Fuel traces in EGR Valve.

[fixkick]

Hello again!
Due to some RL issues I had not much time to spend on my car (sadly)...but I've done some work on her...

PROBLEM:
- Fast idle at cold starts is dead. Just goes from 400 to 900-1000rpm in 2seconds. But it start at 1st try.
 Then I hear the engine "trying" to rise in rpm with no luck...(rpm sound is like increasing and decreasing. just a bit, the rpm indicator cant recognize it but I can simply hearing the engine noise)
- when hot, the idle stick at 900/1000rpm. If I give gas then changes to 800-850 (all accessories off) this is normal I think. but only in Europe. (idle rules hot ,slightly different there)
- Engine shakes quite badly when at IDLE. Hot or cold is the same. Seems like is misfiring... this is misfire.
- after driving, if I stop (engine still running) rpm stuck to 1500 for like 10sec. then 850rpm idle. This occurs sometimes not always... (ISC sticking>?

WORK DONE:
- new rotor cap.
- new sparks (NGK BPR5ES)
- new spark wire (NGK blue)
- new exhaust mainfold with gasket (the old one was cracked)
- cleaned the whole TB
- cleaned the ISC valve and tried another one (but nothing changes)
- checked for valve lash (0.15mm in and 0.19out)
- dashpot seems ok
- all hoses replaced (just to be sure)
- EGR valve closed (with a plate)
- new fuel tank (the old one was full of rust)
- new fuel pump (the old one was gone...) + fuel filter
- engine mounts are quit new (1yr old)

Best regards!

GREETINGS TO YOU: and a lot of hard work you did, there, and all good work.

Just goes from 400 to 900-1000rpm in 2seconds. (this  is what is called IDLE HUNTING or IDLE SURGE (not sure in Italian me? but for sure you are welcome here)

when any 8valve engine hunts that means you have air leaks, 400 to 900 is 500 rpm HUNT, SURGE.
The ECU does that  (via ISC top right side of TB) hunting trying hard to get idle to correct properly.
Top cases of hunting are vacuum leaks, and are hard to find but can be found.


the big clue is MISFIRE>  the engine fueling is wrong for some reason, and is running very rich.

• idle controls will fail if the engine is MISFIRING , idle controls are the last thing to work correctly 400RPM is crazy wrong,  until fuel and spark are good.
  
• Is engine compression reading good 150PSI x 4... (10.4 Bar or ,1040 KPa.)
  
• Is spark timing correct?
  
• is the injector cleaned ? (remove and cleaned with ultrasonic cleaner? , if fuel was bad or rust this injector will fouled up)
  
• Is fuel pressure at SPEC?
  
• Does the ECu flash code 12 (good) on demand? 'Diagnostic jumper clip/wire"
  
• Does misfire get better or end with 02 (lambda) sensor is unplugged,? oxygen sensor)
  
• When the TB was removed was the TV throttle valve closed 99.9% (.0005 gap. 0.125 Millimeters, aprox.  so close water fails to pass? the gap)
  

Im am guessing but the 400 RPM will be gross rich (fllodding) misfire, and spark tops look wet with fuel,
does the injector leak, if 2 persons:
1: one at key, turns off running engine,
2: 2nd person looking down air horn of TB and at inject in front if eyes, person to turns key off and person to sees inject stop fuel dead, instantly?


testing at #2
this engine runs ok with the air horn pipe removed from top of TB (left and right large pipe) just  know that backfiring engine is present can burn eyebrows, ok?>
due care, during this test.
This one injector may be in bad shape from bad fuel.