fail to tick over

[Aki42]

 :lurk:just put another engine my mr2 mk111 starts ok but goes up to 3000 rpm then drops down to zero, it is hard to regulate with foot peddle any ideas whats wrong     aki42 

[dan944]

:lurk:just put another engine my mr2 mk111 starts ok but goes up to 3000 rpm then drops down to zero, it is hard to regulate with foot peddle any ideas whats wrong     aki42

Sounds similar to what happens when MAF sensor is dud or unplugged to me.

That's a stab in the dark though.

[Aki42]

new maf  plugged in no difference .secondhand throttlebody from dean of rutland     

[dan944]

Any EML?

[dan944]

Looks like idle air control valve or fuelling.

Did you take the IACV out when replacing engine?

[Carolyn]

I've found that, if a throttle body has been sitting unused for any length pof time, it will need a thorough cleaning before it goes back on.

Shnazzle also found this to be the case.

If, for instance, the butterfly doesn't close properly (because of a build-up of ally 'fuzz') the thing will not behave.  The same is true for the Idle Air Control Valve and the air passages that it uses.

There's info on the 'IAC' in the 'How To' section.

If you damage the IAC gasket (easily done) the Subaru one is the same! 

https://www.ebay.co.uk/itm/Genuine-Idle-Air-Control-Valve-Gasket-Fits-Subaru-Impreza-WRX-STi-00-07/272880450576?epid=2244355386&hash=item3f88f13c10:g:z4cAAOxyAc1SOyFY:rk:8:pf:0