BobfisH

Guys,
My RX keeps stalling at idle! Generally more so with the air con on, but it just dies slowly...it will idle at 1000 rpm, and slowly dropdown and stall eventually.

Spec is totally standard, except air filters and a 2k mile old motor.

Anyone have any ideas what to check? I'm pretty sure my earths arent great, but that shouldnt cause the car to totally stall should it? Also, why does this happen when air con is on?

cheers

Bad_Karma7

Air conditioner is adding a load to the engine. Are you on stock ECU or Aftermarket?

BobfisH

Spec is totally standard, except air filters and a 2k mile old motor.

Tim Benton

iTrader: (1)

What's it pull at idle in vacuum? Have a boost gauge? Does it idle at 750rpm?

Tim

BobfisH

Idle at vacuum is about just over -0.5 bar if i remember correctly; but im not sure on that one. I do have a boost gauge. Car idles between 900-1000 rpm ish i think. It also has a tendancy to bounce around and misfire and shake a bit at idle, but never under load or above 1200 rpm.

Narfle

iTrader: (16)

Sounds like a vaccum line issue. Jumpy/bad idle but running good under load is the giveaway.

HDP

iTrader: (2)

Also a bad apex seal...

PEGPEN

hopfully it not a bad seal, u just did a rebuild on it, that would be shitty.

Narfle

iTrader: (16)

Heh, when I broke a seal it wouldnt idle at all.

BobfisH

its idled bad since before the rebuild and after it continues to idle bad, despite me overhauling the entire vacuum hose system for the second time and using hylomar gasket on pretty much everything.

Ive been doing research, and read abuot the thermowax pellet going bad, causing the ISC to try and reduce the idle past its range and causing the jumpy idle. Also read about the clutch switch possibly causing this issue too.

Can anyone tell me how to test either? I've no idea where either of them are, or how to test them.

thanks.

1QWIK7

iTrader: (33)

Im having the same problem as you except my idle is fine, when im coming off first gear or shifting into a higher gear at low revs, the car will sometimes die on me.

Could a clutch switch really be a cause too??

Tim Benton

iTrader: (1)

Don (HDP) is right about a cracked apex seal. Idle's crappy but after 1500 car feels almost like a normal engine. What I don't understand is the high idle speed. Do you have a factory service manual? What about the colored vacuum hose diagram, got it?

Tim

BobfisH

The apex seal isnt cracked, unless i had a cracked apex seal, did a rebuild and installed a brand new mazda OEM cracked apex seal. The car idles ok most of the time, i just tends to die sometimes.

Yes i have the factory service manual. Yes ive got the coloured vacuum diagram, but its no use, because im using a completely custom turbo control solenoid setup; and no, this problem hasnt developed since installing them so has nothing to do with them.

Does anyone have any information on the thermowax pellet or the clutch switch?

HDP

iTrader: (2)

Mine idled rough for 2 years with one (or more) but ran like normal above 1500 RPM. Before I installed the PFC, my car would idle rough and slowly die after a few minutes especially when the A/C was on. With the PFC, I was able to bump up the idle to 1000 and the PFC would do everything within it's capabilities to keep the car running.

HDP

iTrader: (2)

Did you check the MAP sensor?

FLA94FD

I've spent about $700 trying to resolve this issue. A number of parts have been replaced, hell I'm sure that my tuner hates me. This is not an easy one. The next time I take my car I removing egr, double throttle, going non-sequential on 99' spec and adding an electronic boost controller. If that doesn't work I'm dropping a reliable LS7 under the hood and be done with it.

BobfisH

I think your all misunderstanding my problem. Its not that i cant get my car to idle. Its not that it doesnt drive ok. Its just that 1 in 5 times when i stop, the car wil slowly die on me. The idle also bounces around sometimes. Its not vacuum related as everything has literally been re-done about a week ago. Its something to do with the idling mechanism of the car im sure.

Does anyone have any info on the thermowax pellet or clutch switch? these are the things i want to check.

A la:

Date: Wed, 2 Feb 2000 09:44:38 -0600
From: "Westbrook, Chuck E." (CWestbrook@tmh.tmc.edu)
Subject: RE: (rx7) [3] Unstable idle

It usually is a combination affected by the idle level (idle set screw and air bleed screw), TPS setting, and cold start system(hot wax rod and fast idle cam). Once had the same problem and it was the hot wax rod gone bad. When it was adjusted for cold starting, it did not release enough when warmed up. This caused the ISC system to try to reduce the idle beyond it's control. This caused the oscillations in the system. Sometimes just having the idle bleed screw open too much can cause the problem because once again the ISC system is out of range. These symptoms can be also caused by small vacuum leaks causes the imbalance.

No easy solution! Just have to check all.


And:

Date: Sun, 2 Feb 2003 18:13:57 -0800
From: "DVanditmars" (DVanditmars@AutoSportRaceTech.com)
Subject: (rx7) [3] Idle

(my) idle problems have now been fixed on my car today!

Check that the clutch switch contact operates correctly
Either check the neutral switch from the transmission or just connect permanently to ground.
I fixed the clutch switch by replacing the spring, as mentioned by several listers. Permanently grounding the neutral switch was recently mention on the list as well. Thanks guys.



As the problem generally happens with the clutch down. Not sure if this is to do with the clutch switch however or just the extra inertia of the flywheel being engaged keeping the motor running.

HDP

iTrader: (2)

Ok, gotcha. Sorry we were of no help.

BobfisH

no worries bud, any idea where the hot wax rod thingy is? or the clutch switch or how to test it?

BobfisH

nobody?

HDP

iTrader: (2)

If you are still running the stock ECU, I would first check your engine codes to see if there are other issues. For info on the waxrod and FIC, check page F-79 in the FSM.

BobfisH

Thanks HDP!