tbouler

I don't want to incur the wrath of everyone who has already posted to the 'car is slow' threads, but here is my problem. I have an 84 GSL. I have owned it since 87, it has 56,000 miles on it (yes, it sat with limited mileage for a few years while it had 'issues'). It is my wife's car, she won't get anything else, she loves her "Luidy Belle".

Within the last few years I replaced the coils, distrubutor, wires, replace plugs about once a year, new starter, igniter wires (I actually don't remember the specific name of those dam... darn things but they are tiny wires on the side near the coils), basically all new electricals. I have a new fuel filter, will try to put that on tomorrow. But here is the problem. My wife told me the car was just not getting power. She was driving at max around 45 mph. I replaced the plugs, took it for a test ride, and she was right! It took a long time to get to 60, and then only with the passing gear kicking in multiple times (it is an automatic). I thought it might just be that she isn't 'driving' the car, so I tried to keep up the aggressive taunting to get it to go faster. Well, while approaching a turn that had a 35 mph sign, the throttle stuck, even braking didn't disengage it. Finally it disengaged about a mile later, but was slow to decrease RPMs. I made it home, after finding my religion and praying that the car would make it home before she decided to do the opposite and give herself no gas (yes, I am personifying Luidy Belle, but she is a remarkable woman!). I have taken her to two places, including the dealership, with no avail as to what the problem is. The first place had a mechanic that had an RX-7 at one time, and he thought it might be the fuel pump, filter, carburator (12A engine), or I had a compression problem. Also he and another had a fight on whether the 12A had a throttle body sensor or not, which I did find somewhere that it does, and he found it did too, and thought it might also be that. The dealership found that the trailing coil's wire was arching on the distributor cap and, of course, recommended to replace the wires, plugs (the brand new ones), and the distributor. I bought wires and a new distrubutor cap. As I said, I will replace the fuel filter, wires, and cap tomorrow. But, there is more!!

I also noticed that there is a puff sound coming from the catylitic converter. Not always, but it sounds like she is backfiring, or having a problem with the exhaust. I am going to see if the above changes take care of that, but it has always had that noise intermittently, not as frequent as it is now, but I just had not tried to find it before.

Now for the questions: Would a faulty fuel filter cause the throttle to stick? My wife doesn't want that adventure on her everyday commute! Also, any ideas on the puffs and what might be causing it? The exhaust system is still the original from 83 (she was made in September of 83). Any thoughts on the power problems also?

I'll post what happens when I replace the fuel filter and wires. If that takes care of the problem, then nevermind!

Tucker

kgray

look at the color of the cat after its been running for a while. Red hot? Many people have had this problem and the new or aftermarket piece solved the problem.

Kentetsu

Verify that you are getting spark on your leading ignition. Sounds like a clogged cat could also be the issue, but spark is easier to check so do that first...

85rotarypower

I was reading your post, and as soon as I saw mention to the exhaust sounding strange I immediately thought clogged cat. Its actually not all that hard to see if thats the problem. Basically, unbolt the exhaust at the flange just in front of the catalytic converter and take it for a SHORT ride. I suggest you wear earplugs as it will be VERY loud, but if the car acts like normal again then its most likely a clogged cat. Thats the only way to really check for a problem with the cats. Just looking at them to see a colour change is just not good enough IMO. There is a lot of heat there, but not nessesarily enough to make the cat look "red hot".

tbouler

Thanks! I've been working all morning, haven't had time to play yet! Should get back to the car this afternoon. I was under the car yesterday and thought the cat might be a problem too. Could that be a contributor to the performance problem as well?

