Hello Everybody

I finally have removed the Control Pressure Regulator from my California 240 B21F 1981. I have taken the unit apart, plenty of cleaning to do. I understand the basic workings of this device (I have the Bentley Bosch FI & Engine Mgmnt and the Bosch K-Jet system books).

My question lies in the vacuum connections. The Bentley book shows the CPR with one vacuum port at the base of the unit. Mine has two, as well as a port cast as part of the top cover. The earlier versions of the CPR use this top port for manifold vacuum. I assume on mine, it is for atmosphere. The two on the base I'm guessing go in a loop to the wax thermal thing screwed into the head. I'm not sure my vacuum lines are routed correctly. Any help out there?

Thanks

Scott in Auburn

I don't know if this will help you or not, but here's how my 81 California K-Jet is set up:

Vacuum Hose Routing for 1981 240. Applies to both air control valve version and auxiliary air valve version.


Front top manifold to fender-side of thermostat valve below forward bolt for #2 intake.

Engine side of thermostat valve about 2 inches to T in vacuum line. Straight out the T a couple of inches to light-colored side of delay valve. (Delay valve is two tone, cylindrical, maybe 1 inch in diameter, plastic, about the size of a ping pong ball.) Dark end of delay valve to lower vacuum nipple on CPR. Upper vacuum nipple on CPR to third leg of T you installed.




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Thanks for all the help, 81 242 Brick Off Blocks, stock, B21F, M46; 86 244, 142k , auto.

Doug

Yes this helps a lot, thanks!

By the way, does your car exhibit a smooth idle?

Scott in Auburn, CA

No, my car does not exhibit a smooth idle. Compression is great, and the engine runs well at all other times and under all other conditions. I really would like to smooth out the idle. I've been wondering about the CPR as the culprit. Was it hard to remove and clean? What, if any, new parts are typically needed? I'd like to buy the parts ahead of time. Please let me know if the job you did makes much difference with your idle.
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Thanks for all the help, 81 242 Brick Off Blocks, stock, B21F, M46; 86 244, 142k , auto.

Hi Doug

CPR was not difficult to remove and clean, you must remove the intake manifold, and the CPR is attached to its mount via two socket cap screws. Undo the two fuel lines, and remove.

I can't say that cleaning it helped a great deal with my idle, but you must understand I am dealing with a project car here. So far I've had the cylinder head rebuilt, installed a new engine wiring harness, replaced the O2 sensor, replaced the main fuel pump, as well as the usual filters, rotor, cap wires and plugs.

I'm sure I've left something I've done out...

Anyway, when I got the car it shook horribly. Now it shakes less, not too bad actually. Cold it barely idles and warmed up it may be idling a bit too fast, I need to check with a tach again. So it sounds like a vacuum leak to me, but I can't find anymore than I've already fixed. I've swapped out the Idle Air Control motor, no difference. Maybe the CPU is shot.... Anyway I've most likely more than one issue going on at once. I need to purchase a fuel pressure tester to get anywhere with this K-Jet.

Thanks for your help

Take Care

Scott in Auburn, CA

Scott- the third port is just a vent. The two vacuum ports go to the blue plastic thermal vacuum switch and check valve on a B21FT but I am not quite sure what yours should look like. I can draw out the turbo lines if you want, but I am tired tonight. Let me know if you want that info.

Thanks,

The blue plastic fitting has an 'upper' and a 'lower' port, as does the base of the CPR. Can you recall which goes to which? I assume the Turbo and N/A would be the same.

Thanks

Scott