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1999Porsche911

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Posts posted by 1999Porsche911

  1. What is your oil pressure on a fully warmed engine at idle. I suspect it is too low and the simplist way of fixing it is to move to a higher viscosity oil. IMOAE, you should never run Mobil's 0W40 in you car regardless of how it sounds. There are too many oils available that are far superior to that oil.

    Other possible causes are an electronic tick casued by a bad coil or cable or the normal operation of your EVAP canister purge valve which can sometimes be quite loud, a bad belt or pulley.

  2. Do you really think the engine needs more air or a new airfilter?? Nope! The computer will only let so much air in. Plus the fact of running an airfilter flush with oil. Not on a Porsche motor. I run the KN on my atv's. No issues with ATV's. The Porsche motor is dialed in. It needs :rolleyes: nothing. You're wasting your time and asking for problems!!! Just my take. E

    The computer has no control over the amount of air that gets to throttle body.

  3. Maybe a great read, I just finished, but totally, TOTALLY idiotic.

    The sole control of A/F mixture during engine idle or "cruise" is left to the upstream oxygen sensors, closed loop. During these periods, mixture STRICKLY controlled to stociometric, the MAF/IAT signal levels (now operating under known, controlled, intake airflow conditions) are "captured" for later use filling in a parametric mapping table to be used under/with higher engine load/loading conditions wherein the mixture MUST be enriched beyond the measurement capability, range, of the oxygen sensors.

    The MAF/IAT module/assembly is only able to measure the actual intake airflow volume/rate in a very small area of the intake airflow path, a snapshot, if you will. So the overall, total intake airflow volume must be calculated from that rather small sample. Add a CAI, Cold Air Intake, ANYTHING that impacts the calculation of intake airflow volume and the factory parameters used to facilitate the intake airflow volume from the small (area wise) sample might become USELESS.

    Like the clock fully stopped only being correct twice a day, your A/F mixture will only be "correct" for engine idle or cruise periods.

    Oh, since other than at WOT times the throttle plate constitutes the primary restriction then any intake airflow modifications that impact flow volume will have little or no adverse effect except at or near WOT.

    Just what yawl needed to hear, right..!!

    And what happens during closed loop when the MAF is reporting substantially incorrect flow numbers? O2 sensors can only adjust so much, BTW: The MAF itself is little more than a set of resistors housed in a nice expensive piece of plastic. The only difference between the 996 and the TT MAF is just a different set of resistors. The MAF signal is important in both open and closed loop operation.

  4. Most engines will have valve tick if they have been sitting for a long period of time, regardless of what oil if used. It can be worse and more frequent in those engine that are not driven for long period of time after warm up as the moisture in the oil can oxidize inside the lifters and cause them to temporarily stick even when oil is getting to it. Moisture can also bind the valve in the sleeves. If the tick does not go away within a few seconds, sometimes shutting the engine down for a few minutes and restarting will correct it.

  5. Voltage for your O2 sensors can range, and should range all the way to 0.90+ volts. At WOT, even tho your O2 sensors do nothing to control fueling, your after cat sensors should rise from low 0.80 to 0.90 volts indicating proper a/f ratio. However, just because they might not have the proper readings, does not, and is most often not, an indication of bad O2 sensors. Your reading of 18 kg/hr indicates that the air mass value of the MAF at idle is correct.

    P1126 indicates a lean condition. Remove your idle control valve and clean. Check for air leaks in the intake AFTER the MAF sensor, vacuum lines and throttlebody bolts as well as oil cap. Leaks in the exhaust before the primary O2 sensor can also throw this code as will low fuel delivery caused by low pressure or fouled injector(s).

    If you have done any mods to the car and moved or played with the sensor wires, check them for kinking or stretching or damage. The sensor wires are as critical as the sensor is since the wires are used by the sensor to breath.

  6. 1999Porsche911, what switch did you use, anyway to make a illuminted one work?

    I don't think you can use oem switches, you will have to keep your finger on it, you would need a relay to make it hold.

    And for the radiator relays, Its one wire on each relay(ground pins), linkin together then going toward switch, right?

    or different switches for both?

    thanks

    If you use the Porche swtiches you will need to install a self locking relay inline that will toggle on off each time you press the switch. I simply installed a 2 toggle switches in the batwing on the console, 1 for both radiator fans and 1 for engine compartment fan.

    You are correct to tie the 2 ground wires from the fan relays together and connect at 1 switch.

  7. Radiator Fan and Engine Compartment Fan Switch Mod

    The 3.4 996 runs extremely hot when driving around town in temperatures higher than 75 degrees. This mod is a way to reduce coolant temps back to a safer level, helping to reduce oil temps and improving performance.

    The mod consists of installing a switch that will allow you to turn on the high speed radiator fans at any time, while maintaining the automatic operation of the fans. We do the same for the engine compartment fan.

