i have a saph 4x4 cosworth which has a few bits on it including greens, 3 bar, t35, not sure of the internals of the engine as i bought it as it is. the problem is that it wont idle below about 1600 revs, i have checked for air leaks, i have cleaned the idle speed control valve and still no joy. also when starting the car sometimes it will just not fire until the 3rd attempt of turning the key but then will start instantly. and it isnt very good at running from cold.
any help would be greatly appreciated.

mike

 

CTS sensor, check first it's plugged in.
Disconnect the ISCV and see what the idle does, set it to 850 rpm, with HOT engine and NO LOAD, ie lights etc off, check for any obvious obstructions like a tight throttle cable, or sticking flap etc at the same time.
You need to check the CO should be around 2 - 2.5 % CO.
It sounds like someone has been tinkering before you, a huge amount of people turn the CO screw to try to cover up for other faults like a duff CTS.
It would be a good idea if you do not know when it was changed to change the CTS, only 10 minutes and Ł10 or so.
I get mine from MATT LEWIS 01922 692424.
tabetha

 

Temperature sensor ? Although that's usually related to difficulty starting when warm and running too rich iirc.

The correct procedure for doing this is to use the idle screw which is just under the front of the throttle body (easiest to get to if you remove the hose between intercooler and throttle body.

Do not (as I have done in the past), use the adjuster on the throttle cable to set your idle

PS: There is a high likelyhood that the screw will be jammed solid and may need a little persuasion before you can turn it (old cars for you).

Good luck.

 

DO NOT UNDER ANY CIRCUMSTANCES SET THE IDLE WITH THE INTERCOOLER TO THROTTLE HOUSING PIPE DISCONNECTED, it needs to be set with this connected as this is how it will be idling normally, it in all likelyhood won't make much if any diffrence, but it is so easy to do with it still connected as I do all the time on these cars, just use a "STUBBY" on the screw, and a "STUBBY" spanner to undo nut, as said can be well tight.
tabetha
ps the reason I do disconnect is because 1 there is no need, 2 it stop unfiltered air getting into engine, why we spend money on decent air filters.

 

Indeed, I meant that removing it would help find the screw in the first place