i didnt know the accelerated cold start was bad for the engine..

 

It's not.

 

By the same argument you are using to "negate" our unhealthy cold start throry, you cannot make the claim that it is not damaging. There is nothing in the FSM that refers to the AWS function as an neccesary engine preserving device.

 

Since a few of you guys are jumping all over me to "prove it", I'll say the same. You have zero proof that the AWS doesn't cause more wear than a normal warmup idle, so please keep the authoritative comments out.

I said it above, and I'll say it again. I don't buy your carbon theory one bit. I've never used AWS in over 30k miles. I've never flooded the car once, even after shutting it down when dead cold. My motor had very little carbon build-up when torn down at 85k, despite the fact that I had a primary injector leaking and low compression. Driving this car in a normal fashion with the fuel/ignition/tuning in good shape will keep the engine from carboning up. Driving with problems or like a grandma may not.

I'll bet that just about any rotary tuner in the land will say not to use the AWS. In any case, you have your opinion (and that's all it is, not a fact), and I have mine. Start your car up at 3k rpm all you want. The rest of us will move on with the Power FC or other standalone (none of which support AWS) and enjoy a smoother running car with better gas mileage and power.

 

I don't recall the RX-8 having an AWS. Anyone know for certain?

 

True just the same that know one can claim that it's a really bad thing either. For years pretty much everyone has thought this was a bad feature but yet no one has stepped up to prove otherwise. I'm just trying to give my opinion from a differant perspective.

Here's something to think about. Search this forum and try to find as many threads about bearing failer. Then search for threads about compression loss. I bet you will a crap load more threads on the compression loss.

Oh yea! Mazda has used this feature for about 20 years now. That's a long *** time to be using something that doesn't work.

 

I wished I could search. All I get are proxy error messages.

 

This thing has gotten a little silly. The marginal damage, if any, done to these motors from a 5 or 10 second 3,000 rpm burst at cold start-up pales in comparison to everything else that causes rebuilds.

Really trivia. I still have it on my car and I will keep it on my car for as long as I have the factory ecu, just like I still have the double throttle and sequential twin turbos. The factory computer expects to find it there and there it will be. No factory ecu I would probably dump it.

In any event, the guy who started this thread feels better when his car jumps up to 3,000 rpm and wants it fixed.

 

LONG:

Great! I don't expect everyone to agree with me. My theory is based on my many years of ownership of rotary powered vehicles. Since 1991, I've owned an 81,84,91 & 94 Rx7. Does this make me any expert? No! However I do have a ton of ownership and maintenance experiance. Also having owned some of these other engines gives me a reference point to compare to my data. That gives me an advantage in general knowledge about these engines compared to others. You would be suprised the differant things you learn while owning differant generations of these engines.


Example: My 81,84 & 91 Vert have all flooded at one point or another. My fd has never done this.

My 81 lasted 151K and failed because of a leaking radiator. I broke this engine down and you wouldn't believe all the carbon that was inside. This engine flooded often.

The 84 failed at 140k, This one had carbon lock. The plugs stayed in a little to long (30k) and it sat up for 3 months without being started. I went to turn it over and it locked down. This car never had any coolant problems but it did flood on some occasions.

Given my previous ownership experiance of these two cars, I made sure that the 91 vert would last a long time. Maintenance was spot on. Oil changed every 3k. Plugs & fuel filter changed every year or 12k. Coolant flushed evey 2 years and distilled water added to keep corrosion down. Hell I even flushed out the brake and clutch fluids. This engine never had any leaks what so ever. Guess what this engine only lasted 140k. It also flooded on me a couple times. I was like WTF! The rear rotor has 0 compression. I took care of this engine to well for this to happen.

This recent failer forced me to look back at my driving habits. All these cars were driven and shifted at 3k or less. Very rarely would these engines ever see the upper rpm's. This would easily explain my flooding and carbon lock issues because of all the carbon build-up inside these engines. I bet you that any tuner would tell that my driving is what cause the majority of my problems. They will also tell you that these engines need to be reved and run hard often. Why? To keep carbon build-up as low as possible.

This brings me to my Fd. I still drive the car too conservatively(by habit). I still shift at 3k or less. My maintenance of this vehicle is excellent. With 94k original miles on the clock, I can go ouside right now and fire it up, quicky shut it down and then restart the car and it will never flood on me like the others. So why does this car not flood like the other 3? Simple, my driving habits did change with this car plus I've learned (through this forum) how to keep the carbon build-up down. This engine will occasionaly see the upper rpm range. Even thought it's my dailey driver I still shift at 3k, however when I do get on it, I can see a ton of black smoke exiting the exhaust through my rear view mirror. Thats carbon burning off. I also use water and a vacuum line to de-carbonize the engine every six months.

Lastly, if anyone wants their engine to last a really long time, keep the carbon build-up down as low as possible. This is why I like the AWS feature. It natually allows the excess fuel to burn off during a cold start which will keep carbon build-up down. I believe the majority of carbon is built during the warm-up and low rpm stages.


