CIS Fuel Injected 928s - My Top 10 Personal Reflections
03-27-2014, 01:33 AM
#1
Rennlist Member
Thread Starter
CIS Fuel Injected 928s - My Top 10 Personal Reflections
Unbelievably, I have 12 years of 928 ownership under my belt already. It sure has gone by fast. As I reflect on what I know now and wish I knew back then would be how all those crazy CIS components work together to keep that 928 running like a top. I have come to appreciate that the Bosch CIS K-Jet system is beautifully simple but strangely complex.
Yes, you can buy Ben Watson's book or the Bosch's Big Blue, but sometimes you need someone just to tell you some key pointers right up front, in one post have you to forgo endless searches on rennlist for CIS, WUR, Cold start or hot start issues; where's the fun in that! Now by no means am I expert like Dennis or Scott (RIP) but I would say I've learned a couple of pointers. Here's some quick memoirs that I wanted to share for all those who love not having an ECU.
1. BUY CIS GAUGES , BUY CIS GAUGES , BUY CIS GAUGES - You have as much chance of truly troubleshooting or tuning your system as casting magic spells without
2. BUY the super long 3m A/F tool - It just makes your life easier
3. BUY & Install a digital A/F gauge that comes with an 02 Sensor - This will truly dial your CIS system in to that favorite 14.7:1 ratio
4. The Control Pressure Regulator aka WUR is the CIS version of an ECU - If this little mechanical heater and spring black box isn't working, everything else gets mad too. First thing you check with your fresh new CIS gauges
5. Do NOT randomly turn the A/F mixture left for leaner or right for richer - Even the smallest adjustment can increase or decrease your A/F ratio by 1 or more.
6. Do NOT randomly turn your idle screw hoping that will automagically fix all your problems - We are the opposite of Nike. Just Don't!
7. If you find your car hard starting COLD as in RAH-RAH-RAH-RAH-RAH-RAH and nothing happens. Check that damn thermo-time sensor. Most likely out of range in the OHM department.
8. If you find your car starting and then instantly dying when cold, check those pesky fuel check and system pressure release valves.
9. If you find your car starts great but after going to the supermarket, you start your ride and it decides not to turn over, it's probably due to that crazy fuel accumulator and the diaphragm is most likely leaking causing a WARM start problem.
10. When tuning your CIS system, have the CIS gauges installed, record and document the COLD, WARM and SYSTEM pressure readings. Give yourself a baseline for future reference. Once your fuel system readings are in spec and you have the items mentioned above, feel free to run crazy with that A/F mixture screw now until you have everything dialed in! NOW GO FOR A RIDE!
Feel free to share some your favorite CIS experiences!
Yes, you can buy Ben Watson's book or the Bosch's Big Blue, but sometimes you need someone just to tell you some key pointers right up front, in one post have you to forgo endless searches on rennlist for CIS, WUR, Cold start or hot start issues; where's the fun in that! Now by no means am I expert like Dennis or Scott (RIP) but I would say I've learned a couple of pointers. Here's some quick memoirs that I wanted to share for all those who love not having an ECU.
1. BUY CIS GAUGES , BUY CIS GAUGES , BUY CIS GAUGES - You have as much chance of truly troubleshooting or tuning your system as casting magic spells without
2. BUY the super long 3m A/F tool - It just makes your life easier
3. BUY & Install a digital A/F gauge that comes with an 02 Sensor - This will truly dial your CIS system in to that favorite 14.7:1 ratio
4. The Control Pressure Regulator aka WUR is the CIS version of an ECU - If this little mechanical heater and spring black box isn't working, everything else gets mad too. First thing you check with your fresh new CIS gauges
5. Do NOT randomly turn the A/F mixture left for leaner or right for richer - Even the smallest adjustment can increase or decrease your A/F ratio by 1 or more.
6. Do NOT randomly turn your idle screw hoping that will automagically fix all your problems - We are the opposite of Nike. Just Don't!
7. If you find your car hard starting COLD as in RAH-RAH-RAH-RAH-RAH-RAH and nothing happens. Check that damn thermo-time sensor. Most likely out of range in the OHM department.
8. If you find your car starting and then instantly dying when cold, check those pesky fuel check and system pressure release valves.
