Need some help from the engine bay wire and vacuum experts...

[Damon88]

Hey guy, I was going through my engine bay cleaning up a couple things and noticed a plug on the left side of engine bay on the back that was taped up. Bentley says its the fuel injection harness connection. Assuming this should be plugged in somewhere..

Next is a Vacuum line that comes from there left side on engine bay near the rear strut mount and it goes across to the right Side of motor to a valve of some sort. it looks like it was cut or there was an adapter that held it together. Not sure why the PO has these unplugged. Any help would be great.. Thanks

[Flat6pac]

On the first picture, that plug isn’t used on a 78/79 3.0
It was used on the lambda harness from 80/83 which is separate from the engine harness.
Later used on the 6 injectors for Carrera
I’d have to study the rest of the pictures and they’re not clear.
Bruce

[Damon88]

did some more digging and found out that Vacuum line that is disconnected is coming from the Deceleration Air valve. No idea why the PO would have cut the line..

[Damon88]

Originally Posted by Flat6pac

On the first picture, that plug isn’t used on a 78/79 3.0
It was used on the lambda harness from 80/83 which is separate from the engine harness.
Later used on the 6 injectors for Carrera
I’d have to study the rest of the pictures and they’re not clear.
Bruce

Thanks Bruce,

This car has a replacement Engine. So it must have come out of a 80/83 car. Mystery solved. I did find the vacuum hose is coming from the Deceleration air valve...

Thanks for helping out bud!!

[Damon88]

or the hose is coming from the Auxiliary Air Valve .. Trying to get a better understanding and pic from the Bentley manual...

[boyt911sc]

Damon,

Could you check the last 2 characters on the intake runners part numbers? Are they -2R or -4R? The decel valve shown in your picture belong to later ‘80~’83 SC motors.

Tony

[Damon88]

Originally Posted by boyt911sc

Damon,

Could you check the last 2 characters on the intake runners part numbers? Are they -2R or -4R? The decel valve shown in your picture belong to later ‘80~’83 SC motors.

Tony

Hi Tony, I will check first thing tomorrow. My car is a 78 sc but has a replacement motor. Thanks to Bruce and yourself its at least a 80/83 motor that was installed. So im not sure if there are parts on this motor that don't need to be hooked up as the car is a 78.. Car is new to me as of December.. But hey I found some useful info already !! Cheers

[boyt911sc]

Damon,

Look for the serial number of the motor located at the lower right side of the alternator fan housing. Near that spot is the stamped engine type (930/xy). And if look at the Bosch ID # right behind the air filter cover (snorkel) is the fuel distributor (0-438-100-xyz). The last 3 digits will identify which FD you have on your motor.

Most likely, your motor is a US spec late SC (‘80~’83) that has lambda/OXS and a non-vacuum assisted WUR. Let’s first identify what CIS components you have on your motor. You can not mixed & match the critical CIS components like WUR, FD, ignition distributor, etc. Keep us posted.

Tony

[Damon88]

Originally Posted by boyt911sc

Damon,

Look for the serial number of the motor located at the lower right side of the alternator fan housing. Near that spot is the stamped engine type (930/xy). And if look at the Bosch ID # right behind the air filter cover (snorkel) is the fuel distributor (0-438-100-xyz). The last 3 digits will identify which FD you have on your motor.

Most likely, your motor is a US spec late SC (‘80~’83) that has lambda/OXS and a non-vacuum assisted WUR. Let’s first identify what CIS components you have on your motor. You can not mixed & match the critical CIS components like WUR, FD, ignition distributor, etc. Keep us posted.

Tony

Morning Tony , here is what I found. Thanks again for helping with this!!

Engine serial #6402219
Engine Type 930/07
FD. 077

[Damon88]

little more digging. I think my motor is a 1980 US motor.

[boyt911sc]

Originally Posted by Damon88

little more digging. I think my motor is a 1980 US motor.

Damon,

Yes. Your new replacement motor is a 1980 production (USA/CAN) that had lambda/OXS. You will need the 6-pin plug you found earlier in conjunction with an ECU and OXS to get this particular motor to run properly. Did you get the lambda box (ECU) and the wire harness? Are you able to start and run the motor?

