Poorly 16v 'clattering'

[bong69]

Hi all, here goes.....

Started the other day when I cleaned loads of gunk out of the airbox and put a new filter in, car was running pretty bad afterwards, looked at dizzy timing, mixture, cleaned out isv, replaced injectors, fuel filter and plugs, checked for air leaks etc etc but cannot suss it, am beginning to think its grim! Basically I have got the car idling ok now, and revs ok with the odd clattering noise at standstill, however when actually driving and accelerating the noise is terrible, its a metallic noise and seems to be coming from the top of the head, seems to kick in at about 2.5k and is in time with the engine, this car was a bit of a lemon when bought and looked like it wasnt maintained for years! Its done just over 200k too! Any ideas greatly appreciated, thanks

[bong69]

just a little update, wildly retarding the dizzy seems to cure it somewhat, infact revving in neutral its not there at all, will check belt and chain methinks! The airbox seems to make a bit of a racket too, bit like a hole in exhaust sound!?!

[Conker]

Maybe the plastic intake pipes are not sealed properly. Check from the throttle body back to the metering head. Another option could be you've massively upset the mixture when moving the metering head around.  See if adjusting the CO2 screw helps.

[jezza16v]

From your description of your problem and cure on retarding the timing it sounds like its pinking 'very badly'. Get the mixture & timing set up properly, very important on a 16v and make sure you use 98 ron fuel because it has no knock sensor. Putting a new filter in and cleaning all the gunk out is probably letting in much more air now making the mixture a bit weak. The engine will only 'pink' under load so revving in neutral will not cause pinking.

[bong69]

Great, thanks lads, theres hope yet!

[OakeyDoak16v]

Did you just say you replaced the injectors? What with, were they re-furbished or brand new? Or was it those Merc brass ones?
Baz.

[bong69]

am hangin me head in shame Baz.....they were straight from the scrappy  :embarassed:
BUT! if it makes any sense the car sounded smoother than it was before without them! The ones I took out looked like rusty old nails! Am gonna remove the airbox and metering head this mornin and mke sure its airtight and shipshape, if that dont make a difference i'll pull the rocker cover and see what awaits! cheers