9. If you find your car starts great but after going to the supermarket, you start your ride and it decides not to turn over, it's probably due to that crazy fuel accumulator and the diaphragm is most likely leaking causing a WARM start problem.
10. When tuning your CIS system, have the CIS gauges installed, record and document the COLD, WARM and SYSTEM pressure readings. Give yourself a baseline for future reference. Once your fuel system readings are in spec and you have the items mentioned above, feel free to run crazy with that A/F mixture screw now until you have everything dialed in! NOW GO FOR A RIDE!
Feel free to share some your favorite CIS experiences!
03-27-2014, 02:39 AM
#2
Team Owner
nice post, thanks.
I am sure your wisdom will come in handy
I am sure your wisdom will come in handy
03-27-2014, 08:34 AM
#3
Rennlist Member
subscribed! thanks for the post.
03-27-2014, 11:20 AM
#7
Great post and information.
Trending Topics
03-27-2014, 05:49 PM
#10
Rennlist Member
Correct in every aspect, and worthy of being Stickied! My ownership is now about the same length, and its been running like a top since around year 2, and a real joy in every way.
jp 83 Euro S AT 55k
jp 83 Euro S AT 55k
03-27-2014, 06:02 PM
#11
Race Car
Nicely done
Jay? Jay Kem**? Oh, wait that was the email list.
Nice points, definitely the usual suspects. So that's for fuel, now you should muster up a companion piece for electrical ie ignition.
Without putting earnest thought into it, probably goes something like:
Grounds, grounds, grounds;
What's so special about that green wire;
Broken Bosch clips, broken Bosch clips,
Tarnation, look at those old fangled fuses,
Try reversing the fuel pump polarity momentarily to clear obstruction,
MBS: that's your HVAC resistor pack, not the mother ship,
Whaddyamean the ignition is triggered by a 6V signal???? (is it 6? I'm foggy on that one)
The EZK really can go bad...occasionally,
Nice points, definitely the usual suspects. So that's for fuel, now you should muster up a companion piece for electrical ie ignition.
Without putting earnest thought into it, probably goes something like:
Grounds, grounds, grounds;
What's so special about that green wire;
Broken Bosch clips, broken Bosch clips,
Tarnation, look at those old fangled fuses,
Try reversing the fuel pump polarity momentarily to clear obstruction,
MBS: that's your HVAC resistor pack, not the mother ship,
Whaddyamean the ignition is triggered by a 6V signal???? (is it 6? I'm foggy on that one)
The EZK really can go bad...occasionally,
03-29-2014, 08:05 AM
#14
Rennlist Member
Unbelievably, I have 12 years of 928 ownership under my belt already. It sure has gone by fast. As I reflect on what I know now and wish I knew back then would be how all those crazy CIS components work together to keep that 928 running like a top. I have come to appreciate that the Bosch CIS K-Jet system is beautifully simple but strangely complex.
Yes, you can buy Ben Watson's book or the Bosch's Big Blue, but sometimes you need someone just to tell you some key pointers right up front, in one post have you to forgo endless searches on rennlist for CIS, WUR, Cold start or hot start issues; where's the fun in that! Now by no means am I expert like Dennis or Scott (RIP) but I would say I've learned a couple of pointers. Here's some quick memoirs that I wanted to share for all those who love not having an ECU.
1. BUY CIS GAUGES , BUY CIS GAUGES , BUY CIS GAUGES - You have as much chance of truly troubleshooting or tuning your system as casting magic spells without
2. BUY the super long 3m A/F tool - It just makes your life easier
3. BUY & Install a digital A/F gauge that comes with an 02 Sensor - This will truly dial your CIS system in to that favorite 14.7:1 ratio
4. The Control Pressure Regulator aka WUR is the CIS version of an ECU - If this little mechanical heater and spring black box isn't working, everything else gets mad too. First thing you check with your fresh new CIS gauges
5. Do NOT randomly turn the A/F mixture left for leaner or right for richer - Even the smallest adjustment can increase or decrease your A/F ratio by 1 or more.
6. Do NOT randomly turn your idle screw hoping that will automagically fix all your problems - We are the opposite of Nike. Just Don't!
7. If you find your car hard starting COLD as in RAH-RAH-RAH-RAH-RAH-RAH and nothing happens. Check that damn thermo-time sensor. Most likely out of range in the OHM department.
