hunting idle

[Kamatari]

so I\'ve got a idle problem s4 (uk 89)  where it won\'t idle low and if I do get it to drop to 1000 it then pulses between that and about 1400.

The screw on top of the engine under the rubber cap doesn\'t do anything when adjusted which if I\'m right would be a vacuum leak although I\'ve been spraying air leak detector stuff around and haven\'t found anything

 Ive checked my tps and its nearly right but slightly low on voltage but when adjusted it\'ll throw out either the closed or open reading (depending on what\'s adjusted) could this be worth changing?

Due to all this I would say my car runs very rich, now from what I\'ve read, I could adjust the idle fuel mixture screw but I have no idea what tool should be used to adjust it as it doesn\'t look like anything will fit it?

Any help would be much appreciated and if anyone has any idea how to adjust that screw, share the knowledge

[jamison1982]

im no expert but have u checked all the pipes as sounds like a leak ?

[Kamatari]

so far i havent found any leaks although im going to keep checking

[jamison1982]

Rats nest bud. Take off the plenum and check them all or simply replace them. I got loads of actuators and solinalds from reworxs for £2 each and changed then all. Or the pipe going to the map sensor. That\'s usually a prob.

Have u checked your maf ?

[gonzodave]

I had this on my fd turned out to be exhaust manifold gasket,kerim at powergains sorted out and did rats nest for very reasonable price.

[jamison1982]

Good point look at gaskets. Like the throttle body to manifold one. Had that go before and caused hunting idle.

[Kamatari]

Does anyone know where the "intial set connector" is on a UK rx7 fc? from the images ive seen on american cars i can\'t find the same adapter

[Kamatari]

Well I\'ve had another look and still can\'t find any leaks, I unplugged the bac valve and it didn\'t make any difference. I checked the voltage and its saying 12.5 ohms which is higher than what the haynes manual...so could this be the culprit?

[bumpstart]

UK cars have the fuel only ecu and so have a different ECU and wiring loom to the US/jap/aus s4

if you cant find the initial set connector ( Bb-14 ) [ a brown with red stripe ] go to the ECU and ground pins 2D and 3G together
( or just 2D to earth ,, as that is what 3G is )

else,, you calibrate the TPS using the no- coupler method,, engine off and measure the resistance to be less than 1 k ohm

if there is voltage bus issues where the orange volt bus wire at TPS is not fully 5V then i would expect that you need to adjust the TPS to lower than 1 k ohm to make up for the ....house loom

[bumpstart]

http://www.ausrotary.com/viewtopic.php?f=4&t=176914&p=2404282&hilit=set+connector#p2404282

note : the users here didnt get a result until they had brought the raw idle speed lower than 1000 rpm before the set coupler seemed to take effect and lock the timing

[Kamatari]

Thanks for the reply, currently ive managed to get the idle to about 1000 (although it pulses between that at about 1500

As for that initial set coupler, im pretty sure i havent seen one around as i\'ve tried looking in the past, i think its meant to be green? but do you know where it should be located? (its a UK car)

[bumpstart]

earth PIN 2D at the ecu
that means,, the 18 pin plug,, looking at the ECU , 2nd from right, bottom row
( should be brown with red stripe with brit ECU loom )

lower rpm to less than 1000 and the timing will lock and the idle control should stop interactions so that you can check it and set it

read the linked threads

at any rate,, just as easy to do the alternate method,, but do it with the engine warmed first so the wax cam doesnt play games with settings

[Kamatari]

Thanks for the reply

This might sound a bit silly but how would you go about earthing that pin? just to make sure i do it right

[bumpstart]

i would set it up a little more permanently by splicing to the wire,, adding a switch and earthing other end

but you can try just twitching the end of a fine wire into the back of the female loom plug

,,or you can by some fine pins used for board mount PCB in any electronics store to attach to the wire and push them into the back of the plug,, or cut the insulation and push it through the wire

[Kamatari]

Well ive tried doing the initial set and still cant cant sort out this idle i keep searching around for an air leak and spraying detector spray everywhere and can\'t find anything :@

i think i need someone to look at the car lol, anyone got any recommendations in the west midlands area?