    Radiator Fans

    Connect a wire to the ground (Pin #85) of the 2 high speed fan relays located on the relay carrier located in the driver’s side foot well. The relays are #20 and #22. Feed this wire to where your switch will be located. Connect the wire to one side of the switch. Connect another wire from the other contact on the switch and then connect the other end of this wire to a chassis ground point.

    With key on, this switch will now immediately turn on both radiator fans providing maximum cooling. When you turn the key off, the fans will continue to run for about 5 seconds until the relay shuts down. Your fan operation remains normal when the switch is off.

    Engine Compartment Fan

    Connect a wire to the ground of the relay located in the relay carrier behind the passenger seat, driver’s side. Relay #8. . Feed this wire to where your switch will be located. I simply fed the wire along the driver’s side of the car and under the door sill. Connect the wire to one side of the switch. Connect another wire from the other contact on the switch and connect the other end of this wire to a chassis ground point.

    With key on, this switch will now immediately turn on the fan drawing air into the engine compartment. When you turn the key off, the fan will continue to run for about 5 seconds until the relay shuts down. Your fan operation remains normal when the switch is off. This mod helps keep the engine compartment much cooler when driving around town and is particularly beneficial to any engine that draws its intake air from inside the engine compartment, such as the EVO SC.

    If you are adventurous, you can automate the operation of these switches so they will switch off at a specific speed, or operate when vacuum is present only, etc. You can choose any style switch you want and even use Porsche switches. I simply used 2 toggle switches that I installed in the batwing,

    Jim

  8. Targeted coolant temp is 194F and on cool days at highway speeds, you can maintain this temperature close enough. Turning the AC on will increase temperatures, partially offset by fan operation. Around town, coolant temps can reach as high as 220F+. Sunny days add to temps. Based on your gauge, your temp is around 215F. You will see 180F only twice during a drive cycle. Once while you pass by it as the engine warms up and once when you pass by it after engine shut down.

  9. Bill,

    Thanks again for the excellent response I think i might be sold on the resistor solution combined with the AEM meter since all the other options seem to be much less cost effective for possibly little advantage. Do you know if anyone has a write up on it ? Again thank you for your help.

    What part exactly were you looking for a write up on? If it's AEM meter ?'s or AFC Select MAF controller ?'s

    then I can share my experience... If it has to do with resistors, rheostats, or variable pots... then

    members Todd or porsche 1999 are the goto guru's...

    I wanted to give a quick update on my current setup as of last night ...

    After 7 months of running a "calibrated" maf signal

    I finally decided to track down the proper MAF housing size and got my hands

    on Todd's recommended "Cayman/Boxster 987" Maf housing . Brand new from

    Sunset Porsche parts the discount is still a lot ... $275 because it includes

    the actuall sensor which I can not use.

    All I wanted was the housing tube to plug my boxster/996 sensor into. I finally tracked

    down the proper size maf housing from a dismantler and saved myself

    over $200...It also has the screen built into it to help with air turbulence.

    In the process I also discovered a proper sized nice alternative

    Bosch maf housing for a lot less $$ then Porsche... (pm me if interested)

    My original 986 boxster maf housing measures inner diameter of 70-72mm.

    (76mm or 3 inch outer diameter)

    The 3.4 liter 996/Cayman maf housing measures inner diameter of 83-85 mm

    (90mm outer or 3.5 inch outer diameter)

    A difference of close to 20 percent in size.

    With my "calibrated" maf signal my air fuel ratios were staying a solid 12-12.5 and the car was running very strong.

    Even so I still felt that "tricking" the ECU with a calibrated signal or resistor may not be taking full advantage

    of all the fuel maps and how they were designed to work with proper air flow measurement from Porsche.

    Even though I really enjoyed my setup there was always a question in my mind if I

    was really allowing the programming to work correctly under those "calibrated" conditions.

    Since I want my 3.4 Boxster to run it's strongest at all times I decided it was time to

    switch over to the proper maf housing size.

    After modifying intake tube lengths for the new housing I got

    it to fit nicely.

    My current intake setup is:

    -Cone filter plugs onto front end of Cayman Maf Housing..

    -back end of housing plugs onto 3 inch intake tubing all the way to Throttle body.

    (996 throttle body is only 3 inches in diameter)

    I unpluggled the battery, reset my computer, and disabled

    my "AFC-select" maf voltage controller.

    After a few runs through the rpm range for the computer to learn the new setup

    everything seems to be working very nice.

    I have to say.... I think overall the engine feels stronger and more refined now.

    My peace of mind feels much better as well since I know for sure that the

    proper air measurement is working with the fuel maps as designed from Porsche,

    rather than a "calibrated" signal to trick the computer.

    Afr readings at wide open throttle are around 13 from low to mid rpms and then drops

    to around 12.5 for the upper rpm range.

    My initial impressions are that the car feels more responsive. Hard

    to say for sure because it was running quite fast before as well. Just seems to be more

    sorted out all around with partial throttle response being a bit more aggressive and

    then full throttle applications feeling a bit stronger up top.

    Since I have tried both methods I think overall, this is the way to go.

