carlrx791

Hey guys. I have a 1991 convertible, automatic transmission, nice well cared car and have two questions:
1. How can I set the idle speed on this car. I have the Chilton manual but it doesn't say much. When I got the car running and it reaches the normal working temperature, put AC on and reverse, the car just die because the idle speed is so low. I check the connectors that the book says but there are five connectors, one is white, two are green and two are blue. I am afraid to jump the wrong one. Or which os the right way to set the idle speed. I already put new spark plugs and K&N filter.
2. When the car has the AC on and its taking off, is very slow until the engine reaches 3k rpm, then pulls like a champ. but at the beginig is very "slow", it's that normal.
Please help I live in Florida and the weather is hot, I also have the black leather seats, so it's a need.
Thanks
Carlos

adamlewis

Warm up the engine and run it at idle

Turn off ALL electrical loads

Ground the test connector with a jumper wire

Take off the little cap from the BAC valve and adjust your idle speed my turning the air adjust screw







( From a 89 FSM )

carlrx791

Thnaks. I did that procedure but I was not sure what connector is the one, should be the green six slots with just two wires. If is that one, it did nothing to the car. I'll try again and I'll see what's happens
Thanks again
Carlos

Bambam7

What is your idle at while warm, notihing on? If it's 750, it's fine.

No... The test connector is the a SINGLE wire green connector, up at the front where the coils are. Ground it to the neg terminal on the battery, then turn the air adjust screw on top of the throttle body... it's under the black cap right smack in the middle of the top.
It's not the BAC to adjust on a 91. (Though it may need a good cleaning...)


I had that problem with the car dying when the air goes on, jacking the idle up over stock settings is just a bandaid solution. Check for vacuum leaks, and that your TPS and timing are properly adjusted.

black7

2. When the car has the AC on and its taking off, is very slow until the engine reaches 3k rpm, then pulls like a champ. but at the beginig is very "slow", it's that normal.


The ac puts more of a load on the engine so it will be slower with it on another thing is you have an automatic which really hurts acceleration drastically.

carlrx791

Please what is the BAC, where is it. was trying to do the right thing, I like workingin my cars but this is the most different way to adjust the idle speed from any car I had, Yes the car idles at around 500 rpm and I know the AC puts a load on the engine but as soon as put reverse, the car just die. If you guys can tell me where and how to start to find which could be the real problem I will appreciate it. by the way some times when the car is warm,I can hear like a major air suction noise. This is my second RX7 and the third in the family but this is the first that I'll like to keep and do maintenence, even if is slow, I actually sold my Corvette because I wanted a RX7 so bad.
Thanks

carlrx791

Well, I tried everything and still the car runs low, I know what and where is the BAC, It this BAC could be cleaned, it can be this the problem?

carlrx791

By the way, when the car is warm and with or with out he AC is around 500 rpm and just when I out reverse jusdt dies.
HELP

carlrx791

Another thing that I am corned about is when I accelerate the car a vibration is coming from the engine/transmission and I can feeel it even in the center console, shifter ashtray, even when the car is still and I rev the car to 4000 rpm the vibration can be felt.
Thanks guys
Carlos

Bambam7

I just saw the subject of this thread....
I wish I had a "Ho" to set my idle too!
"Change the oil too... bitch!"

rx7_ragtop

I usually use a screwdriver for setting idle... but if you want to try it with a hoe, you are welcome to.

Seriously, sounds like the idle setting question is answered. As for the vibration, I would suspect the u-joints in the driveshaft are worn out. (common problem)

Generally speaking, you have to replace the entire driveshaft, they aren't replaceable per Mazda. (It CAN be done by a competent shop that builds driveshafts though.)

Brad

dmyers

In regards to your idle problem: http://www.fc3s.org/
FSM has a walkthrough for adjusting the idle. I ran into the same problem last week. I suspect that I have a vacuum leak but adjusted the idle as a temporary fix.

carlrx791

I will go to driveshaft shop tomorrow and see if they can do the job, do you know how much a good profesional shop will charge for? About the Idle, the car went back to 500 rpm. I'll give it a try tomorrow again as well. I really like this car but even I had one in the past and my sister's that I drove it a lot, this one is like more sophisticated, complicated too. I think I like it enough to learn about 7's. I'll let you know guys.

Rotarius

The idle speed is set at the factory and the dealer has a device to put it where it should. Unfortunatly if you move the factory setting the hoe system is going to get "out wack" possibly causing other problems. My advise to you is not to mess with the idle speed IF nobody has mess with it in the pass. Most likely u just need a tune-up or have a vacuum leak. Fuel Injected cars are not to be treated as carbureted engines. Good luck....

carlrx791

You are totally and absoluty right, this is the first time in many years that I have a car with idle problems, usully the ECM takes care of that and many other functions, I actually enjoy working in my cars but this is kind of new for me. Iwant to do it right and I used towork in a BMW-VW-MAZDA dealer and I will try with them, but I remember they always coplainted about the prices and difficulties to fix "the R's". We'll se wat's happens. I'll let you guys know.
Thanks

Ziggy682

Hehe, yeah, just get your ho to set it and stop worrying.

carlrx791

Well I'm concern, I don't want to damage the car in any aspect, I love the car but parts are expensive and I don't want to hurt it

hugues

If you only have problems when AC on,
then it is coming from the BAC valve or the ECU connection to the BAC valve.

to chek if ECU is connected properly to BAC, at idle just unplug the BAC connector (at the BAC), the rpm should drop. If it does not do anything, the ECU/BAC connection is broken.

You can do some basic checks for the BAC valve itself. Get Haynes manual or get FSM from www.fc3s.org (the part about fuel and emissions)

Hugues -

carlrx791

Yes, is when the AC is on but still whenn runnig with out it still is low around 500 rpm back again and today with the AC the car started to act wierd and the Idle when up and down until I shutt the AC off the came back to normal,

carlrx791

Another thing I found out was that when I put drive or reverse, the rpm drops dramatically and special on reverse because the car just dies.

carlrx791

I was driving my car yesterday and it was around 95 degrees and I can tell you guys how much I like my car. The looks and how nice it drives but this problem with the idle is driving me nuts. When the car is stoped and the auto transmission is on neutral the idles is 750 rpm exactly but when I put drive goes down to 400 and if I put reverse just dies. Any other idea, because is auto should it have a different Idle?? Please help