to warm up.

If you find the solution reply back, becuz this is definitely an ongoing problem with the GSL-SE.

 

At least I'm not the only one. LoL!

I literaly sounds like some form of launch control.

Somebody has had to of fixed this issue?

Mike

 

Weird, thats how I solve my idle surge when sitting at a stoplight too, after I take off I give it hell for a minute, and it will stop. It's almost like its flooding or something and trying to burn off excess gas, or something.

 

I'm a bit rusty at this but I used to be a shade-tree Rx-7 mechanic through college. I've had two 1st gen's sitting in the driveway for years but a cream puff GSL-SE got me back into action again recently.

At first light, it sounds like your throttle position solenoid (TPS) might need adjustment (fuel injection only). There's an electrical gadget that you can plug into a particular empty plug on your harness and you adjust the lever that triggers the TPS sensor (little black plastic sensor on the front side of the throttle body) until it's solidly made when the thottle is released. It's pretty touchy and while it's not a frequent adjustment, it can cause the symptom you are describing....and be erratic because sometimes it will be made properly (especially if you lift off the throttle rapidly after a hard acceleration).

 

Sounds like the classic common problem of the throttle plates not closing all the way. Lube up the shafts that the butterfly plates attach to and you should be fine.

 

Thanks,

I will try lubricating the throttle plate/butter-fly shafts first. I would not be surprised if the TPS was out of adjustment though. We will see?

Mike

 

RX7ROX is right on with this one.

Look up 'SE Surging' in search and you'll have a bunch of threads from me and others on how to fix this. It's most prevalent when the overnight evening temps drop and the throttle body rods start sticking. Take off your air pipe from the AFM with those two chromed 12mm cap-nuts, and spray some good silicone lube or similar onto both sides of the Primary and Secondary throttle body rods (that hold the butterfly valves).

I guarantee that this will fix it. No need to 'hotrod' to fix the problem (you're not even really fixing it), and your car will appreciate it,

 

Thats not the problem at all!
Your computers integral "Honda sensor" has fallen out of calibration due to all the riced up domestics being found on todays roads. Mazda makes a new "rice sensor" which covers all tastelessly modified vehicles on the road today, including spinner equipped vehicles. Just ask your local mazda parts counter!

 

Thanks Longduck,

My info was passed on to me from my dad who was the second owner of my 7. He asked a Mazda mechanic years ago about the surging idle and the mechanic passed on the "give her hell" advice. My dad also never knew the 7 has a LSD rear end. And now he wants it back after I did all this work getting it up and going again. haha

 

you guys need to take after us carb'd 7's and get a return spring LOL