I've been chasing an idle problem for a while. When it's cold. it idles roughly, and when it's hot it dies.
The engine is stock standard, and has done 150,000 k's. It is a one owner car I bought the a few
months back, and the problem came with it.
I've looked for vacuum leaks, and replaced and zip-tied all the vacuum hoses. Then I've done the
Compression test (All Good).
Injectors cleaned and reconditioned.
Injector insulators replaced.
Idle Valve Replaced.
Rubber couplings between TB and InterCooler and Turbo and InterCooler replaced.
Plugs, Plug Leads, Distributor Cap and Rotor Replaced.
Air Filter replaced.
Fuel Filter Replaced
Fuel Pressure Checked.
Different AFM tried.
Diagnostic Codes Checked - NO Codes
CLT Temp Sensor Checked - OK.
When the A/C is on, it idles better (doesn't die due to the idle-up), so I added an extra idle
adjustment by teeing an adjustable valve (sourced from a Camry) into the air line that
supplies the A/C Idle up.
This has fixed the idle in so much as it now idles reliably at whatever revs you set it at, hot or cold.
I've also tried adjusting the idle air bypass screw on the AFM, and this also stops it dying, but
the idle is not as steady as using the extra idle air valve, probably due to this adding air before the
TB, and the air valve after the TB.
The fact that introducing additional air has fixed it suggests that it is not a vacuum leak,
as what I've done is to effectively introduce air after the AFM, or the same as a vacuum leak.
Apart from this, it runs well throughout the rev range, doesn't overheat, run rich or any
other displays of bad manners.
Any suggestions gratefully received.
Edited by Stag76, 12 May 2014 - 02:06 PM.