A 1984 GS with a 12A. The body is almost perfect and ready to be painted, with just two small holes at the rear wheel wells. It started up fine, gave the obligatory smoke for the first few minutes, then eased off.

So I took it for a drive, and it seemed fine, but slow acceleration from what I had expected. Okay, maybe needs a tune-up.

So then I opened her up on the road a bit. First is fine, second seemed fine, hit 3rd and it would not go over 5000rpms. Kept trying to run her harder, and going up a hill it kept losing power and almost died out on me. Came to a turn, opened her on the flat again, stuttered again at 5000rpm - will not go over that in 3rd gear.

Each time I would come to a stop, she would die as well, but really easy to restart.

I have NO CLUE about rotary engines except what I have read since Sunday. Just wondering if this is indicative of larger problems, or something that might be a simple fix.

I'd run away if the body wasn't in such good shape (reminds me of this one time in college....errr....I digress ) and it wasn't such a cheap price (the car, not the body).

Just looking for info besides getting a compression test done on it.

Thanks, hope it wasn't too horrible of a first post on here.

 

sound like the secondaries are not opening up

 

Welcome to the forum.

Some of the best reading you can do to start with is in the FAQ section.
83rx7boy92 may be dead on the money on this one.
Also need to factor in the fuel filter, it's very common on carb sevens.

 

I had a similar experience today, except I already corrected the secondary problem the day before when the owner dropped it off for some work.

I drove my first automatic RX-7 today. It's a black '84 with overdrive. I think all autos had OD in '84. It was an unusual experience but I quickly got the hang of keeping it from stalling by using both feet to powerbrake it until it warmed up (it needs work).

It had been driven for probably a few years with the emergency return spring activated. The little adjustable nut was gone and the emisions device that attaches with two 10mm bolts was flopping around. I grabbed a nut off of a discarded return spring, installed it and the emissions device and deactivated the emergency return spring. The owner noticed a difference. Then I drove it today and it felt quicker than my automatic Cosmo.

 

Thanks for the welcome.

Would the fuel filter not affect all gears, not just kick in at 5000rmp in third?

And I could rev higher in second and first.

I'll go start looking for info on secondaries so I have enough info to ask questions.

 

Normally no but when in top gear it takes more to keep it rolling so it still may be a possibility.

Here is a link that has pictures so you can identify whether your secondary linkage is hooked up properly.
https://www.rx7club.com/1st-generation-specific-1979-1985-18/common-cause-power-loss-nikki-carbureted-models-632007/

 

Okay, I'll definately check that next time I look at it.

So just to be more descriptive, at 5000rpm there was a loss of power, as opposed to "hitting a wall" and not being able to accelerate over it. Still sound like secondaries?

I'd hate to buy it to find out there's a blown head or something, but I guess a compression test would show that. I was really surprised to find out that my 1980 Mercedes 300SD would run this thing over.

 

Good thing that rotary engines don't have cylinder heads.
All 3 things that have mentioned are a candidate for you driveability issue.

By the way your 300SD is a 5 cylinder Turbo engine. Out of the hole they don't have much but on upper end they can fly.

 

Thanks for the help. I'm pretty good with the Mercedes, and yes, the 617 has enough power to keep her flying up to speed. The nice thing about it is that it accelerates at a nice rate from higher speeds as well as it does on the low end, whether you are starting to accelerate from 70, 80, 90mph, etc.

Back to the secondaries - I'm assuming they are the secondary ports? So looking at the thread you provided, if the secondary ports are opened more for performance, having the throttle linkage adjuster in the "incorrect position" will be okay, whereas a 12a like the one I was dealing with (no secondary porting work done), it will choke the engine out, all the way to a stall at lower speeds.

In a nutshell, basically correct?

 

Secondary ports are on 13B fuel injected vehicles.


The link I gave you is the correct link for carbureted engines. Secondaries refer to the barrels on the carburetor. The 12A is equipped with a 4 barrel carburetor. When the linkage is not hooked up they do not open up therfore the full potential of the carb is not used.

 

Okay, that makes sense.


Now, seeing as I haven't purchased the vehicle, anything else I could check besides the fuel filter, so I don't keep returning to it to check things?

 

Welcome to the forum and the Darkside. Congratulations on your purchase and a well worded 1st post. You have potential.

If the overall acceleration is slow, regardless of which gear, from my experience it's usually a plugged exhaust system, i.e., the cat. It will accelerate easier in the lower gears because it spends less time in them, but once you get to the higher gears, the backpressure has more time to build up and inhibit performance. This is not the only possible cause for the lack of performance though. A partially plugged fuel filter and non-op secondary barrels in the carb are other potentials.

Even if the secondarys aren't opening, eventually the car would reach top speed/rpm, albiet very slowly.

