Building suspense does not mean keeping the reader uninformed. Some of the best suspense is built by alluding to something that might happen, even if it doesn’t. One thing to avoid is blindsiding your readers with something that hasn’t been hinted at in some way.
For example, if you’re writing a murder mystery, mentioning the guilty party in some manner during the story before s/he’s revealed as the culprit is essential. The same principle applies to various other situations as well.
Often more information is more suspenseful than not enough since feeding the reader’s sense of anticipation is the key.