83 245T - Rough running and craps when cold?

Get a Bentley manual, It will really help you get your head around the K jet fuel injection system. My '82 used to run like crap when cold (but no black smoke) and would magically run great after 20 minutes as well. Turned out that theres a little vacuum daly valve inline with the control pressure regulator that had s*it the bed. I'd guess that there's something wrong in the control pressure regulator system...bad sensor, bad vacuum delay valve, cracked vacuum line etc. The key here is that there appears to be a coolant temp sensor that opens or closes after about 20 minutes and changes the routing of the vacuum through the CPR. Check that vacuum valve, your symptom sounds remarakbly like mine!

BobW

It sounds like that delay valve is the problem. About the size of a half dollar located just behind the distributor? Did you remove the dist. to replace it?

I think that's it. I found a white valve in the vacuum/pressure line just behind the distributor. Do you know if it would be available somewhere other than the dealer? Is it expensive?

Make sure the vacuum lines that the valve is in are going to the control pressure regulator, not the distributor. As I remember the delay valve you're after is blue and black.

Also, if you suspect the injector seals are bad, why not just replace them first?

It's disc shaped and the size you describe. I believe it is black on one side, red on the other but it's been a while since I've seen mine. It's not hooked to the distributor, Like Mike said, it's in a loop of vacuum lines going to the control pressure regulator. It's on the drivers side, towards the front of the block and under the intake manifold. I got mine in and out without removing anything but it was very difficult to get the clamps off and back on, space is very tight in there.

Probably easiest to source one at the dealer. I found a good one at a wrecking yard. See Bentley manual for proper procedure for testing. Mine would not pass vacuum in either direction, causing my symptoms.

Good luck

Bob W

I have the green/white Volvo service manuals for my car. It shows the position of that delay valve. I might remove the distributor to make the repair a little easier. It's very tight in there.