rogo7

hello everyone! my first rx and it really flies as long as you don't let it warm up, 'cause as soon as it does the cement trucks can out-accelerate it. Open for suggestions and advice! much thanks

rcksuprstrMX6

First off how many miles? Second have you done a tune up to it? You need to get the plugs out and see what they look like, they can tell you alot of whats going on inside the old boinger. Also a clogged cat can give you bad performance. Whats the exhaust smell like, is it smoking when its warmed? Theres somewhere to start at least, let us know what happens

LongDuck

Hey, as a quick suggestion, I replied to your other thread that you started on this same issue.

If you stick to one thread, we'll all be able to look for you in the mix and hopefully offer up some good suggestions. I'm going to go and dig that one up again and see if you posted a reply - if not, I'll meet you over there. Sound good?

perfect_circle

you must really only know a little, because piston engines are often refered to as boingers, not rotarys. and rotarys, are good wth high mileage, they can go really high. although the clogged cat is a good idea, it is not just rotary info. i mean no insult by this,and im sorry if hat is what is portrayed. you may just be using the term boinger, as a spark plug,i dunno, but just keep in mind, if you continue to call rotaries boingers, some people may not be as forgiving.

rogo7

I've not done computer correspondence like this so please bear with me while I learn the ropes. Thanks for replies, but perhaps it would help if I gave some basics. I am not an auto mechanic, but I am an HVAC technician and have done most of the maintenance on my service van over the years. I have a wide variety of tools but no garage to work in. The car just came to me last week and was used regularly all its life. There is no "bad cat" smell, oil is clean, tuned up by pro last year. Previous owner says this problem started last month out of the blue on a Sunday cruise. Suspect something in emmisions controls or afterburners because it runs so great when cold yet you can barely get it moving when warm. Gotta go, will check in tomorrow. Thanks again.

perfect_circle

vacuum leak? gurus?

FJ

Haven't heard of a bad cat smell, myself. If it's clogged or the "brick" has broken up (cat will rattle when you thump it) you should be able to feel the lack of exhaust with your hand while someone revs the engine. In both cases I don't know if it would be normal for it to restrict only when hot, but I don't see how. The only sure way to check them that I know of is to disconnect it and see, but that's rather loud.

A guess would be the leading coil or ignitor cutting out when hot. It will usually run on trailing alone but barely. Losing trailing doesn't show up nearly as much.
Or the fuel pump, again getting weak when warm.

Is it just slow, or it will barely move?
Can you notice it while revving and stationary, or only under load? If only under load, it might get tricky to find...

Good luck.
-John.

cheapasaurus REX

clutch slipping?

Brianhsval

Mine did the same thing when I got it. Bad coil. Only firing on one rotor. Check it out could be. Bad cat also could be. Mine had one monolith left in it and when it went I couldn't pull a small hill in first gear.

Rotor13B

A bad coil couldn't possibly do this since each coil controls spark for both rotors.

rcksuprstrMX6

WTF does it matter what I call a rotary, you can call it a Wankel motor for all I care, doesnt mean you know a goddamn thing about them, all I was doin was tryin to give the guy a direction to go in, Im a newbie to rotaries but have been building Mazda motors for a few years like the F2, F2t, FE3 2 litre and the BP coded motors with great success. My last 1st gen MX6 was laying down 225 FWHP on a dyno at 18psi, 2.2l SOHC 4 "boinger", not bad for a 14 year old car. My current RX7 sat for 4 years without so much as being turned over or moved and its now my daily driver with no major rebuild work, just some ignition work and a carb rebuild. So dont judge me just by what I refer to a motor as, thats kind of presumptive.

And now back to your thread already in progress....

Brianhsval

I think you better read it again. Bad coil. Firing off of one rotor. Two different sentences. Two diff. problems. The firing off of one rotor was due to the housing seal leaking water.

Yes a clogged cat will kill your power.

