Alright, I have a 93 VTEC, I just had my ignitor module chip (inside the distributor) replaced the other day along with the ignition coil due to car dying while driving. Now its been a week and during a 45 minute commute, my car is jumping rpms. for example, my rpm need is rising towards 3000 rpm and then all of a sudden it jumps to 4000 rpm and then back to 3500 rpm. Does this through all gears and even cruising in 5th. Anyone have any ideas? Thanks.

 

I have the same problem. when I'm cruising in 5th, the car does exactly the same thing your car does. I took it to a shop, and the mechanic said that the only way he could test it is with a diagnostic machine, but the machine only work with the car sitting, not moving. The only way the problem shows, is having the car moving...

 

CHeck your plugs. I suspect it might be those. I have almost 100k on my car, so i'm a switch those out. I mean, I dont feel the engine when the rpms do this, it seems to be an electrical issue.

 

mine was doing it under boost, but it might apply to you cause it meant the timing was a little too retarted. try advanving it a little and see if it gets better. They might not have put it back at stock!