I have an 87' 4Runner with a rebuilt 22RE. It runs really good, except there is a stumble that happens when you slightly raise the RPM's past idle. After that trouble spot it goes back to running fine. Any ideas on what this could be?

 

can you describe it better? it could be timing.
does it do it while in neutral, engaged, or both?

 

It does it both. It happened one time while driving, and another idling in a drive-thru.

I put some injector cleaner through it. Not sure if it really helped. It comes and goes. I noticed that today its idling poorly. Tomorrow it will probably run fine again.