Idles problems please help me!
05-07-06, 08:53 PM
#1
87 Mazda Rx-7 Mods**91 JDM
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Idles problems please help me!
OK, I have looked for vaccum leaks I have taken to Rx7 mecanics even to the dealer And nothing i have try lots of things finally am concluding it's not the vaccum leaks (I think) Is there anything that would make your car go down rpms when you go to a stop sign or it would be idleling normal then it would go down has anybody had this problem that can help me or lead me to the right way please this is annoying
05-07-06, 09:01 PM
#2
BAC valve maybe. I'm having a similar problem when mine is cold the idle is low, or when I rev and it drops back down it almost dies and comes back up. I cleaned the BAC valve today and it helped some but the problem is still slighty there. Not as bad though.
05-07-06, 09:20 PM
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off the plenum (thing that says 13b injected) there is that cylinder looking thing that is attached. with the black end . with the allen bolt in the center. and a wire clip on it. it has 2 colant lines runing threw it. and has a rubber hose connected to it from your intake. . you can take that off and clean it i guess. as the guy befor me said.
i have the same problem as you . i thought it was my tps. i still think my tps has something to do with it. but the bypass air controle valve can also cause problems. it is the thing that kicks on when you turn on ac. or turn your power stearing.
if i pump my breaks my car stalls
i come to a stop. or press in my clutch my car stalled
i had to toe heal . but the problem got worce so i stoped driving it
i got a new alternator ruling out that problem
then i just adjusted my throtle cable ( there are 2 screws on either side of a holder that the throtle cable i just tightend that up so it idles between 1500-700. so when i come to a stop it hits 700. not stall
this is a bandaid for the problem. it will not FIX it. my car sometimes idles at 3000 . thats bad. you'll here a slow beeping warning noise if this happens.
it is a warning saying your engine speed is more then 2200 rpm and your transmition is not spinning. the warning means little but that.
have a good day!!!!
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05-08-06, 12:59 PM
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take the intake manifold off yourself. thats what i had to do. i found leaking gaskets, bad EGR valve (common problem for 86-88 non turbo) and crud covering my fuel injectors. I havent finished, but i'm sure its one of those things were hurting my idle.
05-09-06, 10:53 AM
#11
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Yes, there could easily be something else. Bouncing idle is typically caused by the TPS. First, make sure it is completely functional and adjusted within specs. Set it with one method and verify it with another. I set mine by twin lights, and verify with resistance set at near 1K OHM.
The BCS is responsible for evening out the idle when some kind of load is placed on the engine such as the A/C. It wouldn't hurt to remove the BAC and give it a thorough cleaning and testing. 12 volts applied to the electrical terminals should result in the actuation of the BAC. You will hear a distinctive click.
After that, check all possible places for vacuum leaks. The vacuum leak I had that screwed up my idle was a torn gasket at the LIM. Then check the fuel filter. Replace it if it is old. A clogged filter can surely screw up the idle.
You have to investigate and eliminate things one at a time. There's no magic button you can push and make it all better.
The BCS is responsible for evening out the idle when some kind of load is placed on the engine such as the A/C. It wouldn't hurt to remove the BAC and give it a thorough cleaning and testing. 12 volts applied to the electrical terminals should result in the actuation of the BAC. You will hear a distinctive click.
After that, check all possible places for vacuum leaks. The vacuum leak I had that screwed up my idle was a torn gasket at the LIM. Then check the fuel filter. Replace it if it is old. A clogged filter can surely screw up the idle.
You have to investigate and eliminate things one at a time. There's no magic button you can push and make it all better.
05-09-06, 09:31 PM
#12
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ok i have taken out my BACV and sort of clean it and i have made progress my car now doesn't idle like it use to before but it's still kind of funny how do you adjust your TPS?? i have a S5
05-14-06, 11:30 AM
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ok so my car now does not what to idle where it should like 850 i guess but it only idles at 2k thats to high but it i try to bring it down where it supposed to (press the back of the paddle with my feet ) it wants to die so can this be cuz of the acceleration cable adjusted wrong??? or can it be my tps???