You have to make a decision how you would like this motor to run. Run the motor with the lambda system or without like your previous motor. Could you verify if the WUR is 0-438-140-072? The WUR is mounted on intake runner #2 (driverside). Keep us posted.

Tony

[Damon88]

Tony,

Motor runs good and strong. No issues besides some cold start up issues but since have been resolved for now I hope haha

WUR

Stamp on side says 234

Top # 086
Another top # 680
And one more #487

Little history on car. Just purchased the car in December. Lots of service records showing motor and clutch replacement on 07. But nothing on where motor came from. Runs strong, but I was having cold start up issues with surging and having to give it gas to start. So yesterday I went through all vacuum lines and ended up finding a blue ish plug on the back of the intake not plugged in. Also this is when I found the vacuum line not attached to anything. Once back together the car started right up with no idle issues on cold start. I also notice the fuel pump make no noise now when ignition key is turned to accessory before Turing over. Sorry just trying to paint a picture on what was going on…

Out of all this I found out what motor I have and my car is running great haha but would love your input. Thanks again for all your help. I very much appreciate everyone on this forum and there knowledge. Cheers

[boyt911sc]

Good to hear it is running. You don’t need to touch the gas pedal to start a fuel injected motor like CIS. If you do, there something wrong with your fuel injection system. Without knowing your control and system fuel pressures, it is difficult to tell what is the culprit for your cold start problem.

The numbers you posted are the serial # and cast # of the WUR. Look on top of the WUR. All Bosch CIS warm up regulators have these numbers on top: 0 438 140 XYZ. The last 3 digits identify your specific WUR.

Tony

[Damon88]

Last 3 WUR# 140

Sorry for my long last reply. What I ‘meant to say is, after plugging in the plug on back of intake. The car starts up like it should. No issues now with cold start..

Thanks again

[boyt911sc]

Originally Posted by Damon88

Last 3 WUR# 140

Sorry for my long last reply. What I ‘meant to say is, after plugging in the plug on back of intake. The car starts up like it should. No issues now with cold start..

Thanks again

Damon,

The last 3 digits for the WUR are not “140”. Go back and clean the top surface. Next to “140” are the 3 digits (stamped or punched). They should be 072. Take a look at the picture below:



Tony

[Damon88]

Ahh ok yes

089

Thanks for your patience.

[boyt911sc]

Originally Posted by Damon88

Ahh ok yes

089

Thanks for your patience.

Damon,

If you are happy and satisfied how your motor is running, good for you. Your fuel distributor (-077) and your WUR-089 are mixed/missed match. Do you have a picture of your WUR? Thanks.

Tony

[Damon88]

Originally Posted by boyt911sc

Damon,

If you are happy and satisfied how your motor is running, good for you. Your fuel distributor (-077) and your WUR-089 are mixed/missed match. Do you have a picture of your WUR? Thanks.

Tony

Hi Tony,

Car seems to run fine... but I need to get the proper tools so see how efficiently the CIS is running. it smells rich while running. again just learning about these motors. I would rather not have it mix/matched if it means the car potentially will run its best. would love your thoughts on what is the best route to go from here. End of the day I want to car to run the best it can, at what ever cost... here is the best pictures I can get of the WUR without removing some parts. Cheer's

[boyt911sc]

Damon,

You need to identify the CIS components on your motor (1980 SC US/CAN). For example:
FD-077.............correct.
WUR-089..........should be -072/-090.
Intake runners...2R or -4R?.....should be -2R.
ECU/OXS...........installed or deleted? You need the ECU/OXS to control the FV.
Ignition distributor..........post a picture and Bosch ID #.

Tony

[Damon88]

Originally Posted by boyt911sc

Damon,

You need to identify the CIS components on your motor (1980 SC US/CAN). For example:
FD-077.............correct.
WUR-089..........should be -072/-090.
Intake runners...2R or -4R?.....should be -2R.
ECU/OXS...........installed or deleted? You need the ECU/OXS to control the FV.
Ignition distributor..........post a picture and Bosch ID #.

Tony

Intake runners 2R
Bosh distributor #0 237 304 016
There is no OXS Box under passenger seat and can’t located the ECU ..

Would changing the WUR to a 072 or a 090 help with running better /smoother ?

Cheers