    Especially for peace of mind and knowing that you are taking full advantage of the

    way the 996 3.4 liter ecu was programed originally with the larger maf housing.

    I Think I will keep it like this for awhile ;^)

    As I mentioned in your other post:

    The reason for your difference in A/f at WOT is because your calibrated signal was different than it is now. Running at WOT at a 13:1 air fuel ratio will make your car feel like it has more pep since you are running lean.......maybe too lean. Especially running 91 octane fuel. Had you calibrated the signal with a higher ohm restistor, you would have had the exact same results. All you did was make your engine run leaner than it was. Now you simply "tricked" your engine into thinking it was getting less air than it really is by using a mechanical device rather than an electronic one.

  10. Right around 340 ohm works well for a stock 996 program using a stock boxster maf housing. I would put in a variable pot resistor, this will allow you to 'tune' the fuel trims right where you want them. 1999 explained this to me a few years ago when I did my first 3.4 conversion. I still think the best solution is to use a properly sized intake tract, as I'm not convinced that the small boxster intake system can flow enough air to feed the 3.4. Look how porsche increase the airbox size when they put the 3.4 into the 987 vs the 986.

    -Todd

    I wanted to give a quick update on my current setup as of last night ...

    After 7 months of running a "calibrated" maf signal

    I finally decided to track down the proper MAF housing size and got my hands

    on Todd's recommended "Cayman/Boxster 987" Maf housing . Brand new from

    Sunset Porsche parts the discount is still a lot ... $275 because it includes

    the actuall sensor which I can not use.

    All I wanted was the housing tube to plug my boxster/996 sensor into. I finally tracked

    down the proper size maf housing from a dismantler and saved myself

    over $200...It also has the screen built into it to help with air turbulence.

    In the process I also discovered a proper sized nice alternative

    Bosch maf housing for a lot less $$ then Porsche... (pm me if interested)

    My original 986 boxster maf housing measures inner diameter of 70-72mm.

    (76mm or 3 inch outer diameter)

    The 3.4 liter 996/Cayman maf housing measures inner diameter of 83-85 mm

    (90mm outer or 3.5 inch outer diameter)

    A difference of close to 20 percent in size.

    With my "calibrated" maf signal my air fuel ratios were staying a solid 12-12.5 and the car was running very strong.

    Even so I still felt that "tricking" the ECU with a calibrated signal or resistor may not be taking full advantage

    of all the fuel maps and how they were designed to work with proper air flow measurement from Porsche.

    Even though I really enjoyed my setup there was always a question in my mind if I

    was really allowing the programming to work correctly under those "calibrated" conditions.

    Since I want my 3.4 Boxster to run it's strongest at all times I decided it was time to

    switch over to the proper maf housing size.

    After modifying intake tube lengths for the new housing I got

    it to fit nicely.

    My current intake setup is:

    -Cone filter plugs onto front end of Cayman Maf Housing..

    -back end of housing plugs onto 3 inch intake tubing all the way to Throttle body.

    (996 throttle body is only 3 inches in diameter)

    I unpluggled the battery, reset my computer, and disabled

    my "AFC-select" maf voltage controller.

    After a few runs through the rpm range for the computer to learn the new setup

    everything seems to be working very nice.

    I have to say.... I think overall the engine feels stronger and more refined now.

    My peace of mind feels much better as well since I know for sure that the

    proper air measurement is working with the fuel maps as designed from Porsche,

    rather than a "calibrated" signal to trick the computer.

    Afr readings at wide open throttle are around 13 from low to mid rpms and then drops

    to around 12.5 for the upper rpm range.

    My initial impressions are that the car feels more responsive. Hard

    to say for sure because it was running quite fast before as well. Just seems to be more

    sorted out all around with partial throttle response being a bit more aggressive and

    then full throttle applications feeling a bit stronger up top.

    Since I have tried both methods I think overall, this is the way to go.

    Especially for peace of mind and knowing that you are taking full advantage of the

    way the 996 3.4 liter ecu was programed originally with the larger maf housing.

    I Think I will keep it like this for awhile ;^)

    The reason for your difference in A/f at WOT is because your calibrated signal was different than it is now. Running at WOT at a 13:1 air fuel ratio will make your car feel like it has more pep since you are running lean.......maybe too lean. Especially running 91 octane fuel. Had you calibrated the signal with a higher ohm restistor, you would have had the exact same results.

  11. Update:

    Took the time in the morning to change to the old belt (Porsche OEM part).

    It was quite cold outside and the issue seemed to be washed away.

    But the hoter the engine got and the higher the outside-temperatures raised, the more often the Voltage lowered and i hat my personal light-show of flashing lights at certain RPM´s.

    I am personally at the end of my ideas, tried to turn the alternator without belt, runs very smooth and easy without noise.

    Don´t know what else to check.

    Any ideas before i´m going to give it to the PZ ?

    Regards

    André

    Might be a bad regulator which can easily be replaced.

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