05-14-06, 05:09 PM
#16
I'm havin the exact same problem. If you unplug the BAC while the car is running and the engine idle doesn't change then the BAC is bad. Mine is bad so i'm replacing it soon. I checked my tps and it looked pretty close to specs, but when i put everything back together my throttle was sticking horribly. Took the intercooler off and pulled off the hose on the top of the throttle body (TII) and all this brown coolant gunk came out of it. I'm guessing my throttle body is clogged. So you might want to check it on yours.
05-16-06, 12:57 PM
#18
I'd also check if the BACV is getting the right voltage at the ECU. Check terminal 2Q and ensure it's 8-12v after the car is warm.
And do this:
And do this:
Originally Posted by teamfc3s.org
3. Turn off the ignition. Remove the connector from the BAC valve and check the resistance of the BAC valve solenoid. This is done by connecting an ohm-meter across the BAC valve terminals. Care must be taken not to let the probes touch each other or you will get a false reading. You should get somewhere between 10 and 20 ohms. The manual says 10.7 to 12.3 ohms, but it's really not that picky. What you don't want is near zero ohms (solenoid is shorted) or very high resistance (solenoid is open-circuit.) If you have a shorted or open-circuit solenoid, you will need to replace the BAC valve. You might want to try disassembling it just on the off chance that it is repairable.
4. With the connector still removed, and the engine still off, place a 10k ohm, 1/4 watt resistor across the terminals of the connector. This is easy to do, simply insert the resistor leads into the connector. Make sure that the leads of the resistor do not short against each other or anything else. Turn the ignition on, without starting the car, and measure the AC voltage across the resistor. You should get a value between 6 and 7 volts after it settles down. A voltage lower than 5V indicates a likely ECU failure. Go here for more information. If you get the correct voltage, move on to the next step.
NOTE: This is a good chance to check that the conductors in the connector are firmly seated. Mine came loose, slid down, and shorted out, causing ECU failure. More on that in a moment. At the very least, if they are sliding around, they aren't making good contact. If you find that the conductors are loose in the connector, press the wires from the back of the connector towards the front. They should snap into place and not slide back. If they do slide back, you will need to either get a new connector, or epoxy them in, like I did. It works. (Be careful not to get epoxy on the connector surfaces!)
NOTE: Do not perform the following test if you obtained a reading of 0 ohms (short circuit) when you measured the resistance of the solenoid above. Something will get *very* hot.
5. The BAC valve may be stuck. Using jumper wires, connect 12V across the solenoid leads, being extremely careful not to create a short. If you didn't get an open-circuit reading when you measured the resistance of the BAC valve, the valve should click. If it is stuck, doing this a couple of times should free up the valve. I would also recommend removing the BAC valve from the intake manifold (this can be accomplished without removing the water hoses connected to the valve) and spraying WD-40 into it. Work it a few more times with 12V. If you can't get the thing to click this way, replace the BAC valve.
4. With the connector still removed, and the engine still off, place a 10k ohm, 1/4 watt resistor across the terminals of the connector. This is easy to do, simply insert the resistor leads into the connector. Make sure that the leads of the resistor do not short against each other or anything else. Turn the ignition on, without starting the car, and measure the AC voltage across the resistor. You should get a value between 6 and 7 volts after it settles down. A voltage lower than 5V indicates a likely ECU failure. Go here for more information. If you get the correct voltage, move on to the next step.
NOTE: This is a good chance to check that the conductors in the connector are firmly seated. Mine came loose, slid down, and shorted out, causing ECU failure. More on that in a moment. At the very least, if they are sliding around, they aren't making good contact. If you find that the conductors are loose in the connector, press the wires from the back of the connector towards the front. They should snap into place and not slide back. If they do slide back, you will need to either get a new connector, or epoxy them in, like I did. It works. (Be careful not to get epoxy on the connector surfaces!)
NOTE: Do not perform the following test if you obtained a reading of 0 ohms (short circuit) when you measured the resistance of the solenoid above. Something will get *very* hot.
5. The BAC valve may be stuck. Using jumper wires, connect 12V across the solenoid leads, being extremely careful not to create a short. If you didn't get an open-circuit reading when you measured the resistance of the BAC valve, the valve should click. If it is stuck, doing this a couple of times should free up the valve. I would also recommend removing the BAC valve from the intake manifold (this can be accomplished without removing the water hoses connected to the valve) and spraying WD-40 into it. Work it a few more times with 12V. If you can't get the thing to click this way, replace the BAC valve.
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