1st things 1st. Do a full tune up and the 30/60k service as listed in the FSM/Owner's manual. There is a thread in the FAQs at the begining of the 1st gen forum titled: 'How to Bring Your RX7 Back to Life' That will cover everything that any new owner should do. Especially if they don't know the maintinance history of thier new 7.

Perform those maintinance items first and see if there is any improvement. Replacing the fuel filter is a must along with adding a can of Seafoam to the fuel tank, (1/8-1/4 full). I also suggest the addition of a 2nd fuel filter between the hardline coming from the firewall to the carb. The supply line is the solid rubber line, the line with the silver check valve midway in between is the return line. The secondary fuel filter will catch any debris that the Seafoam may loosen in the fuel line between the underbody filter and the carb. While you're in there, replace all of the vacuum lines, but be extremely careful if keepimg the rats nest as the plastic nipples on the solenoids snap off quite easily. It's best to use an exacto knife and slice the vac lines length wise on the barbs. If you do break a barb, replacement solenoids can be found in the for sale section. Spray the

If, after the full tune up and fuel filter change, acceleration doesn't improve, check the carb/airpump/acv and thier related components. Pay particular attention to the air tube that goes to the cat. If this is broken/leaking/unhooked, then there's a good chance the cat is plugged. If you suspect this, unbolt the cats and take it for a test drive. Word of caution 1st, the exhaust will be VERY loud. If performance improves, then the main cat is toast, no butter or jam included. Use copious amounts of P B Blaster and let the exhaust nuts/bolts soak fo a couple of days prior to removal. If they are still stubborn, add heat until red hot, acetelyne prefered.

I f you determine that the cats are plugged, you then have the option of spending an outrageous amount of money replacing the cats, or, if you are not subject to emissions, remove the cats and exhaust mani and upgrade to a header system. This is the 1st and best performance upgrade one can do on any rotary.

Post back your results and we can guide you from there.

Ist gens are notorious for rusting out around the rear wheel wells and control arm brackets. Finding one in decent, relatively rust free condition in Canada is getting to be a rare find these days. (I'm presently refurbishing a shell to trailer to Canada for that particular reason.) Address/repair the rust asap and do it correctly. Half-assed/improper repairs will not last long, can cause more damage over time and can easily double the expense it would have cost to do it right the 1st time. The last link in my sig shows some of what I've done on my body.

In my sig line is a link to the online FSMs, carb manual, etc.. Read , download and read some more of whatever you need or peaks your interest.

Btw, newbs are required to post pics of thier new7s. It's an unwritten Man Law, Burt missed that meeting.

 

Don't be afraid to buy this car if it's a good deal. None of the issues you have described lead me to believe that there are any serious issues with this vehicle. Just hit the typical tune up items and get a new fuel filter. If that doesn't take care of it, then you probably just have a vacuum line that fell off somewhere.

Worst case scenario, maybe you need to replace the exhaust system. At least that would come with a healthy performance upgrade as a benefit. How many miles are on it?

As to why the fuel filter would cause the symptoms you describe? Well, between the volume that the filter holds, and what the fuel bowls hold, you can get a good amount of power out of the engine before you run out of fuel (which will typically happen by the time you hit 3rd gear). Power loss at the top end of 3rd gear is ALWAYS related to a bad filter. The stock filter is just barely adequate, and will barely flow enough to keep the motor happy even when brand new. There is a thread on here titled "dual fuel filter mod" that describes how I added a 2nd filter, so that each filter only has to flow at half the normal rate to keep things flowing properly (they share the load). In that thread, there is also a lot of info on aftermarket filter alternatives. Good info if you want to look it up. Good luck, and welcome!

 

forgot my sig line

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I see it there Scott. Have you had enough coffee today.

 

I was going to ask if it was some sort of "Where's Waldo" game or something, but I see it's back there now.

Gotta run out, post back later. Thanks for the warm welcome full of great replies and suggestions.

 

A prankster with the power of a God (or at least that of a moderator). Who will save us now?

 

So haven't bought it yet. Jeep is up for sale, and when I sell it, I will be able to have room for another vehicle.

Wish me luck.

 

It wasn't there when I looked later so I posted it again. Coffee, ah yes, the juice of life and sanity.

 

I have just recently hit this same problem. I replaced the fuel filter already. I haven't done as mentioned above about placing the second filter yet. I do have an exhaust leak though. Car is loud and I can visibly see a hole in the pipe between the motor and the pre silencer. Would this have the effect mentioned above? The same as he mentioned except I can feel the loss of power and then my car starts to violently surge. Feels like I'm in first gear about to stall out and it jerks back and forth, except, I'm usually in 3500+ rpm in third gear. I have a GSL-SE. From what I understand the secondaries are carb related.

 

Post your question in a new thread, and state in the title that the model is an SE. You'll get more help that way...