Guys: I've played with alot of these ccc qjets and a few years back had a TPS that I couldn't keep adjusted. Spent some time with it and discovered that the spring beneath the TPS was allowing the entire unit to move in the bore as the plunger was pushed in. I found a stronger spring figuring someone before me had swapped in the wrong one. Well last week while messing with my 85 TA I found the same problem but I pulled the spring and verified it's the correct one per some used carbs in that box in the corner. Doubled up two springs (parallel not in series) and put it back together.

Anyway, anyone else seen this problem? I've really only checked these two carbs as I thought the first was a fluke. Are the springs just weak with age? Should a rebuild kit include a new spring? Does a new TPS include a replacement spring? (I can't remember, I usually pull a known good used one).

Wanted to throw this out there as I was curious.

 

I'm far from being a Guru, I haven't even opened my carb yet, but that's very interesting information to keep in mind when dealing with TPS problems. However, I would guess that the actual problem lies in that the TPS itself has developed more friction than the spring was designed for, rather than the spring having become weaker or was too weak to begin with.

 

IIRC, we replaced my buddy's TPS and it had a new spring.

 

Can't say I've run into that. The plunger on the TPS is a LOT weaker than the tension spring under the TPS.

 

Fullsize may have a point, the TPS plunger itself may be getting gummed up over time with carb varnish. I'll have to take an old one to the parts store and compare the plunger tension to a new one.