Just landed from Heathrow carrying a complete Csi system. I
Question and help needed
- Thread starter Farzad Arjmand
- Start date
I defer to the experts, and hopefully you can get your car to sfdon soon.
In the meantime, there are only a couple of inputs to a D-Jet system:
Make sure your vacuum line and electrical connector to the MAP sensor are in place. (see attached pdf)
There are only three other inputs for the D-Jet: Air temp and water temp sensors affect the operation, the throttle valve switch affects injector timing(?).
I once had the experience on my '72 MBZ V-8 with D-Jet that the air temp sensor on the air intake was not seated properly after a filter check. Man, my engine went wild, just a you describe: black smoke, barely running, misfiring, etc. I re-traced my steps, found the badly seated connector, and that was it, purring like a kitten.
On the #9, I believe the air temp sensor is the sensor to the right of the throttle body. The throttle valve switch is to the left.
The water temp sensor is under the fuel pressure regulator on the intake side. This affects the cold start circuit:
The knob on the ECU unit controls the fine-tune for the CO level after you set the idle with the idle screw on the throttle body. Someone with an exhaust tester can help you get that dialed back in. An expert could probably dial the knob in by measuring the resistance across the potentiometer (the knob's function), but I don't know what a nominal value should be.
Hopefully just a dislodged connector, and not the end of the world! Good luck!
In the meantime, there are only a couple of inputs to a D-Jet system:
Make sure your vacuum line and electrical connector to the MAP sensor are in place. (see attached pdf)
There are only three other inputs for the D-Jet: Air temp and water temp sensors affect the operation, the throttle valve switch affects injector timing(?).
I once had the experience on my '72 MBZ V-8 with D-Jet that the air temp sensor on the air intake was not seated properly after a filter check. Man, my engine went wild, just a you describe: black smoke, barely running, misfiring, etc. I re-traced my steps, found the badly seated connector, and that was it, purring like a kitten.
On the #9, I believe the air temp sensor is the sensor to the right of the throttle body. The throttle valve switch is to the left.
The water temp sensor is under the fuel pressure regulator on the intake side. This affects the cold start circuit:
The knob on the ECU unit controls the fine-tune for the CO level after you set the idle with the idle screw on the throttle body. Someone with an exhaust tester can help you get that dialed back in. An expert could probably dial the knob in by measuring the resistance across the potentiometer (the knob's function), but I don't know what a nominal value should be.
Hopefully just a dislodged connector, and not the end of the world! Good luck!
Attachments
Check voltage at coil with key on
disconnect cold start injector
what voltage?
im in SF for 5 days then gone skiing next week.
disconnect cold start injector
what voltage?
im in SF for 5 days then gone skiing next week.
Farzad Arjmand
Active Member
thank you for your detail input , Sunday I will do , and let you know if I find the solution
Farzad Arjmand
Active Member
so I disconnected radio wires , (wiring had no issues) and let the car warm up and after all the smoke cleared , I adjusted ECU knob little by little , now the rpm surges between 200 and 1000 rpm while warmed up in idling, I did not drive the car ....any suggestions?? is it vacuum line? what could it be?
I have had once rpm jumping up and down in BMW with BOSCH Motronic ... after I have checked almost all including vacuum, fuel pump, charcoal, MAF I noticed there is one more part in the injection system ... fuel pressure regulator.
It's dry side is driven by small pipe with vacuum from intake manifold. Once I slipped the vacuum pipe I notice gas/fuel coming from the regulator.
Green and Eco fuel with ethanol made the diaphragm brittle. It cracked and caused small fuel delivery to vacuum system thus intake. ECU was trying to stabilize the rpms but was not able to.
It looks like CSi has nut operated regulator
If the pressure is incorrect the whole system will not work properly but to be honest it is probably someting different.
Adjustments
Pressure regulator Remove hose at pressure regulator and connect pressure gauge to regulator. Operate fuel pump. Pressure should be 28 psi (2.0 kg/cm2 ). Loosen lock nut on regulator and adjust as necessary. Replace regulator if specifications can not be achieved.
Source (also some more about idling):
It's dry side is driven by small pipe with vacuum from intake manifold. Once I slipped the vacuum pipe I notice gas/fuel coming from the regulator.
Green and Eco fuel with ethanol made the diaphragm brittle. It cracked and caused small fuel delivery to vacuum system thus intake. ECU was trying to stabilize the rpms but was not able to.
It looks like CSi has nut operated regulator
If the pressure is incorrect the whole system will not work properly but to be honest it is probably someting different.
Adjustments
Pressure regulator Remove hose at pressure regulator and connect pressure gauge to regulator. Operate fuel pump. Pressure should be 28 psi (2.0 kg/cm2 ). Loosen lock nut on regulator and adjust as necessary. Replace regulator if specifications can not be achieved.
Source (also some more about idling):
The regulator is mechanical. It's not vacuum operated. The line you likely removed was the return line back to the tank
Farzad Arjmand
Active Member
Thank you , I am checking to see if this is the problem ,,,, you are a big help , Thank you for your time
Farzad Arjmand
Active Member
Excuse me - I spoke with you.
On the phone.
Never tell mistruths on this site.
It will bite you.
I quoted my shop rate to you and you declined to bring your car in.
On the phone.
Never tell mistruths on this site.
It will bite you.
I quoted my shop rate to you and you declined to bring your car in.
Stop telling porkies boys …
I hate liars …
kiss and make up and move on !!!
I hate liars …
kiss and make up and move on !!!
Nobody puts SF Don in the corner 
Farzad Arjmand
Active Member
I called you and spoke to you, you said you are going away for a week and will call me up on return, its all good... I did wait for two weeks and no answer ... your rate has nothing to do with it .... respect