4AGZE Idle

[sopachrga]

hi

on my '87 SC MR2 my idle is all screwed up.

As far as I can tell there are no air leaks and no air in the coolant system.

idling at about 900-1100 rpm if I give the car a rev the car will rev up then when it goes back down it will bog down too low and stall. but if I increase the idle to a stage where it doesn't do that it will idle warm at about 1300 and cold at about 1500-1600.

I think the throttle stop grub screw is out of adjustment, how do I set that properly?

Once that is right I will set the TPS, it seems right at the moment but if the grub screw is wrong I can't really tell.

Does any one else have an idea what could cause this??

[vvega]

ajust the tps first

have you flushed out the water temp sensor in the throttle body
it coulds well be blocked

im guessing its a map system ???

[sopachrga]

No it's AFM, yeah I pulled the throttle body the other day and gave it a complete clean, but no help.

[matt dunn]

ajust the tps first

have you flushed out the water temp sensor in the throttle body
it coulds well be blocked

im guessing its a map system ???

You are not meant to shag with the throttle stop.

With the engine not running use some carb cleaner on a cloth and clean it out.

Then adjust the throttle stop. Wind it right back so it doesn't touch and the throttle plate is fully closed. Wind it in till it touches then 1 more full turn. Lock it up.

Then adjust the TPS so the idle contacts are correct.

Then start the engine and warm it up.

Bridge out the check connector then check/adjust the ign timing.

Then you can adjust the idle speed with the throttle bypass not the throttle stop!

You must have all these thing correct before you attempt to set the idle speed or else you will be pissing into the wind basically.

We get so many people in at work that think they can just play with it while it's running not realising that if they wind the idle down the ecu just ups the timing etc to compensate then end up with the settings so far off when you snap the throttle then let it go the ECU has not enough control left to stop it from stalling.

Matt

[sopachrga]

Hmmm, me thinks my TPS might be knackered, Between the two centre terminals on the TPS, I have infinate resistance, no matter where the throttle is!

[matt dunn]

Hmmm, me thinks my TPS might be knackered, Between the two centre terminals on the TPS, I have infinate resistance, no matter where the throttle is!

If the tps is out of adjustment there will always be no conection.
And they're the wrong trrminals to test anyway.

The terminals are, in order from the one with the brown wire first,
1 earth
2 idle contact
3 tps signal
4 5 volt feed.

So you were checking between the two signal wires where you should be checking between terminals 1 earth and 2 idle contact.

With the throttle closed undo the two adjustmaent screws and turn it so that there is contact between 1 and 2 then lock it back up.

Matt