What have I broken?

[Stu_HR]

Fitted new cam cover/inlet manifold/throttle body gaskets & new ribbed/V belts to my 97 2l 16v Ibiza today.
Bolted the lot back together & now the bl**dy thing idles at 1700 RPM & regularly pulses down to 1200 & up again.
Argggh!
If I disconnect the leccy connector to the idle stability valve the pulsing stops & the idle stays steady at 1700.

Search didn't turn up anything conclusive.
Help!

 

[cordobabrendy]

were the belts put back on properly?

 

[m0rk]

you have an air leak on teh manifold I'll bet.

check the wee nipple at the very back

 

[F2 Stu]

I concur, you may of put a split in it when you removed the pipe.

 

[Stu_HR]

Hmm... hose on little nipple looks OK. Engine stalls if I pinch the clothbound pipe & revs even higher if I disconnect it. On first starting the car revs to the usual 1100 & drops down to @ 800 but once you've touched the throttle it levels out @ 1700.
If the idle stabilisation valve is discconnected it stays steady at 1700. Connect the valve up & it regularly pulses from 1700 up to 2000. Fuel economy is unsurprisingly low.