6 Months ago I purchased an 1984 GSL-SE. Since I have owned the car I have had the following two problem that I could really use the expertise from the members of this forum.

1. When driving down my street (speed limit 25) and I try to maintain 25 mph, the car seems to buck and it looks like I have never driven a stick before. I give it som gas and it smooths out. I try to maintain the speed again and it starts all over.

2. When starting the car (cold) the rpms seem to vary from 500 to 2000 rpms. I kind of revs up then goes back down.

I am learning so much from this site but these two problem are very annoying. I would appreciate any advice, help or links that address these problems.

I thank you in advance.

 

Youd better get used to this and in a hurry or youll wanna get rid of the car (if you do let me know) http://www.nellump.net/peri/epi/firs...gslseIdle.html

 

You've got two things going on; which you've accurately identified as separate (congratulations!).

1) Your Throttle Position Sensor (TPS) needs to be adjusted so that it is sending a good signal for steady-state throttle position. This is simple to do and will require a bit of technical ability to build the proper 'test-rig'. Search on TPS and SE and you should find some good threads dealing with this. The speed that your problem occurs is irrelevant, the fact that it won't maintain steady state throttle without hiccupping is a sign that the ECU is trying to shut down injection when it should only be running it steady - once it starts 'bucking', the ECU is overcompensating which leads to erratic driving.

2) Surging - yep, you've got it, and we've all had it. The quick fix to surging is to remove your air intake pipe and then the Throttle Body (TB). Once you have the TB off, turn it on it's left side and oil all of the throttle rods that move the butterfly valves. Let it sit for 30 minutes, then flip it 180 degrees and oil the other side. This allows the oil to penetrate the aluminum TB housing. The cause of this is that the steel rods have increase friction between the steel rods and aluminum TB housing - also called 'spalling'.

As this friction increases, it prevents smooth movement of the rods in the TB. Since the rods don't turn smoothly, when the engine is cold (and surging is worst when cold), the Bypass Air Control Valve (BACV) attempts to compensate for a low idle, opening the throttle plates a bit, the idle goes up, and the BACV compensates by closing the throttles a bit,... A continuous cycle which results in surging.

Luckily, both items you describe are well-documented and also very easy to fix. Run some searches and then post back here with any questions you have. Good luck,

 

awesome link - thanks steve!

 

Well, I went throught the link you folks provided and after several attemps and a home made TPS light testing kit, I now believe that I have the idle relatively close. I am, however, idling at around 600 rpm and can not seem to get it to go any higher. But compared to the 1800 rpm's I was idling at, it runs smooth. Thank you for all your help and support.

On another note, I tend to think the 1st Gens WILL become classics for two reasons, the most important being that they are rotory engines. THe fact that rotory engines was not a one or two year 'flash in the pan" technology should be enough, the second is the fact that the RX7 is commonly called the Mini-Vette..which should mean something....

Thanks again

 

Actually, most people in the '80s called the Rx-7 the "poor man's porsche"

 

Nice post, longduck. Hell, I don't even have a -SE and feel like I gained something.