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wwest

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Everything posted by wwest

  1. If the lock solenoid does not fully extend then the controller will immediately unlock. Common problem, fix the solenoid or purchase a replacement.
  2. "Legacy" non-barrier A/C hoses DO NOT leak absent extreme high side pressures.
  3. No such thing as refrigerant leaks (strickly) due to "non-barrier" hoses....... My '92 R/awd Ford Arrestor, front + rear A/C, was just in the shop being converted to R134a refrigerant. Normal charge has been ~$160, this time ~$200.00. Difference was due to having to replace leaking o-rings on the rear of the Sanden compressor, something having to do with the refrigerant OVER-pressure relief valve. Say WHAT..?? According to the Ford factory manual if the refrigerant pressure rises to high then the valve opens to atmosphere to bleed off refrigerant, but then "resets", closes, to preserve the system integrity. But with the A/C compressor clutch controlled by a binary pressure switch why would the system ever go over-pressure? The answer would be an inadvertently overheated engine, cooling system, radiator, heating up the nearby A/C condensor and thereby raising the internal liquid refrigerant pressure. While I am by no means stating this as a definite answer for the reason our air-cooled Porsche's consistently lose refrigerant, it most certainly has a ring of truth to it. Drive our Porsche's HARD on a HOT day, making full use of the A/C, and now shut down the engine. How high would the pressure go in the rear lid condensor, overall high side, with all that engine heat rising up through the rear lid condensor. From what I could find on the INTERNET most automotive A/C compressors included an over-pressure relief valve, at least up until venting R12 to atmosphere was outlawed. Could this be the real, actual reason, our refrigerant charge only last 2 years? The stage is certainly correctly set.
  4. PSM is not simply stability control, it also includes traction control and "virtual" LSD functionality. Trac detects rear wheelspin/slip and INSTANTLY dethrottles the engine and will moderately apply brakes, ABS like brake modulation, if the condition persists. Winter tires often have a higher level of siping thus have less CSA for roadbed contact, additionally you mention they are narrower tires. All that adds up, for me, that Trac is activating.
  5. Why bother? What do you expect to gain? In any case the VC mostly remains flaccid, non-functional, due to Trac activation/intervention so you wouldn't be accomplishing much.
  6. Like most everyone else each spring I have to "top off" the refrigerant, now R134, in my '88 Carrera. A/C specialists have checked over for leaks many times in the past 16 years of ownership, and most recently when it was converted to R134 about 2 years ago. First, my theory, and then an explanation. When the car is parked with the engine and EXHAUST still HOT, convection airflow will HEAT the rear lid mounted condenser, likely very seriously so. How high might the resulting refrigerant pressure reach on a really hot, BRIGHT, day thrown in..? My pressure was at 65PSI this evening simply setting in a nice cool, ~55F, garage. Suppose, at the instant the ignition is switched off, part of the condenser, and all of the line to the recvr/dryer, and the dryer itself are FULL of liquid refrigerant, just as should be the case. The evaporator blower has also just been switched off reducing the heat exchanging capability of the evaporator significantly...AND...no compressor VACUUM. The high side pressure, LIQUID pressure, will now leak down VERY slowly. Might the high side pressure in that circumstance, BOILING whatever liquid might remain in the rear lid condenser, get high enough to begin leaking around the o-ring couplings...?? System leaks slightly, pressure subsides, until the next time. Anyone ever taken system pressure measurements in a situation as above. I'm thinking of revising my engine lid condenser fan system so it runs at half power with the engine switched off but with the high pressure compressor disable pressure switch open. Note: There is a REASON why my '01 C4 has an engine compartment cooling fan.
  7. The flasher relay in your 996 is already electronic. It uses a nichrome link to sense the current flow to the bulbs. If the current flow is low, indicating bulb failure, it goes into fast flash mode. Open up the relay and replace the sensing link with a 1 ohm resistor of 2 watts.
  8. Your priorities are seriously MISPLACED. Buy the best pads for BRAKING and spend the extra time cleaning the wheels.
  9. You should be aware that this is an extremely typical SCAM... You may be replacing two perfectly good parts. What tire shop..? Oh, your lifetime alignment package probably doesn't apply since you will be "intentionally" mis-aligning the car.
  10. No. The compressor shuts off if: The high side refrigerant pressure becomes too high or too low. WOT. The engine coolant "threatens" to rise too high. The cabin atmosphere reaches or is below the setpoint. OAT is below ~35F Evaporator surface temperature, close downstream airflow, is below 33F for more than 2 minutes.
  11. If you want more than 5-10% of the engine torque routed to the front wheels of a 996 or early 997 then the procedure is to drive agressively in a tight circle about 10 revolutions. With that much sustained disparaty between the F/R driveline rotation speed the VC will "stiffen" long enough for the average road course. The newest 997 now has an actual functional R/awd system using the same electromechanical clutch setup Ford has used, pretty much UNSUCCESSFULLY, in the Escape and Mariner. Now in use in the new FWD or F/awd 2011 Ford Explorer (yes, that says FWD & Explorer) but with water cooling of the PTO. With the C4S being R/awd the problems Ford has had are unlikely to affect the reliability of the Porsche version. Ford...STUPID...!!
