hi I have a 76 245 dl that doesn't idle well at all when cold (sitting over night) so far its had
new injectors
new aux air valve
cold start injector and thermo time switch checked and all ok
new warm up regulator
new vac lines
I'm hoping there must be something simple i haven't done yet aside from this the car runs great and starts very easily its just the rough and sometimes stalling when its cold, the aux air valve has been adjusted to open as far it can when cold. any help will be hugely appreciated!

try tweeking the base richness adjustment on the fuel distributor

Also known as the C/O adjustment.

I suggest this because you've changed all the injectors. Also it's easy.

CB wrote---"try tweeking the base richness adjustment on the fuel distributor" If the motor is running properly when warm than this is NOT the way to go. I've yet to see an auxiliary air valve opened all the way when cold--is that the way yours has been set? If so, it may be causing the warm up mixture to be too lean. -- Dave

fwiw
it's not possible to set the Aux Air Valve all the way open. there are limits to how far when you use that adjustment nut on the valve.

taking an 8MM long allen wrench and turning the CO adjuster 1/4 or less to the right...seeing what change if any...Then 1/4 turn to the left ...any change...just put it back to where it was.

a lot easier to rule it out. You'll know in 5 mins.

easier than going to the P and P to try and find another CPR or buying/getting a pressure tester and doing that test.



To OP: you did get new Injector Seals when you replaced the injectors. And new S-Hoses for the Aux Air Valve.

I understand it may be possible to improve the cold running by making a small adjustment to the mixture screw but the OP says it runs well when warmed up so playing with the mixture screw will not likely "cure" the actual problem. The answer lies elsewhere. There could be lots of maybe's when it comes to K-jet and that's why it's generally a better and more direct way of diagnosing a problem by hooking up a proper pressure gauge. Maybe the control pressure is too lean at warm-up -- or too rich -- or maybe the hot running pressure is off --- or -- maybe the auxiliary air valve is open to much when cold, etc. If the OP doesn't have diagnostic equipment it would be more productive to work with the components that directly affect the problem area. It's easy to get sidetracked with K-jet -- been there. -- Dave

also my air valve isn't fully open i would say about a 1/4 at the most

manuals:

http://www.volvowiringdiagrams.com/?dir=volvo/K-Jetronic
You should find all the greenbook pdfs here to cover it.

including
Warm Up Reg Adjustment .pdf


BEST for Trouble Shooting...compiled by and for actual Volvo Mechanics
From the same website:
http://www.volvowiringdiagrams.com/?dir=volvo/Trouble%20Shooting%20Guides

Download the Volvo Problem Solver Advanded Edition
Section 24...Covers the CIS KJet

HOWEVER:

Try to adjust the C/O.
The GreenBook CI Fuel Injection Fault tacing .pdf States on p.1:

"If CI System parts are replaced, then idle speed and the CO level must be checked and readjusted as necessary"

hope this helps

Thanks for all the help cb! Have adjusted the co and it's now idling very smoothly will get to a mechanic just to check the fuel pressure and co to make sure everything's as it should be.

The auxiliary air valve operation is the same as opening the throttle. It just speeds up the idle a little when cold. It cannot affect mixture.

Since adjusting the co (actually the overall mixture) improved the cold idle you have verified the problem is mixture. However, the co adjustment changes the mixture for all running modes. So now it may be running too rich when warm and will not pass smog (worst case). The only component that can change the mixture just when cold is the CPR.

the auxiliary air valve was replaced because the original was faulty (stuck in the shut position)
have just been to the mechanic to check all is ok and it turns out the car must have been running lean to begin with, I only adjusted it a quarter turn but its done the trick and has passed all the tests. its taken a long time to get this car running the way it should but I'm finally happy with it.

glad it worked out for you.

I hate it when I'm right. :)

Wagon Drk Green ?

Cheers

i will close the aux air as much as it can be and see how it goes only reason i did that was the old one was constantly closed and it ran even worse on start up, all vac lines and aux air valve hoses have been replaced along with injector seals, I don't have a fuel pressure tester but i will do my best to track one down since I'm at a total loss as to what it could be, the car isn't blowing any smoke on start up ill have a play round in the garage today to see if theres anything i could have missed, are there any other k-jet components that could be causing the problem?

Is there any smoke, white or black, when cold?

It sounds like it is miss firing due to too lean a mixture when cold. You may need a k-jet pressure test gauge to diagnose it for sure. However, it's the warm up regulator (also known as control pressure regulator) which is suppose to enrich the mixture when cold. Was the new CPR actually new or rebuilt? You might try a used one from a PnP. These units are pretty durable.

"the aux air valve has been adjusted to open as far it can when cold."

Is that the way to go? Would think that it would prefer to be richer for cold idle than leaner.