I think one of my Tip\'s has had it :(

[Prof]

I don\'t know if it\'s the same on the coupe\'s - I suspect it is - the ecu grounds onto the engine and the engine takes it\'s ground from the chassis.  Where the engine ground is - I noticed a lot of crap on the earth tag\'s - as Grinder says - earthing is a biggy for these cars - as the sensors all take their ground reference from the engine itself.
 
Others have found problems of hesitation and poor idle down to :
 

• Fuel pressure - check for leaks / check fuel pressure
• CAS sensor - Pete Taylor had issues with this - check the connector and unscrew the top plate and check all the teeth are intact.
• Spark plugs - dirt or fouled

[dthebuk]

I ended up taking the car to rotechniks who sorted it by playing with the tps some thermowax stuff? Think the egi\'s are extremely different though. As for the hesitation, that sorted itself out

[Adam fc]

I had my intercooler off today with the intention of finding the source of my bad idle but i have no idea what im looking at.

I understand that the TPS could be out and i could see two sensors with plungers acting on one end of the throttle assembly.

I could see various adjustment screws but without knowing which does what i wasn\'t prepared to screw anything up so i took a few photos to see if any of u guys could identify some of the parts.




Allso what is the spherical object above the throtlle cable?

[m1tch]

That object is the dashpot, its basically a damper for the throttle pulley so when you let off the throttle the last part of the throttle travel doesn\'t slam the intake closed, but closes it more gently, just smooths out the transition to idle

[Adam fc]

Oh right cool,im now not as lost when i look at my engine lol cheers

[Prof]

The screw you want isn\'t in the piccies.
 
If you look at the 2 plunger thingies - the grey/black rectangles - these are the throttle position sensors.  One is in contact the whole time, and covers the entire throttle travel - that\'s the wide one - don\'t touch that one
 
The other one - the outer one, is only in contact with the throttle mechanism for part of it\'s travel - that\'s the narrow one - the one you adjust.  Underneath the narrow range throttle sensor and visible from the front of the car with the stock intercooler off, is a screw about 1 inch long with a spring on it. It adjusts the narrow range tps \'home\' point.
 
Don\'t forget - it needs adjustment when the engine is fully warm - if you note the positions of the throttle in relation to things when it\'s cold, and then again after the engine has run - you\'ll see they change. :Thumbs-up

[L18M]

would adjusting the bac valve help with the idle?

[Adam fc]

righty ho ill attack it tomorrow with her warm and see if will make any difference.

This all helps to narrow the problem down.

[Adam fc]

found this link regarding BAC valve cleaning.

http://www.1300cc.com/howto/how2/bac.htm

[Adam fc]

Well I\'ve managed to sort my crap idle.It turns out it was the throttle cable was really slack so once I had tightned it up so there wasn\'t any slack the 3000rpm warm up started to work again and any surging in the revs at idle have gone.

My car allso suffered from bad juddering off the throttle which has now all but gone.
I had a quick fiddle with the narrow range tps which has allso smoothed out any small lumps in the idle.
Cheers for the advice chaps as it\'s a small step in the right direction to having my car running as it should.

I allso managed to do a compression test and it returned with 6.0bar even on all chambers.
Is 6.0 bar fairly good for a turbo 13b or should I start saving for a rebuild lol?

[Prof]

I allso managed to do a compression test and it returned with 6.0bar even on all chambers.
Is 6.0 bar fairly good for a turbo 13b or should I start saving for a rebuild lol?

Any idea what RPM you had during the compression test ?
 
8.0 BAR is excellent (new engine), 7.0 BAR is good, 6.0 BAR ok but getting tired, 5.0 BAR - expect starting problems and an imminent rebuild.
 
But these readings are based on a test at 250 RPM.  There is a graph in the Service Manual - that shows how to factor up the readings to 250.  Basically - a reading of 5 BAR at 200 psi is the same as 6 BAR at 250.  This means if you\'re revs were a little down during the test due to a tired battery or starter motor, the readings may be better than 6.0 BAR.
 
The main thing is that they are even - which is a good sign.