Yes, another Idle issue

mazdasport · 04-07-2011, 08:50 PM

[96 ba astina 180se, exhaust, Cai with panel filter]
Hi guys, so all the other idle probs fixed up now.
just one thing that bothers me.

Problem is that even when I close the IAC screw at the top of the TB,
the idle doesnt ever go lower than 750ish. even if I unplug the IAC with the
screw fully closed and bridging the GND & TEN, Does anybody have any idea what could be causing such a fault? car is running well, just the idle sitting too high for the past few days.

Could it be when I cleaned and replaced the IAC valve. i removed the entire TB, but used the same gaskets, they were metal gaskets anyway. and there was two rectangular rubber gaskets.
could that be the fault,
all help apreciated.
thanks guys

DavoAust · 04-07-2011, 11:16 PM

As fair as I knew and have seen, 750 is the normal idle for a 1.8. It'd struggle to idle much lower..

project.r.racing · 05-07-2011, 06:47 AM

800rpm +/- 50rpm is normal.

No IAC screw on top of throttle body.

stock is best · 05-07-2011, 07:49 PM

if it helps at all, i have a stock 98 BA 1.8 auto and it idles at around 750

maztech · 05-07-2011, 08:06 PM

Sounds like it has an air leak check throttle body gaskets should be able to adjust idle lower than that . If all checks ok look at iac valve not closing fully.

mazdasport · 14-07-2011, 04:42 PM

@maztech...sorry about the late reply. have not been able to get around to it,
but anyway i am going to remove the Tb and Iac valve for leaks around the gaskets, as i feel you are right on that point. and i have found that the Iac valve is still sticky as it works somedays and somedays doesnt. so im going to try soaking it in WD40. is there anything i should consider when doing that except for not soaking the electrical connectors?

mazdasport · 14-07-2011, 04:44 PM

and is there by any chance that the leaking gaskets around the Tb and IAC valve could be causing the increased petrol consumption and smoke out of the exhaust , which is definitely burning rich, and i see its getting worse by the day whenever you give the car a revv

mattylagana · 14-07-2011, 04:46 PM

dude your car shouldn't be idling that low anyway, you should want it around 850-900 should be were you want it.

mikey_something · 14-07-2011, 05:02 PM

Quote:

Originally Posted by mattylagana

dude your car shouldn't be idling that low anyway, you should want it around 850-900 should be were you want it.

Quote:

Originally Posted by project.r.racing

800rpm +/- 50rpm is normal.

come on man...

mattylagana · 14-07-2011, 05:48 PM

lol especially cause it's an auto haha, do you Ever brake hard and have your engine stall?

04-07-2011, 08:50 PM	#1
mazdasport Junior Member Join Date: Oct 2010 Location: Durban, South Africa Car: 1996 Mazda Astina 180i se BA Posts: 67	Yes, another Idle issue [96 ba astina 180se, exhaust, Cai with panel filter] Hi guys, so all the other idle probs fixed up now. just one thing that bothers me. Problem is that even when I close the IAC screw at the top of the TB, the idle doesnt ever go lower than 750ish. even if I unplug the IAC with the screw fully closed and bridging the GND & TEN, Does anybody have any idea what could be causing such a fault? car is running well, just the idle sitting too high for the past few days. Could it be when I cleaned and replaced the IAC valve. i removed the entire TB, but used the same gaskets, they were metal gaskets anyway. and there was two rectangular rubber gaskets. could that be the fault, all help apreciated. thanks guys __________________ Mazdasport

04-07-2011, 11:16 PM	#2
DavoAust Senior Member Join Date: Mar 2007 Location: Brisbane Car: Red '93 3000GT / Black '08 Ninja 250R Posts: 2,930 View Photos By: DavoAust	As fair as I knew and have seen, 750 is the normal idle for a 1.8. It'd struggle to idle much lower.. __________________ Understeer is when you hit the wall with the front of the car and oversteer is when you hit the wall with the rear of the car. Horsepower is how fast you hit the wall, torque is how far you take the wall with you. '97 1.8L Hardtop '93 3.0L TT 3000GT

14-07-2011, 04:42 PM	#6
mazdasport Junior Member Join Date: Oct 2010 Location: Durban, South Africa Car: 1996 Mazda Astina 180i se BA Posts: 67	@maztech...sorry about the late reply. have not been able to get around to it, but anyway i am going to remove the Tb and Iac valve for leaks around the gaskets, as i feel you are right on that point. and i have found that the Iac valve is still sticky as it works somedays and somedays doesnt. so im going to try soaking it in WD40. is there anything i should consider when doing that except for not soaking the electrical connectors? __________________ Mazdasport

14-07-2011, 04:44 PM	#7
mazdasport Junior Member Join Date: Oct 2010 Location: Durban, South Africa Car: 1996 Mazda Astina 180i se BA Posts: 67	and is there by any chance that the leaking gaskets around the Tb and IAC valve could be causing the increased petrol consumption and smoke out of the exhaust , which is definitely burning rich, and i see its getting worse by the day whenever you give the car a revv __________________ Mazdasport

14-07-2011, 04:46 PM	#8
mattylagana Senior Member Join Date: Jul 2011 Location: Nsw, wollongong :) Car: Ba 323 Astina hatch V6 Posts: 615	dude your car shouldn't be idling that low anyway, you should want it around 850-900 should be were you want it. __________________ >97' V6 MAZDA 323 S3\|Sunroof\|18"x8" RX8 rims\|Custom Cold air intake\|klze headers, 100cpi cat, resi delete, Apexi back box\|Top Gun Leads/NGK Platinum Iridium plugs\|Soundstream Sound\|Lowered on yellow speeds\|Whiteline heavy duty swaybar\|cusco front strutty\|momo steering\|short shifter\|Lantis door sills\| This is my girl sxc isn't she? http://www.astinagt.com/forums/showthread.php?t=18139

05-07-2011, 06:47 AM	#3
project.r.racing Senior Member Join Date: Sep 2004 Location: n/a Car: n/a Posts: 10,929	800rpm +/- 50rpm is normal. No IAC screw on top of throttle body.

05-07-2011, 07:49 PM	#4
stock is best Junior Member Join Date: Apr 2007 Location: Sydney, Miranda Car: 97' Astina BA Hatch Posts: 219	if it helps at all, i have a stock 98 BA 1.8 auto and it idles at around 750

05-07-2011, 08:06 PM	#5
maztech Senior Member Join Date: Aug 2009 Location: QLD Car: ...... Posts: 952	Sounds like it has an air leak check throttle body gaskets should be able to adjust idle lower than that . If all checks ok look at iac valve not closing fully.

14-07-2011, 05:48 PM	#10
mattylagana Senior Member Join Date: Jul 2011 Location: Nsw, wollongong :) Car: Ba 323 Astina hatch V6 Posts: 615	lol especially cause it's an auto haha, do you Ever brake hard and have your engine stall? __________________ >97' V6 MAZDA 323 S3\|Sunroof\|18"x8" RX8 rims\|Custom Cold air intake\|klze headers, 100cpi cat, resi delete, Apexi back box\|Top Gun Leads/NGK Platinum Iridium plugs\|Soundstream Sound\|Lowered on yellow speeds\|Whiteline heavy duty swaybar\|cusco front strutty\|momo steering\|short shifter\|Lantis door sills\| This is my girl sxc isn't she? http://www.astinagt.com/forums/showthread.php?t=18139

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