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stubborn rieger / engine problems (update #3 - dpr wanted)



Youre DPR should never be 0. That would be full rich, as in no air, just
fuel. Are we talking about the same mixture test here? I think youre DPR
or your O2 sensor has taken a dump. I wouldn't eliminate giving the
transfer pump a good whack to be sure you don't have any crap in it. I
treat my transfer pump like a old black and white TV.=20

http://www.scirocco16v.com/tech/fuel_mixture.htm

Shannon=20

-----Original Message-----
From: Allyn [mailto:amalventano1@comcast.net]=20
Sent: Sunday, April 28, 2002 5:27 PM
To: scirocco list
Subject: Re: stubborn rieger / engine problems (update #3 - dpr wanted)


Disregard the oxs being bad. i had the meter on wrong. connected
correctly i get .1v when first started, steady rise up to ~.8v when the
oxs is warm (after ~ 1 minute).

OK, here we go. Ran the meter around and into the car so i could get a
reading of dpr current with the car on the road. After starting i get 10
ma which settles down to 0 ma after a minute (just like before). Under
full throttle acceleration i get ~+15 ma. While coasting down in 3rd
from about 4k rpm i get the -53 ma that im supposed to get (coast down
fuel cut), but whats weird is that i dont get the increased
decelleration from the engine. Its as if the dpr is getting the current
to cut fuel, but it isnt doing so. I also have a feeling that its
running rich (getting puffs o fuel if i rev it when its hot). This kind
of jives with the dpr going to 0 ma when it idles in closed loop. 0 ma
means the cis-e box is trying to reduce fuel flow as much as possible
(but the dpr isnt actually doing what its supposed to, especially if its
just wide open).

*note* the fuel distributor on this car is about 1 year old (but the dpr
may have been taken from the old one and put on the new one when it was
swapped).

Now, who has a 16v dpr lying around?
Al

Allyn Malventano, ETC(SS), USN
87 Rieger GTO Scirocco 16v (daily driver, 170k, rocco #6)
86 Kamei Twin 16V Turbo Scirocco GTX ('it has begun', rocco #7) 87 Jetta
8v Wolfsburg 2dr (daily driver, 260k, 0 rattles, original clutch,
driveshafts, wheels :)


----- Original Message -----
From: "Allyn" <amalventano1@comcast.net>
To: "scirocco list" <scirocco-l@scirocco.org>
Sent: Sunday, April 28, 2002 6:47 PM
Subject: Re: stubborn rieger / engine problems (update #2)


> did some more testing:
> (following tests done at the cis-e box connector)
> - throttle body wot and closed switches: good (~1 ohm closed)
> - coolant temp sensor: good (abt 1.4k when cold, was abt 200 ohms when

> hot)
> - air flow plate potentiometer: found intermittent contact along its
range, particularly in the 2k
> ohm range (full range is 1k to 5k). Disassembled and cleaned
potentiometer. Reassembled and
> retested, good movement through range. Went for drive: problems still
exist.
> - dpr current: with engine warm and ignition on i get 10 ma
(expected). shorting the o2 sensor
> 'green wire' (heater) to ground results in a steady rise to 20 ma over
a 20 sec period (expected).
> start engine, check meter, steady at 10 ma (expected for post start).
Over 1 minute period dpr
> current drops stradily to 0.0 ma and stays there (it should begin
fluctuating in closed loop, not
go
> to 0 and stay there, this is a problem). Rev engine and snap throttle=20
> closed: current snaps to -50 ma and back to 0 when returns to idle=20
> (expected, but should be returning to fluctuating current,
not
> 0).
> - check o2 sensor resistance: 6 ohms. o2 sensor voltage: 0 volts with=20
> engine running (what should
i
> see here on a good o2 sensor?).
>
> ** what equivalent o2 sensor can i get that will replace a 3 wire on=20
> our cars? i heard something about a mustang one or something a while=20
> back... ***
>
> Thanks in advance,
> Al
>
> Allyn Malventano, ETC(SS), USN
> 87 Rieger GTO Scirocco 16v (daily driver, 170k, rocco #6)
> 86 Kamei Twin 16V Turbo Scirocco GTX ('it has begun', rocco #7) 87=20
> Jetta 8v Wolfsburg 2dr (daily driver, 260k, 0 rattles, original=20
> clutch, driveshafts, wheels :)
>
>
> ----- Original Message -----
> From: "Allyn" <amalventano1@comcast.net>
> To: "scirocco list" <scirocco-l@scirocco.org>
> Sent: Sunday, April 28, 2002 4:20 PM
> Subject: stubborn rieger / engine problems
>
>
> > My string of good luck has ended.
> > Problem: (noticed increased random missing when hot at idle over=20
> > past few weeks). Car ran fine,
> then
> > sputtered under acceleration (as if one cylinder wasnt firing).=20
> > During this minute it only
missed
> > under load (revs freely when not loaded, no misses). After ~1 minute

> > the sputtering went away
but
> > there was a noticable (not major) loss of power under load. The loss

> > of power doesnt seem to be
> from
> > any one cylinder. Car is still drivable. Revs freely as it ever did=20
> > with no misses. The next
time
> i
> > drove it, i had the same power loss, but noticed a sputtering that=20
> > occurs only when coming off
the
> > throttle (under load). No sputtering occurs under acceleration, only

> > the slight power loss.
Engine
> > coasts down cleanly when off of pedal (no sputtering). The sputter=20
> > only occurs under partial throttle and especially when coming off of

> > full throttle. Still no stuttering while free reving.
> >
> > What was done so far:
> > Change plugs: no effect (old plugs were clean, all 4 looked=20
> > identical, no sign of plugs being cause). Remove/inspect plug wires:

> > (neuspeed wires), all wires had consistent resistance, even with
wires
> > wet.
> > Swapped coil with another one: no effect, same exact symptoms.=20
> > Checked ignition timing: Dead on, no adjustment necessary. Checked=20
> > cam timing: dead on. *at this point i let the engine idle up to=20
> > temperature and noted no missing at all, i can only assume the=20
> > missing problem was corrected and is not related to the sputtering=20
> > problem*
> >
> > Please let me know any opinions/thoughts. My hunch is possibly=20
> > something fuel related or perhaps something funky with the coil=20
> > driver.
> >
> > Allyn Malventano, ETC(SS), USN
> > 87 Rieger GTO Scirocco 16v (daily driver, 170k, rocco #6) 86 Kamei=20
> > Twin 16V Turbo Scirocco GTX ('it has begun', rocco #7) 87 Jetta 8v=20
> > Wolfsburg 2dr (daily driver, 260k, 0 rattles, original clutch,=20
> > driveshafts, wheels
:)
> >
> >
> > _______________________________________________
> > Scirocco-l mailing list
> > Scirocco-l@scirocco.org=20
> > http://neubayern.net/mailman/listinfo/scirocco-l
>
>
> _______________________________________________
> Scirocco-l mailing list
> Scirocco-l@scirocco.org=20
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