Hi all have just had my 86 rs cosworth rebuilt was running stage 3 changed injectors to blues as was running greens but car is reluctant to start it starts and runs for a second or so please help with any tips ,are there any cut outs like in the saphire boot petrol cut off switch,should i install a standard or stage 1 chip into the ecu there is electric and petrol getting to the engine

 

Put the engine to the spec that matches the chip. If it's a chip for greens, and you replace them with blues, then you'll not inject as much fuel as the ECU is expecting, so of course it won't run right.

If the engine still won't start, give us a bit more of a hint as to what is happening.

I presume you've plugged in the water temp sensor at the back of the head on the inlet side (blue 2 pin sensor), and plugged in the map sensor? Similarly, have you accidently swapped around the plugs for the crank sensor and the dizzy phase sensor?

 

As said put the greens back in, why did you feel the need to try to destroy your brand new engine ?
The blues flow MORE fuel at a given cycle than the greens so will be exceptionally rich, and most likely fouling the plugs.
Make sure also the phase sensor is timed up 100% in addition to the excellent advice given by jon@work.
As he rightly points out a chip goes with a certain colour injector, you cannot mix and match!!
tabetha

 

as above.

you have to make sure you keep the spec the same.