[s-cars] Drastic Power Loss-So far No Joy

Sun Sep 23 04:29:30 PDT 2007

I have two suggestions:

#1 If it is overboosting OR the ecu "senses" it is overboosting the ecu
will cut off the fuel by shutting off the fuel pump relay. I suggest
you
remove the fuel pump relay and put a jumper in place. If it is sensing
an overboost situation this should keep the fuel flowing and stop
the drastic power loss. 

Or you you can leave the relay in place and run wires from the socket's
feed to the relay to a bulb you can see (on the dash?). This way if the
fuel is cut off should see the light go out.

#2 I had this same experience with my S4 a few years back, solution
was to purchase electrical contact cleaner and a small brush and clean
the contacts on the MAF cable.

Hope this helps
Chris 

--- Manuel Sanchez <manuelsanchez at starpower.net> wrote:

> 
> Chris, didn't see any obstruction in that WGFV to Wastegate line. We 
> 
> pulled it and swapped components from another UrS and had the same  
> cut-off result.
> 
> We also tested the wastegate diaphragm with a vacuum pump, and it  
> held the pressure.
> 
> We are also planning on seeing what the fuel pump is doing at the  
> time of cut-off as Stott and DJ have suggested.
> 
> Taka, after further investigation I've discovered that only the  
> resistance/continuity was checked on my WGFV. I have a new stock WGFV
>  
> on special order. Haven't tried just disconnecting the WGFV and  
> plugging the line on a test drive yet either.
> 
> Thanks again to all of you for the suggestions and experiences. If  
> you have anymore, please send them my way.
> 
> Regards,
> 
> -Manny
> 
> 
> 
> 
> On Sep 21, 2007, at 9:24 PM, chris chambers wrote:
> 
> > This may be out in left field BUT...
> >
> > I have heard of some "tuners" putting a ball bearing in the line
> > from the WGFV to the Waste gate. IF this is the case OR there is
> some
> > other obstruction in the line it can lead to overboost.
> >
> >
> > right?
> >
> > HTH
> > Chris
> >
> >
> > --- Manuel Sanchez <manuelsanchez at starpower.net> wrote:
> >
> >> S-heads,
> >>
> >> Still hunting for whatever is causing my drastic cut off of power
> >> near peak boost. This happens with my MRC RS2 software in my ECU
> as
> >> well as with a bone stock ECU. So with my RS2 ECU I hit the wall
> at
> >> about 26-27 psi, when the Stock ECU is installed (with the stock
> >> injectors) I hit the wall at about 13-14 psi.
> >>
> >> Many of you have suggested I'm experiencing an Over Boost
> situation
> >> and have given me some avenues to pursue, here's what's been done
> >> today:
> >>
> >> 1. My RS2 WGFV
> >> Checked with a multimeter, and it's within spec
> >>
> >> 2. Other used, Stock OEM N75 WGFV
> >> Checked with multi-meter, within spec
> >> Installed in my car, test drive results in the drastic cut off in
> >> power (nuts)
> >>
> >> 3. Inspect Wastegate Diaphram
> >> No tears are apparent. Will test vacuum on this tomorrow
> hopefully.
> >>
> >> 4. Turbo Outlet hose and Wastegate hose (that small diameter
> crinkled
> >>
> >> and ultra expensive bugger).
> >> Swapped these hoses, as well as this other stock N75 WGFV into my
> >> car, same boat anchor results
> >>
> >>
> >> Some people have suggested the altitude sensor, hopefully I can
> check
> >>
> >> that soon.
> >>
> >> What's puzzling, is that I think many of these electronic items
> would
> >>
> >> throw a code if they were malfunctioning, no? Previously the only
> >> codes I had been receiving were :
> >>
> >> 00537 – Oxygen Sensor Control
> >> Maximum Control Level Exceeded
> >>
> >> Condition:
> >> Fuel Tank Low resulting in fuel system pressure less than 3.3 bar
> (48
> >>
> >> psi) [Note tank was ¾ full as indicated on fuel gauge]
> >> Ignition System Failure
> >>
> >> Symptom:
> >> CO before 3 way catalytic converter less than 0.5% (Hmmm, what
> could
> >>
> >> this mean???)
> >> Fuel Consumption high
> >>
> >> Repair:
> >> Fill Fuel Tank (tank had plenty of gas, and fuel gauge reads
> >> accurately)
> >>
> >> 00537 – Oxygen Sensor Control
> >> Minimum Control Limit Exceeded
> >>
> >> Condition:
> >> Engine Intake Air Leak after Mass Air Flow Sensor-G-70
> >> Leak in Exhaust System in front of 3 way catalytic converter
> >> Heated Oxygen Sensor (HO2S)-G39-malfunctioning
> >> Fuel System Pressure greater than 4 bar (58 psi) [This is
> >> interesting, seems like I will throw this code all the time if I
> set
> >>
> >> the Fuel Pressure to 4 Bar/58 psi, which is what I believe I’ve
> been
> >>
> >> told is the Fuel Pressure for RS2’d cars. True?]
> >>
> >> Symptom:
> >> Rich Exhaust
> >> Spark Plug Fouling
> >> CO before 3 way catalytic converter greater than 3%
> >>
> >> Repair:
> >> Repair Leak
> >> Check HO2S-G39
> >> Check Fuel System Pressure
> >> 00561-Mixture Adjustment
> >> Adaptation Limit (mul) exceeded
> >> Condition:
> >> Fuel System Pressure too low
> >> Spark Plugs, ignition coil, ignition coil power output stage
> >> malfunctioning
> >> Symptom:
> >> Reduced Fuel Economy (no kidding)
> >> Sooty Exhaust (yeah, in spades)
> >> Repair:
> >> Fill Fuel Tank
> >> Repair Leakage
> >> Check Fuel System
> >> Check Fuel System Pressure
> >> Check G70 (Mass Air Flow Sensor) [We cleaned the OEM MAF with MAF
> >> Cleaner, and we also installed a brand new RS2 MAF-we still had
> the
> >> drastic engine cut-off]
> >>
> >>
> >> Lately  we've been thinking that whatever the fault is, it's
> >> something mechanical as opposed to electrical (that would throw a
> >> code).
> >>
> >>
> >> Some people have suggested  a few things that we haven't had time
> to
> >>
> >> try yet:
> >>
> >> Altitude sensor
> >>
> >> Check the wiring between the MAF and ECU with an ohmmeter
> >>
> >> Throttle Position Sensor - the ECU allows boost only when the
> >> throttle position sensor is above a certain value. So you could
> check
> >>
> >> the sensor
> >>
> >> Light on the fuel pump to see if it's getting cut off when the Cut
> in
> >>
> >> Power occurs (I'm not exactly sure how to rig this up actually),
> >>
> >> Hopefully I can check these soon.
> >>
> >>
> >> Any other ideas are greatly appreciated.
> >>
> >>
> >> Thanks.
> >>
> >> -Manny
> >> 95 UrS6 (still kickin my arse)
> >> _______________________________________________
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> >> S-CAR-List at audifans.com
> >> http://www.audifans.com/mailman/listinfo/s-car-list
> >>
> >
> >
> > Make April 15th just another day http://www.fairtax.org
> >
> >
> >
> >
> >
>
______________________________________________________________________
> 
> > ______________
> > Moody friends. Drama queens. Your life? Nope! - their life, your  
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> > http://sims.yahoo.com/
> 

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____________________________________________________________________________________
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