demontwig

So my problem is after it's warmed up and I come to a stop, or anytime I disengage the clutch while driving, when the revs drop to idle the car dies. I have an 11# flywheel and I am thinking the dashpot needs adjusting to compensate. But yet some people run with them removed, so could that be it? The weather sucks right now and I don't want to go tearing things apart, that's why I haven't tried to adjust it. I have searched and that's how I came to this conclusion. I was wondering though, is there anything else that would cause it to die like that? It's a fresh rebuild (~200 miles) with large streetport and no fuel controller yet, could it just be dropping too much fuel into the engine and flooding it out when disengaged? Just trying to pick some brains here since I really want to drive my 7 but can't since it stalls all the time. Thanks!

texFCturboII

iTrader: (17)

Mine was doing that for a while. I replaced the TPS and it was fine, but now my alternator is crapping out and it's doing it again. So check your TPS and your alternator, good luck!

Roen

iTrader: (2)

TPS adjust, then idle screw adjust.......cured it for me. If you have to, raise the idle for your initial break-in, then lower it again once the engine is nice and happy.

Make sure you properly break-in that engine.

demontwig

I don't know how to adjust the tps but I can look it up. I'm pretty sure pineapple got it right since they installed my engine, but they've been crazy busy lately and I haven't really been able to talk to Rob to get his opinion. And...this may sound stupid, but how do you adjust the idle speed? Someone said I could by adjusting the BAC valve, and it didn't do anything. I also tried to richen up the variable resistor, and it helped some, but I can't get the car to idle higher. Vacuum leaks? They chased down most of them when they were completing it...

Roen

iTrader: (2)

oh.....if they adjusted it, then don't bother. Just look up instructions on how to adjust idle and raise your idle slightly.

I have an S5, so I use my idle adjust screw on top of the TB.

demontwig

So is that what you're thinking it is, instead of the dashpot? The idle just being too low? It is quite a large streetport on the stock ecu

Roen

iTrader: (2)

Hey, at least it'll get your car running!

This way, you can break-in the motor at the expense of using a little more idle gas.

You can always lower the idle later.

What's your idle at, anyway?

demontwig

I was going to raise it but I couldn't. Maybe I missed something. I don't mind the gas that much, I DD a 375 hp small block that gets 9mpg on premium.

My idle is around 750 sometimes, but usually around 700, sometimes less like 600, and it just wants to stall when I come to a stop or disengage the clutch while cruising.

Roen

iTrader: (2)

stock is 750 rpm +/- 25 rpm. You can get away with 800-900 for the time being.

roland88

I had this same problem and didn't seem to matter what I did with TPS, idle or bleed adjustments - other than making it idle too high.

I took it to Mazda and ... Believe It Or Not, they changed the throttle cable - now it is steady as a rock.

Go figure

demontwig

The random idle or the stalling thing? Because actually my throttle cable is shot to ****

Roen

iTrader: (2)

whoa......the dealerships know how to work rotaries down under!!!!!

demontwig

lol I actually have a decent one in my town, much to my surprise/delight. Maybe I'll get that taken car of since it needs to be done anyway. Might solve my problem I suppose.

roland88

There are still some die hard RX7 race heads at a couple of the dealerships - just gotta know where to go. As much as I often bag the Mazda dealerships, they do have the Mazda factory resources (secrets, if there are any left). You just have to make sure they don't touch anything else.

How about this one, last time I went for a general service, the Service Manager said they had a "software update" for the ECU - and we all know what type of bullshit that was.

demontwig

Sig material right there

Roen

iTrader: (2)

haha.....well, it made sense for the RX-8 though.....

demontwig

So how important is it that I jumper the initial set coupler when setting my idle speed via the BAC?

Roen

iTrader: (2)

not very.....but do it anyway. If you don't have jumper wire or a multi-meter, then don't bother.

I didn't do it the last time I set my idle to 750.

demontwig

Jumper I can make, the multimeter no...well, maybe. But I thought I was supposed to need that to set the dashpot, not the idle. I think the jumper might be helpful since it doesn't seem to make a difference when I adjust the BAC valve. How many turns in either direction should it be until I noticed something?

Roen

iTrader: (2)

the multimeter is just used to substitute for the jumper wire, that is, so that you can ground the ISC to the battery.

You have an S4, an REW-swapped S4, which I don't have any experience at all. I can only tell you how the S5's idle screw works, which is that left turn increases and right turn decreases. On the S5's, you can notice the idle change immediately.

demontwig

hm. You didn't jumper the coupler? Because I can turn mine unjumpered 5 times to the left and not notice anything. Maybe it's faulty? You have a turbo right?

roland88

run through some of the suggestions here: http://www.fd3s.net/idle_adjustment.html


- still think it's your throttle cable

Roen

iTrader: (2)

nope.....NA

HAILERS

They have you jumper the initial set coupler to put the BAC's duty cycle at a set value that will not change as you make adjustment. If you don't, then the ECU/BAC working togther will work against the adjustments you make.

The BAC screw won't have much of any effect if the idle is above approx 750-800rpm, nor the screw on the dynamic chamber on a non turbo. If it's idling higher than that, there's something amiss elsewhere.