RX7SERIESV

Hi, I've got a problem (the car), the prob is when im at a standstill with the car running and in park (car at normal operating temp), I turn my wheel either way at the same amount and my car's revs will drop really low, almost stalling then quickly go back up to normal.
And also whenever I am reverse parking or doing a U-turn with the steeringwheel at fullock the car will stall. Why??
What could be causing this?? I was thinking maybe it is the power steering mechanism engaging and causing it to drop the revs.

PLEASE HELP AN OZZIE OUT!!!
thanks for ur help guys.

SonicRaT

iTrader: (6)

You need to disconnect your BAC and adjust your idle. Your idle is probalby set to low, and the BAC is using all of it's ability just to get it to idle normally, which is why it drops so much when you turn the wheel, because it can't compensate enough on it's own.

Node

iTrader: (1)

mine does it but its due to the PS i think.

my idles definately fubared got nice intake leaks and exhaust leak.

SonicRaT

iTrader: (6)

It's not the PS, it's the damn BAC's inability to move more air at 100% DC just to keep the car idling with no load.

NZConvertible

No, it's not the BAC's inability to pass enough air. It worked perfectly when it was new, so it's obviously big enough. It's possible that the BAC valve is internally dirty, which would reduce it's effectiveness. It should be removed and cleaned out. It's also possible the BAC valve isn't even working, so that should be checked too.

I'm assuming this is an NA, not a Turbo. Turbos use a seperate air supply valve to do this job.

SonicRaT

iTrader: (6)

When perfectly new it wasn't running at some variable duty cycle just to keep the car idling. What I'm saying is, that if he unplugged his bac at idle with no loads, i'd wager the car would die because the BAC is doing all of the work keeping the car running.

So... at 100% DC it idles at 750.... what happens when you put load on it and it can't open any wider? Not enough flow to keep up, because the mechanical idle is set too low and making the BAC work too hard to just keep a normal idle.

NZConvertible

Yes it was. That's exactly what an idle control valve is supposed to do; control idle speed by varying the amount of air bypassed.

It should never be at 100%. Testing has shown it operates well below that.

SonicRaT

iTrader: (6)

It think you're missing what I'm saying. What I'm saying is, is that the idle without the BAC is so low the car won't even run (or will run at like 200-300rpm). The BAC is then running a high duty cycle just to keep the car running with no load. Once you put load on it, the BAC has to run even more DC just to keep up, and sometimes can't. This is why i suggested setting the idle rather normal without the BAC, then plugging it back in. It's fixed this sort of thing on every car that I've found that had this problem.

RETed

Um, do you have the air bypass valve specifically for the power steering?
All U.S.-spec FC's should have the, unless someone yanked them out.
I know some of the J-Specs don't.

Look at the rear driver's side (assuming it's RHD) rear corner of the intercooler - is there at least one or two fittings coming off of it?
If so, one of them is for power steering idle compensation.
If the car has been serviced and someone removed the upper intake manifold, a lot of times the solenoid does not get plugged in or the wires get damaged due to them getting pinched.


-Ted

SonicRaT

iTrader: (6)

Looks like a non-turbo to me Ted.

NZConvertible

If unplugging the BAC valve causes idle to drop that low, something else is wrong, like a vac leak. You are not describing normal operation here. Nothing in the original post described any other idle problems.

What you're supposed to do is jumper the initial set coupler so that the ECU stops trying to compensate with the BAC valve, and then set the idle speed. Unplugging the BAC valve is not necessary.

Back to the original problem, the NA ECU cranks up the idle speed based in inputs from the power steering pressure switch on the pump. If this switch has failed (uncommon but possible), then the described symptoms will occur.

SonicRaT

iTrader: (6)

Yes, it's not normal. Neither is stalling. I say unplugging it loosely, I generally just yank the plug to diagnose, then fix it with the initial set, and plug it back in, simply because it's easier for me to just pull the plug and see what it does than find a way to jumper the initial set. But your advice is better for that route.

But, I was figuring that with his reverse issue (since the pump isn't dragging all too much when at lock), was an indicator of the BAC being overworked by a poor mechanical idle (again, as you said, caused by vac leaks/etc).

beefhole

iTrader: (29)

How do I jumper the initial set coupler? I have various idle gremlins with loads on the motor, and I fear my BAC is not working correctly.

RETed

They have non-turbos in Australia??? O_o


-Ted

SonicRaT

iTrader: (6)

Not sure, but it's definatly an N/A (he said in a previous thread).

vicious525E

dont know if im the only person that caught this, but he says that the idle drops with the load, and im assuming, quickly jump back up (still with the load). if the bac was working at full load, or anything close, it wouldnt be able to bring the idle back up, the extra load from the ps would just lower the idle until the load was removed. i say, check the bac valve, i think haynes has a way to check the bac, and clean if needed, if it looks to be in good shape. then im wrong and you may just need to adjust your throttle stop, and then adjust your bac valve accordingly, and, because i know no one botheres the mention this, if you adjust your throttle stop, you'll have to readjust your tps. so keep that in mind too.

my .02

SonicRaT

iTrader: (6)

Even with the bac low and turning on load the engine will try to compensate and drop down and find it's way back up. But also you can't turn the wheel forever, so it makes sense that it bounces back up when you stop/etc.

RETed

Aw crap, you think I got time to look at every single thread?


-Ted

SonicRaT

iTrader: (6)

Nope! Haha, I saw Australia, so I was like, ok TII. Then I saw the sig with an N/A hood, and I was like, ooh, a sleeper, then I saw the non-turbo 15's, and I was like... that's odd. Then it was an automatic (yeah I know they had automatic TII's), so I was like this seems odd, quick search of his 5 posts resulted in a thread that he mentioned it was an n/a.

xtremeskier97

Way to be thorough SonicRat.

Blowtus

sonicrat's suggestion is a good one... whether you unplug the bac or find the initial set coupler (buggered if I could find mine) setting the idle to 750 at the throttle body makes a big difference.

DriftingB26RX7

iTrader: (4)

dont know if anyone put this but, the only reason y your revs go down if you have power steering ofcorse...when you turn the wheel you tell the p/s that u need help and it helps you turn so easy...if you have ever drove your 7 with no p/s and you turn the wheel, that does not happen...this only happens when your sitting right...remember you have alot of weight on the front end kinda so u gotta turn thoes wheels...and dat motha ****** p/s is gonna help you ok....good, have a nice day BADDDA BING

J-Rat

iTrader: (2)

Yeah..

Too bad those pesky Mazda engineers designed the system to increase engine idle to compensate for the additional load.

Damn engineers..

NZConvertible

Australia got a similar line-up to the US; a turbo coupe, a non-turbo coupe and a non-turbo convertible.

vicious525E

that made my brain throw up...