4age common low idle problem fix?

gmacrae · Post by **gmacrae** » Fri Jun 03, 2005 12:28 am

Hi ppl, my fxgt has a very low idle when its hot, common problem with 4age's i know. Has anyone ever actually worked out a fix? idle speed isnt actually adjustable is it?

just sick of pulling up to light and having the car stall on me, any info would be great - Cheers

Gene

THA SHZ · Post by **THA SHZ** » Fri Jun 03, 2005 8:30 am

check ur thermostat and fan is workin , this was the probs in mine

gmacrae · Post by **gmacrae** » Fri Jun 03, 2005 8:42 am

ah yep, had the thermostat out on the weekend, ran the water temp sensor dry till the thermostat opened back up, i bet the ecu is still freaking out about that, ill clear it and see what happens - Cheers:)

ChaosAD · Post by **ChaosAD** » Fri Jun 03, 2005 6:26 pm

yes there is an idle adjustment screw. its down a hole on the top of the throttle body. may or may not have a cap covering it

dxtawagon · Post by **dxtawagon** » Fri Jun 03, 2005 6:32 pm

yes i have this problem too. its freakin anoying still dont know what it is or how to fix it??
hope someone posts a solution to this problem

Post by **Mr Revhead** » Fri Jun 03, 2005 6:49 pm

sticking idle valve?

iv heard of them idling high, but not low.....

matt dunn · Post by **matt dunn** » Fri Jun 03, 2005 7:24 pm

ChaosAD wrote:yes there is an idle adjustment screw. its down a hole on the top of the throttle body. may or may not have a cap covering it

To correctly adjust idle speed you must

first set the TPS correctly.
then set the
Ign timing correctly,
then you can adjust the
idle speed.

If they are not correct and not done in that order it will not be correct.

Matt

kingcorolla · Post by **kingcorolla** » Sat Jun 04, 2005 3:06 pm

yep that bastard cold idle valve is a common one.
When the car is up to temp, (and idling low) try blocking the air entry port on the filter side of the throttle plate. If your idle stays the same then that idicates there is little air exiting the valve. If the engine dies when you block it then the could be elswhere. Clean it out and give it a blow with a duster gun if you can be f%$#d

doing TPS and setting base idle to start with is definately a good idea

ae92levin · Post by **ae92levin** » Sat Jun 04, 2005 4:42 pm

yeah my 4age used to do that, just turned up the idle.

yobbosayo · Post by **yobbosayo** » Tue Jun 07, 2005 9:45 pm

from what I've read on here this is a common fault and it is caused by the auxiliary air valve.
Mine does exactly the same thing, stalls at idle when hot, so I finally bought the part that I hope will fix it. I was going to put it in on the weekend but i realised that I needed the gaskets so I ordered those today. I'll report back if it fixes the problem.

Just check the haynes manual, there's a section on testing and replacing the auxiliary air valve. It sits just underneath the throttle body. Of course I didn't bother with testing it, cos I prefer to throw my money away in the hope of a fix :roll:

so it will be interesting.

I bought the part off revhead, $185 delivered, so the price is what puts most people off fixing them. Oh, and you will need the gasket and o-ring for the valve, and the gasket for the throttle body too, which altogether cost about $15.

suberimakuri · Post by **suberimakuri** » Wed Jun 08, 2005 12:12 pm

i always pull off the water stuff under the throttle and block it up.
warm idle about 200rpm higher then cold idle.

CAMB01 · Post by **CAMB01** » Wed Jun 08, 2005 7:48 pm

4AGEs need stepper motors, like mitsi's do.

suberimakuri · Post by **suberimakuri** » Wed Jun 08, 2005 7:52 pm

nope.

ndeany · Post by **ndeany** » Thu Jun 09, 2005 11:31 am

my ae101 4agze is doing the same thing at the moment... Replaced the air filter, needed a new one anyways, but no difference... Well the only difference is that she aint stalling anymore, but still idles at about 500rpm when hot.. If you play with the idle won't it therefore idle too high when the choke is engauged, but then obviously be sweet when not engauged??? Surely there's an actual way to fix the problem, rather than trying to compensate by uping the idle... I'm getting mine looked at today by a local mechanic that used to work for toyota... Let you know how it goes...

NZ_AE86 · Post by **NZ_AE86** » Thu Jun 09, 2005 1:16 pm

matt dunn wrote:
ChaosAD wrote:yes there is an idle adjustment screw. its down a hole on the top of the throttle body. may or may not have a cap covering it

To correctly adjust idle speed you must

first set the TPS correctly.
then set the
Ign timing correctly,
then you can adjust the
idle speed.

If they are not correct and not done in that order it will not be correct.

Matt

As Matt said. It is a very simple system, the only other thing is to make sure that the car is coming up to correct temp and STAYING there. Then do as Matt says.

ndeany · Post by **ndeany** » Fri Jun 10, 2005 2:26 pm

ive just had my low idling problem fixed. all that the bill says is: "brought car up to temperature. Checked idle. Slightly low. Checked and cleaned all electronic connections and vacuum lines. Adjusted idle screw so that will idle at approximately 750rpm. Road tested and rechecked. All ok."

ChaosAD · Post by **ChaosAD** » Fri Jun 10, 2005 6:14 pm

What the cold idle valve does is let extra air into the manifold when the car is cold.
Water from the cooling system is fed into it and when the coolant heats up it melts a wax pellet in the valve causing it so close the cold idle valve and drop the idle.

The pellet is easily damaged by overheating and possibly age. When it is damaged it will let air into the manifold wether the engine is cold or warm.

This causes a the car to continually idle high even after it has warmed up. This usually cannot be cured by adjusting the idle screw as the cold idle valve simply lets too much air in.

If the car ildes too low then just give it a tune up and adjust it as detailed above.

yobbosayo · Post by **yobbosayo** » Fri Jun 10, 2005 9:46 pm

yep, well I fixed it. It cost me $200 and then I find out I could have just adjusted the idle screw which is sitting on top of the throttle body.

well maybe. Mines a bluetop and I replaced the part then adjusted the idle like the haynes manual said, and now it's pretty much perfect. cold idle at about 1500, and hot about 800. So who knows. It wouldn't surprise me if I spent $200 for nothing. One day I'll learn how to stop wasting money on cars

rwd_mayhem · Post by **rwd_mayhem** » Thu Nov 16, 2006 6:35 pm

Karl_Skewes wrote:i always pull off the water stuff under the throttle and block it up.
warm idle about 200rpm higher then cold idle.

so that doesnt effect it too much? wont die when cold? iv thought about doing this as mine are not connected at all and it revs from 2200-3000 eractically.

l1ttle_d3vil · Post by **l1ttle_d3vil** » Thu Nov 16, 2006 8:22 pm

the erratic idle will probably be as a result of too much air going into the engine, so your idle is probably set too high, or the aux bypass valve is stuck open or something along those lines.

i've removed all the waterlines and bypass valve on my 4age too, alot tidier without all those waterlines. it starts fine, even on cold mornings and idles at about 800rpm when dead cold, and about 1200rpm when warm. I can lift the idle a bit, but then its too high once it warms up.
it isnt too bad when cold, but if I hit the gas then let the revs drop to an idle it'll shudder slightly as if its almost going to stall, but never does. thats only for about the first 30 - 60 seconds anyway.