Like I said before, you've tracked your car on occasions. So odviously your driving habits are much differant from mine. You gave your engine the opportunity to burn off the carbon like I didn't. That's why my engines had so much build-up. If you drove your car like I did you would have the same problems that I did.

 

Very well said! Thats why I say that the AWS feature isn't a bad thing.

 

I owned a 79 for four years before owning my current 95. The 79 never flooded on me either. I stupidly sold it with 175k on the motor, running fine when I let her go.

I fail to understand your driving habits. Why would you put up with all the crap of owning these cars and never enjoy them? My engine would most likely have made it at least another 10k miles on it, but I wanted to tear it down for a fresh start. That's at least 95k miles, a lot of it being driven like it was meant to be.

Again, I fail to understand how you can own an FD and rarely take it above 3k rpm....the real fun with these cars starts at 5k rpm. Live a little, man.

 

I bet you never shifted at 3k like I did on this car either. Our differances in our individual driving habits will make a big differance in this comparison.

Thats the thing. These forums didn't exist during my ownership of the 2 1st gens. I never really knew what these engines were capable of. All I knew was that I really liked how differant they were. It wasn't untill when the 3rd gens came out that I really fell in love with these cars. Thats when I started to realize what my 81 Rx7 was all about. I didn't know anything about Mazda's race history or the victory of the 787b. So I started to research the history of these engines. Oh by the way, my Fd has been far more reliable than any of the other Rx7's I've owned. That reliability differance is probably why I drive it the way that I do.


Hey what can I say? With full coverage, I have really good insurance rates. Driving responsibly is a natural habit for mine. I don't even street race. However, the Fd does get a decent beating every now and then. There is a 2 mile stretch of highway near my house with no traffic that I can take my car out to so I can open it up some. Trust me she does every bit the 160mph. Will I ever go that fast again......... HELL NO!

 

Wow 5 pages completely unrelated to the question at hand. What a waste of my time.

 

My AWS only works when it's very cold outside... now with the summer heat it rarely works, only on very chilly mornings

Maybe this has to do with the original question

 

Actually, if I could add a question real quick in this whole mess, I always start in 1st gear because of the AWS, in the mornings, but in the afternoon when I leave work, I don't have to, because the engine stops at 1500, almost acting like it's flooded, and then settles down..... thoughts?

 

Your car's probably warm enough that the AWS doesn't kick in. Afternoons in California are pretty warm this time of year.

-s-

 

Your clutch switch may be stuck (just a thought)... if someone else posted this already, ignore me, i didnt wanna read 5 pages lol

 

I just fixed the same problem......There is a small seneor just under the alternator
that gives you that 3ooo rpm start up . check for cracked wire or conector to this sensor
the sensor is called ( water thermo sensor )

 

For first few weeks I had my FD, I would let it do the usual 3000k rev. I did not enjoy hearing it rev like that anymore so I started to just (1) hold clutch in (2) shift to 1st (3) crank. The way I see it, it's like pooring cold water on someone sleeping...they wake up in shock and get all antsy! Just turn on the lights (using steps above) and the person will wake up regularly.

On side note....since I have a GReddy elbow, the AWS hole isn't present like a stocker elbow. I can't be leaving my AWS hose opened without a filter at least so I placed a filter cap on it...will try to disable it later probably eventally.

 

yea, im sure your right, thats what I thought as well, just wasnt 100%, plus with it acting like it was flooded, strange.... thanx man

 

Nice contribution to the thread.

Anyways, I've been letting the car warm-up with the 3 start activated. No problems. If you can't get it fixed I would just hold the throttle for a little while.

 

Theres nothign wrong with it.

 

personally i love the aws, probably for dumb reasons.

1) mazda does it for a reason
2) i get a back fire when it finishes
3) when i slow city drive alot... next day when the aws kicked in i'll get a light stream, with small puff at the back fires of black smoke, then never happens again.

so personally i believe as t-von said. it's a "way" to help keep carbon buildup down. but hey, if it's there. i'll use it. like like since the turbo's are there. i'll use them too. i daily my fd everyday. but lately since it's aug in houston and even the morning are humid and warm. my aws hasn't kicked in lately. it'll rev only to about 2-2.5K then dump back to normal... then again i'm having my gauge cluster shortage still. so i'll see how it goes.

my .02


Los

 

I couldn't contribute anything because I'm having the same problem. Consider every related response after mine as part of my contribution thanks to my bump that brought it back to the top.

By the way, it looks like the AWS system is as simple as the temp sensor opening a valve for 30 seconds on startup. So, I guess either the temp sender (I think its the coolant one on the back of the filler housing) isnt sending the signal (either because its malfunctioning or too warm), or the bypass valve isn't opening.

In my case, I believe that one or more of my injectors are leaking fuel into the engine, and that the increased airflow is not having the same effect that it would if they were functioning normally.

-Charlie