8. If you find your car starting and then instantly dying when cold, check those pesky fuel check and system pressure release valves.
9. If you find your car starts great but after going to the supermarket, you start your ride and it decides not to turn over, it's probably due to that crazy fuel accumulator and the diaphragm is most likely leaking causing a WARM start problem.
10. When tuning your CIS system, have the CIS gauges installed, record and document the COLD, WARM and SYSTEM pressure readings. Give yourself a baseline for future reference. Once your fuel system readings are in spec and you have the items mentioned above, feel free to run crazy with that A/F mixture screw now until you have everything dialed in! NOW GO FOR A RIDE!
Feel free to share some your favorite CIS experiences!
Yes, you can buy Ben Watson's book or the Bosch's Big Blue, but sometimes you need someone just to tell you some key pointers right up front, in one post have you to forgo endless searches on rennlist for CIS, WUR, Cold start or hot start issues; where's the fun in that! Now by no means am I expert like Dennis or Scott (RIP) but I would say I've learned a couple of pointers. Here's some quick memoirs that I wanted to share for all those who love not having an ECU.
1. BUY CIS GAUGES , BUY CIS GAUGES , BUY CIS GAUGES - You have as much chance of truly troubleshooting or tuning your system as casting magic spells without
2. BUY the super long 3m A/F tool - It just makes your life easier
3. BUY & Install a digital A/F gauge that comes with an 02 Sensor - This will truly dial your CIS system in to that favorite 14.7:1 ratio
4. The Control Pressure Regulator aka WUR is the CIS version of an ECU - If this little mechanical heater and spring black box isn't working, everything else gets mad too. First thing you check with your fresh new CIS gauges
5. Do NOT randomly turn the A/F mixture left for leaner or right for richer - Even the smallest adjustment can increase or decrease your A/F ratio by 1 or more.
6. Do NOT randomly turn your idle screw hoping that will automagically fix all your problems - We are the opposite of Nike. Just Don't!
7. If you find your car hard starting COLD as in RAH-RAH-RAH-RAH-RAH-RAH and nothing happens. Check that damn thermo-time sensor. Most likely out of range in the OHM department.
8. If you find your car starting and then instantly dying when cold, check those pesky fuel check and system pressure release valves.
9. If you find your car starts great but after going to the supermarket, you start your ride and it decides not to turn over, it's probably due to that crazy fuel accumulator and the diaphragm is most likely leaking causing a WARM start problem.
10. When tuning your CIS system, have the CIS gauges installed, record and document the COLD, WARM and SYSTEM pressure readings. Give yourself a baseline for future reference. Once your fuel system readings are in spec and you have the items mentioned above, feel free to run crazy with that A/F mixture screw now until you have everything dialed in! NOW GO FOR A RIDE!
Feel free to share some your favorite CIS experiences!
03-29-2014, 11:58 AM
#15
Nordschleife Master
I think its the 3mm hex, usually people get the Stahlwille with a universal joint.
Stahlwille
10508
*
Stahlwille special tool to adjust the CO mixture on the Porsche 928 with 4 valves. Flexi-joint with 3mm hex bit. 360mm long. No longer listed by Stahlwille. These are now SOLD OUT and are No Longer Available!
$49.95
SOLD
OUT
Stahlwille
10507NKK-3
*
CO adjustment tool, with 3mm ball end hex tip, for K-Jetronic fuel injection. Ball ended hexagon drivers DRALL, for use on hexagon socket head screws, swivel angle up to 25º each side. Chrome Alloy Steel, chrome plated, black tips. With 2 component handle. Overall length 400mm.
Make payments with PayPal - it's fast, free and secure!
$25.58
Stahlwille
10508
*
Stahlwille special tool to adjust the CO mixture on the Porsche 928 with 4 valves. Flexi-joint with 3mm hex bit. 360mm long. No longer listed by Stahlwille. These are now SOLD OUT and are No Longer Available!
$49.95
SOLD
OUT
Stahlwille
10507NKK-3
*
CO adjustment tool, with 3mm ball end hex tip, for K-Jetronic fuel injection. Ball ended hexagon drivers DRALL, for use on hexagon socket head screws, swivel angle up to 25º each side. Chrome Alloy Steel, chrome plated, black tips. With 2 component handle. Overall length 400mm.
Make payments with PayPal - it's fast, free and secure!
$25.58