85rotarypower

If the cat happens to be clogged, that most likely is the problem, not just a contributor. If the exhaust is plugged up the engine has a hard time pushing the exhaust gasses out and it will severely hurt performance. Unfortunately its not a cheap fix. A new set of cats for a 1st gen runs around $2000, mabey more. Aftermarket cats can go for $300, but there is a greater chance of clogging them and there is really no guarantee that it will pass emissions testing with an aftermarket one.

farnoush

**** is it really 2 grand for the new stock cats? If the cats the problem i would just get some catco ones off of summit, they're only like 50 bucks.

linexrandy

Hack the cat's!!! I did, course i dont have emmision's test either!

rbf41182gt

If you don't have emissions testing, then just replace it with the racing beat presilencer.

SevenHeaven

It could be a combinatin of problems. I've had my 85 GSL for 10 years and it often gets stored long term as well. A clogged cat is a good possiblity its a common issue. Also check the ignitors (the 2 little black boxes on the distributors).

Clean and lube the carb. These carbs are notorious for gumming up and sticking. The carb may look clean but quite often the fuel will varnish the carb and the secondaries will not open reducing power and possibly the opposite, holding the throttle open. Using gas with 10% alcohol content helps keep the carb clean and rotaries run better on it too. Premixing a high quality 2 cycle oil with the fuel also helps alot too. I know of one Mazda dealer who cleans the carb of any old school RX-7 that comes in for routine service because they can gum up so quick.

Make sure you are using high quality wires and plugs. NGK was the OEM supplier and in my opinion the best for this car. I have never had an issue with NGK plugs and wires in these cars.

Also check the condition of the cap and rotor and the distributor for damage. High quality cap and rotor go a long way in these cars too.

These cars were not cheap when new and were not excatly cheap to maintain properly. High quality parts are not cheap but I have always spent the extra coin and in the long run they pay off because they don't give problems.

One last thing, check the fuel pump. Not a common failure but a possiblity! Good luck!

tbouler

As I thought, the wires and filter didn't help. In fact the car is a little rougher running now. I think the fuel pump is going. I ran it down the road at 60 and it started to drop power and I could hear it not running consistent. Could be the cat only, but I think I'll order a fuel pump and cat, just to be safe.

BTW, there was 'junk' in the fuel that came from the old filter. It looked like rust, but I'm not sure. It was solid. Could be that I have more problems than just the cat.

trochoid

iTrader: (6)

Sure can. If the filter is catching crap from the tank, the S3 tanks have a drain plug. Mazda recommends draining the tank annually as part of it's standard service regimen.

If the stuff in the filter is rust particles, aussiesmg suggested placing a strong magnet by the drain plug, driving the car around, then draining the tank. The S3's tanks have a filter screen, internally, on the pickup tube. They often split/fail, then the external fuel filter plugs up. You may need to change the fuel filter more often and carry a spare, they are cheap for the carbed engines.

Kentetsu

Search up a thread called "dual fuel filter mod". There is a bunch of info on aftermarket filters that have higher capacities than stock. If you have gas tank/rust issues then you might want to consider this option. Other than that, listen to Dr. Trochoid and you can't go wrong...

Whanrow

Aint that the truth! Plus, now having said that, we can really have fun with him when we catch him in a mistake!

Back to the subject at hand. In order of ease of checking I think I'd do the following:

Check to make sure leading isn't connected to trailing and vice versa (now that a couple of different people have played with the car)

Fuel system as mentioned above

Check cat

Could even be all 3 things combined....

Rx-7Doctor

iTrader: (13)

The 1st thing i recommend after checking to make sure you have fire on the leading side.
Is to do a compression test. Now it's possible as everyone has stated that it could be the converter.
or a combination of problems as stated. Also verify that the secondary linkage on the carb has not come off. But even that will not stop it from going above 45mph.

trochoid

iTrader: (6)

LOL.

You guys have to quit raising this pedistal higher and higher that you put me on. It hurts more each time I get caught and fall off.

tbouler

Thanks guys! Next for me is to check the leading and trailing sparks, disconnect the first mono from the manifold and see if that takes care of the power problem (if so, then I'm replacing the complete exhaust system from manifold to muffler), and check on the aftermarket filters. Fun times to be had here!!

I really appreciate the help, as does my wife. She loves her Luidy Belle!