irratic idling

[RobW]

I recently changed my 16v engine and have just finished wiring it all up.when i start it up,it idles at 3000 rpm and doesnt ever go down!ive checked all the hoses and sprayed the idle control valve etc,but no luck.has anyone got any advice they could give me?

 

[BenR]

check for an air leak on the manifold?

 

[JAY172]

as above and have you touched the throttle potentiometer? check all manifold hoses are refitted(breather pipes etc) and the condition of the map sensor+its connector.

 

[RobW]

ive checked for air leaks,doesnt seem to be any.i took one of the pipes off today,i think it was the one from the idle valve to the inlet manifold.when i blocked it with my finger,the revs would drop alot.anyone know what that could mean?

 

[weight]

any chance of borrowing another icv?

 

[JAY172]

drop a lot or virtually cut out.when you watch inside the idle valve as you switch on the ing and start the engine you should be able to see the internal shaft move as it will close to bring down engine rpm(if you can see down the holes and see it that is).if you can see the shaft and it doesnt move its probably seized or has an internal electrical fault.

 

[BenR]

the engine should almost cut out if you block the ICV pipe.

 

[JAY172]

as i said.if it virtually cuts out then thats the problem but if it still idles pretty high with the idle valve blocked off then there must be an air leak somewhere else.

 

[BenR]

spray some wd40 or better, some bradex easy start around all joints, when the rpm picks up youve found the leak.

 

[RobW]

the engine will cut out when i put my finger over the pipe.i swaped the idle valve yesterday with the one off my old engine but it is still the same.

 

[RobW]

I managed to sort out my idling,i turned something inside the idle valve and then put it back on and it seemed to idle ok then.

 

[JAY172]

maybe the valve had got jammed somehow then.