[SeaDweller]

Not to be picky, but I believe everyone is referring to the Auxiliary Air Regulator, not the Auxiliary Air Valve. Also, the thermo time switch controls the cold start injector, not the WUR.

Your symptoms could be caused by many things. The WUR, Thermo Time Switch, Cold Start Injector, AAR, Thermo Valve, improper routing of vacuum lines, system/control pressure, etc. I've found that narrowing down your options by eliminating what's working is the best approach.

If the engine fires immediately, then you can pretty much eliminate the thermo time switch and cold start valve. If the engine runs well when warm, it usually points to the WUR or the AAR. Superman's suggestion to check the operation of the AAR is a good one, however you don't have to remove both hoses. The outer hose is easy to access and remove. As suggested, use a mirror, but shine the light into the mirror itself (reflecting the light) and it'll illuminate the interior of the AAR. An initial check would be to see if the AAR is open. You may find that it's only open enough that the opening looks like a quarter moon, but that's ok.

Another thing to check is the vacuum hose routing to make sure it's correct. I've found that a "quick fix" by some sly mechanics is to re-route vacuum lines and crank up the mixuture so the WUR is taken out of the system for the most part. This is easier than properly troubleshooting the engine.

Finally, check the system and control pressures to make sure they're within spec. The WUR could be slighly out of adjustment and providing too much, or not enough enrichment during the cold start process. If that's the case, then the mixture itself is probably out of adjustment as well.

Does the engine pulse when it's warmed up?

In some cases, there are multiple issues, but I think that's pretty rare. What makes things difficult with CIS is many components can mimick the same symptom, so going through and troubleshooting the entire system is usually necessary.