weird rocco happenings (part deux)

[amalventano at sc.rr.com (Allyn)]

ok, so last weekend i did the gunk engine brite all over the engine bay 
treatment, followed by hosing the crap out of the engine bay (with engine 
running), hoping to agitate whatever fault there may be. not a single 
flinch, despite drenching everything with the nozzle set on 'jet'. i did 
some cheezy checks of the idle switch (note: if its stuck open, it makes the 
idle high, not low), and some other under-hood checks. came up empty.

...and everything was fine all of this week (i drive the rieger 30 mins to / 
from work daily).

then today i got the same cut-out. happened while coasting in gear (again). 
hit gas, nothing. cycled neutral, attempting roll-start - nothing. cycled 
key - voala, back in business. 10 secs later it does it again, this time i 
stop and restart engine - starts again, no problem. it does it once more, 
but this time as im coasting with it floored, it pops back to life out of 
nowhere.

i deduce the following on the rest of the trip home:
- happens while decelerating - possibly electrical in engine bay caused by 
engine torquing forward, or something electrical that is sensitive to 
deceleration. (problem never happens while on throttle, no matter how much 
throttle - trust me :).
- comes back after messing with key - possibly something with ignition 
switch.

after pulling into the driveway i turn the engine off, then turn the key 
back to ignition and slowly figit with it towards the off direction. i hear 
a click come from the fuse panel, but the ignition is still on. turn key cw 
again (still in 'on' position), and get another click. i can now cycle the 
key back and forth about 10 degrees and i'm causing 'some' click from the 
fuse panel. i figure this is my problem, so i start the engine again and do 
the same cycling of the key. the clicks continue from the fuse panel, but it 
has no effect on engine idle at all (weird, i thought it was the fuel pump 
relay that was clicking). turn off engine and fiddle with key while checking 
relays. turns out its the load reduction relay. i'll admit, im weak on what 
load reduction is supposed to do, but i can say now it has no effect on the 
idle. question is, could it result in engine cut while driving?

any other ideas, please dont hesitate to throw in your $0.02
Al

Allyn Malventano, ETC(SS), USN
87 Rieger Scirocco GTO 2.0 16v (daily driver, 200k, rocco #6)
86 Kamei Twin 16V Turbo Scirocco GTX (30% complete, rocco #7)
86.5 Occo 16v Trailer (rocco #8)
90 Passat GL 16V (the wifes new daily, 200k)


----- Original Message ----- 
From: "Allyn" <amalventano@sc.rr.com>
To: "scirocco list" <scirocco-l@scirocco.org>
Sent: Friday, April 16, 2004 6:55 PM
Subject: weird rocco happenings


> ok, so im on the way back from kill bill 2 (most excellent, btw).
>
> take 26 home, and put the rieger into a 1.1g drift along the exit ramp
> (right bank).
> i bask in the sounds of sliding kumho and occasional per-clunks of loose
> objects finding their way to the driver side of the beast.
> end of ramp, no power, absolutely none. no warning lights (still in gear,
> engine still turning). as i am slowing, i figure i caught some water in 
> the
> fuel suction, but this is unlikely (right turn, not left, and i am at 3/4
> tank, and i took care of that water problem weeks ago).
> i coast further, figuring whatever it is will pass. i keep the gas 
> planted.
> still nothing.
> hit clutch and let it die. cycle key. start. cranks right up.
> drive 2 blocks to turn right into neighborhood. hit clutch as i slow for 
> the
> turn. engine dies. i notice the sound of a relay clicking a couple of 
> times
> as i cycle the clutch to try and roll-start. my guess is it was the fuel
> pump relay responding to ignition pulses (an expected action).
> roll-start successful as i accelerate out of the turn.
> go couple more blocks, slow for left turn, engine dies again. roll start 
> out
> of turn - again successful.
> carefully make last turn to house street. this time i stay on the gas and
> keep it in gear. no issues, but the engine doesnt 'feel' as happy as it
> usually is.
> i carefully keep the gas on as i drop into neutral and e-brake to a stop 
> in
> the driveway. once stationary, i slowly let off gas to see what the deal 
> is.
> idle slows to a very slow crawl. its a stumbly idle. firing on all
> cylinders, no missing at all, but its a slower idle (~600), and its 
> stumbly
> because of it.
> pop hood, everything looks good. do the obligatory check of the idle speed
> set screw - right where i left it. wiggle various connectors, no effect. 
> do
> quick cursory checks for vacuum leaks - nothing. plug wires look good. no
> leaks anywhere. wife comes out to see whats up. i chat while doing further
> inspecting. finally i end up grabbing the throttle body and give it a 
> couple
> of good blips. after the revs, engine returns to a perfect purring idle. i
> mess with it more, but cannot get it to return to its crappy idle.
>
> notes:
> - first time it died, i believe i had tach indication, and i believe the
> fuel pump was running, yet engine did not return to running condition
> depsite coasting at 4k rpm with ignition still on. despite this, it 
> started
> just fine after the engine was allowed to stop.
> - cause is likely linked to what made the idle crappy, but that doesnt 
> make
> sense.
> - it appears the fault is causing the low idle speed, and its also causing
> undershoot of idle if returning from revs, resulting in engine stall.
>
> ideas?
>
> thx in advance for pondering / suggestions
> Al
>
>
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