Hi all, first post here.

There's a litany of issues with this truck, but first and foremost is a rough idle.

About the truck:
79 SR5 (stock carb), bought it 6 months ago.
Previous owners: headers, no air pump, new wires/plugs & filters
Me: valve adjustment, front seal, timing, rebuilt carburetor (mostly new gaskets)

Does anyone know if the secondary barrel should be completely closed at idle? I can push mine down ever so slightly with the engine running and it causes the RPMs to dip quite a bit. It idled rough before the carb rebuild, now it's about the same if not slightly better. The hoses should be ok, and I just replaced the seal around the EGR valve.

These things seem finicky, but if anyone has some insight it would be greatly appreciated.

 

Yes it should be completely close and with the first barrel throttle plate fully open should open just a tiny crack...i believe vacuum takes over after that. I've been continually diagnosing my rough idle. Major things for me were PCV valve and hoses.

 

Check ur vaccum lines. And check ur timing

 

Thanks for the replies! I didn't see they were posted until now, but and update might help people searching threads for answers to a similar problem.

So, the rough idle has been fixed. The problem was the plate on the secondary barrel. I had to take the carb apart and re-situate the plate in the second barrel. With a good seal on the plate my idle problem stopped. For good measure I replaced the vacuum hoses with fresh ones.

 

seee