So my 81 245 N/A has a no start issue. Hooked up my pressure tester, and with car off and just the pump jumpereed and running (being as the car wouldn't run anyways), and got readings of 70 system pressure and 30 rest pressure, all good there. Control pressure reading is where it went bad, started at 55psi and went up from there.

So I took off the CPR, took it apart and cleaned it up as best I could. Nothing noticably wrong, in fact it looks pretty darn nice inside, save for the O ring I there, while not torn, looked thin and old so I replaced it with one out of my O ring kit. Hooked the CPR back up and the System and Rest pressures were identical, but when I take the Control reading I get about 1psi....if that. Now keep in mind this was also with just the pump running, not with the car running.

Is that normal to have such a low reading until the CPR gets power? Or did I reassemble it incorrectly? Was the new O ring maybe too thick? Should I just put it back together and see if it runs? Learning is fun!

Thanks in advance

Shaun

I sure wish Lucid was on the board right now!

He is the man who knows the K Jet system.

What was the reason for tearing into the CPR? Was because of the engine running to lean?

If it was thought to be excessive control pressure of a 50 to 55 psi reading, that should have been normal.
I know this only because I looked it up in my green books for a '78.

I don't know how you have the CPR hooked up but it only controls the pressure to the top of the fuel distributor to control the metering slots or the rate of rise or height of the air flap. There is a heater and lever that simulates the engine temperature when warming up.

According to my quick glance of the book, the return fuel from the CPR sits in behind the same
Line pressure setup so either one of the pressure check valves dumps fuel back to the tank.


Line pressure is normally at 64 to 75psi towards those slots. I notice that "Each" injector has its on regulator inside the fuel distributor. The frequency valve influences the pressure on the underside of those regulating valves for fine mixture control in conjunction with the O2 sensor.
Is that valve buzzing while the engine runs?

All these pressures are controlled by shims under springs all though fuel distributor. Mostly at enter and exit points.
The rest pressure is 24 psi after shut down and during a 20 minute period it should hold 14psi. This is know as pressure drop.

Now these numbers above were noted as being with the CPR all warmed up?

Now with all this information, that I had to look up, leaves me really guessing at the new "low pressure reading" from the CPR or is it the way you have it setup for test.

My thinking is that without the fuel distributors pressure regulation circuits and its return flow rate back to the tank, the CPR can not check by itself. It has to have those perimeters in play!

All these things are fairly simple in themselves. But now throw in some plugged up inlet screen(s), well, you got to deal with those issues first. Don't tear any deeper!

This system is straight forward. Keep the fuel system clean there will be virtually no problems for many years!

Try to find FAQ's or look under "Lucids" profile for past posts. Better yet, post a "shout out."
Someone knows how to tap him on the shoulder!

I think he has helped me a lot on these systems!

Phil

I'm not familiar with your previous work so this may be a dumb question but, have you checked anything else?

Yup, went down the checklist of things to check, only thing wonky was the CPR readings.

Check valve is for fuel pump is not working.

http://www.k-jet.org/

http://www.volvowiringdiagrams.com/?dir=volvo/240%20Wiring%20Diagrams
(TP30363-2 CIS System Repairs.pdf)


Hope that helps.