  12. Thanks. It seems counter-intuitive at first glance, but now it makes sense. Anyway, I would think that the brightest combination would be a Red LED with clear lens, but would be more costly. You don't need diodes if you install LEDs in every socket in a given ciruit.
  13. Early Porsche C4 models using a VC, Viscous Clutch(coupling) have VERY little engine torque at the front wheel absent a SUSTAINED period of wheelspin/slip rear vs front. That level of sustained wheelspin/slip generally can only be attained with TC (PSM) off. The C4's additional traction capability is more often the result of rear engine weight bias rather than any significant level of VC coupling. That, of course, has changed now with the newer C4's making use of the Ford Escape electromagnetic clutch control technique.
  14. I am not holding out much hope if the Canadian dealers are as well informed (ahem!) as in the US. I doubt the lowering of the ratio of the lowest gear is more than 20% or so and that can't compensate directly for not having a 1:2 transfer case. On the other hand the new Tiptronics seems to be addressing low speed with a special pump to make sure the fluid pressure is high enough at low RPMs. One might hope that the viscous coupling could allow a very low speed crawl with enough torque to get over rocks or whatever. Haven't I read somewhere that both the 2011 997 C4 model and the Cayenne now use the electromechanical clutch as in the Ford Escape F/awd for coupling in the front drive, VARIABLY coupling...? So, i guess my real question is what does the new 2011 manual have to say about this. BTW, it is really a shame that these very off-road capable machines are mostly used to shuffle around the suburbs. A Shame...?? No, NOT, more safety aspects for them and YOU on wintertime adverse roadbed conditions. That's why the transfer case and the low range is being dropped from the product, 98% of the driver's have no need and the remaining 2% only have need rarely. Going off-roading, buy a 4runner...!
  15. Are you testing with or without ABS enabled...? The better the braking the more, quicker, ABS will intervene. The only valid comparison testing is with ABS turned off.
  16. Online..any US factory authorized sales agent, PU at factory.... Newer 997's have a REAL front drive clutch, DFI, and variable volume lubricating oil pump.
  17. If you have TC, Traction Control, then what you more likely than otherwise have is a "virtual" LSD. That's an LSD implemented via the use of braking to prevent wheelspin/slip.
  18. A failed, failing (intermittent) rear brake light will result in disabling the CC. Upgrading to LEDs, especially the high mount, will simulate an open brake light bulb/circuit.
  19. There is very little, of any, "incoming" airflow in the recirculate mode. The presumption seems to be that if recirculate is being used then any airflow reaching the evaporator has been filtered previously upon initial entry. I don't think many of us would have an alternative incoming airflow path open, window, ect, when trying to heat or cool the cabin.
  20. The cruise control system monitors the 3rd, high mount, brake light in order to cancel CC if voltage is applied. To check for circuit integrity there is a "keep-alive" resistor that always supplies a fixed level of current flow to the high mount bulb(s). So if the bulb goes "open" even momentarily that will be detected and CC will be disabled. The use of LED bulbs is now common but must be compensated for by used a parallel resistor of the correct size to simulate the actual incandescent bulb filament resistance which is VERY low prior to illumination, full 12 volt application. I used a 12 volt relay and a 50 watt halogen bulb to defeat the CC monitor. With the relay not energized the bulb is connected through the NC contacts but with relay activation only the lED bulbs remain in the circuit. If you replace burned out bulbs in the high mount brake light be sure to use the correct bulb wattage as replacements.
  21. Doesn't ABS pretty much "compensate" for additional braking capability...?? The faster the brakes bring the wheel/tire to the point of impending lockup the quicker ABS will activate to begin moderating, modulating, the braking HP. It would be better to simply find a way to disable ABS unless/until PSM indicates the need for allocation of more front wheel traction to directional control.
  22. "..during mild braking.." Wet, oily, roadbed, bumpy roadbed, railway, crosswalk paint stripping..?? ABS only kicks in, activates, when TOO much braking is being used for current roadbed traction conditions. But ANYTHING that results in a tire loosing contact with the roadbed during even light braking will oftentimes result in ABS activation. To help you maintain directional control during braking, any LEVEL of braking, ABS detects IMPENDING lockup by monitoring the rate at which end individual tire is slowing and if the computation indicates the tire will soon reach lockup the brakes are momentary released.
  23. First, the rain sensor results in the calipers getting a light, constant, precharge, so that shouldn't be the source of the pulsing. The "pulsing" you describe is the same feeling I get in our '01 F/awd RX300 when applying the brakes lightly in the wet and on a slight downhill incline. The dealer ascribed it to the EBD, Electronic Brakeforce Distribution, the automatic, dynamic, shifting of braking forces front vs rear to take optimal advantage of braking at both ends.
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