Whats the next step after RCM and CPS. The cps was changed out yesterday, on the freeway in LA today and the engine dropped to idle. Had to turn off and restarted and off we go with no problems this morning. Cant wait for the drive back. This problem happens almost daily. Pulled the RCM( as outlined by tighed1) 2 months ago and soldier joints were cracked as described . Resoldered them, same problem. Desoldered and resolder, same problem. Resolder everything on the relay, same problem. Cleaned relay contacts 3 times. Relay seems to only switch when air pump is operating on cold starts. Pulled RCM out after test drive and the relay in question was no where near as hot as the other relays. How often does this relay open or close? Resoldered joints again to confirm good contact last week.