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

Sun Sep 23 08:31:52 PDT 2007

Chris,

Thanks again.

I had already tried cleaning the MAF connectors with contact cleaner,  
although I just sprayed, I didn't use a brush. I suppose it wouldn't  
hurt to do it again.

I'll take a stab at your #1.

-Manny

On Sep 23, 2007, at 7:29 AM, chris chambers wrote:

> 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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>>>>
>>>
>>>
>>> Make April 15th just another day http://www.fairtax.org
>>>
>>>
>>>
>>>
>>>
>>
> ______________________________________________________________________
>>
>>> ______________
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>>
>
>
> Make April 15th just another day http://www.fairtax.org
>
>
>
>
> ______________________________________________________________________ 
> ______________
> Moody friends. Drama queens. Your life? Nope! - their life, your  
> story. Play Sims Stories at Yahoo! Games.
> http://sims.yahoo.com/