DoceA

It's getting a bit tiring to read people's posts where they quickly say something that offends somebody else.
perfect_circle, all you needed to say is: "when we say boinger, it refers to a piston engine" and that's it, not automatically say he doesn't know anything, which would offend 95% of the people on this forum. If you know more then the next guy, just correct them in a respectful, mature manner. Posts should be a way to get help, share information, and learn, not constant bickering.

rogo7

ok - thanks to all for taking the time to try to help with this. I did go out and buy the Haynes manual for the car and have been reading through trying to familiarize myself with all the systems. It certainly raises one's level of respect for a good rotary mechanic. This is one complicated machine, at least on the ignition and emissions side. I'm not interested in bypassing the emissions controls, therefore I must make them all work correctly. So, what coils are recommended and where is the best source for a new cat? Thanks again!

shm21284

check your temp sensor (my first guess), tps, o2 sensor, and mass air flow sensor. if its cold, and runs good, its more than likely just a bad temp sensor

FJ

While your logic makes perfect sense, I only see the "temp sensor" (if indeed you meant the thermosensor and not one of the others) as a possible cause. The TPS and O2 can even be disconnected, and they won't cause his symptoms. While the air temp sensor in the AFM is important, it rarely fails and I doubt it would cause such a severe lack of power.

We were going by what was most likely, given the severity as he described it.
Which is why I asked just how bad it was, and if it only did it under load.

But rogo7 doesn't seem to be too keen to give out details.

rogo7: I wouldn't change anything at the moment as there is no way to know if the cat or coils are the problem, yet.

-John.

YapaKanichi

could he be loosing compression as the car warms up? Just a thought. His ignitor could be shorting do to the heat.

Rotor13B

Well maybe if you would type in complete sentences people could understand you. BTW, that must have been one hell of a leak.

Brianhsval

13b, They were complete sentences divided by a period. As for the water leak, I suppose you have never had to deal with it. Read on and I am sure you will find that I am not the only one who has ever had one run off of one rotor due to this problem.

Instead of trying to cut others who are trying to help, some should spend more time getting into the spirit of helping instead of bashing.

Rotor13B

Your wording leads someone to think that the two were related. You made no mention of a o-ring leak in your housing in your original statement.

Kentetsu

When the car is cold, it will run in what is called an "open loop". This means that the computer and all electronic gizmos are not coming into play. Once the engine is warmed up you move into a "closed loop" condition where the computer takes over.

This would lead me to believe that you have an issue with one of your gizmos that the computer gets information from. Oxygen sensor, mass air flow sensor, and I'm not sure what else is involved. The Haynes manual should be able to walk you through the troubleshooting methods pretty easily, but my first guess would be the oxygen sensor.

Good luck!

lovintha7

Does the mazda FI system rely on a coolant temperature sensor for the E.F.I. like newer cars?

If so, it could be bad, and just dumping fuel in the intake, and flooding it out. Just my $0.02

LongDuck

Lovintha7 may be on the right track, as the SE's do use a water thermosensor on the back of the waterpump to help determine ECU fuel settings during idle-up (warmup).

Something else to look at would be your 'secondary throttles' that are controlled by the thermal pellet (green thing on the rear of the TB). This gets water routed from the back of the waterpump and controls vacuum going to the diaphragm valve just under the TPS to simulate a choked condition. It effectively causes butterfly valves to block off your secondaries, resulting in a rich mixture to help heat up the cats and engine during cold-start. If your diaphragm valve is working opposite from design, it could be getting vacuum when there should be none, resulting in warm running with blocked secondaries - poor power results.

Test this by removing the vacuum line under the TB that goes to the vacuum diaphragm - this will prevent secondary throttle operation and tell you whether it's the vacuum system that's bad. If your problem disappears, start backtracking the thermal pellet to the vacuum source on the 'spider' and then the solenoids that control idle-up conditions.

On the SE's the rat's nest is pretty simple with only 4 solenoids - 2 for BACV operation and 2 for Timing advance vacuum and vent. HTH,

Also of quick note is that the 'closed-loop' EFI mapping only comes into play during steady state cruising. During startup, the mixture is rich due to air flow blockage, not fuel map changes AFAIK.