Questions and Answers

Honda Civic Shuts Down At 3,500 rpm Q. Hi, I have a 1994 Honda Civic SI with the 1.6 liter motor and a manual transmission. The car has about 160,000 miles on it. I have an intermittent problem that I am having trouble tracking down. Most of the time the car runs fine and pulls strong. But about once a day, when accelerating, when the car hits about 3,000 rpm it's as though it has hit a rev limiter and it will not rev past about 3,500 rpm.

That's the best way to describe it. I don't get a CEL or any codes. Turning off the key and back on again makes the trouble go away. And then it accelerates fine. I put new cap, rotor and plugs in and the problem went away for a few weeks but has now surfaced again. Some have suggested the coil or one of the sensors may be bad but I am not sure where to start. Any suggestions?

Thanks for you time...

A. In this case I would have to look at the Variable Valve Timing Control system.

Valve Timing Control
The PGM-FI system monitors the Valve Timing Electronically Controlled (VTEC) System. By monitoring various engine sensors the ECM can determine when to activate the hydraulic components of the VTEC rocker assembly to engage VTEC and similarly can verify this function by monitoring the VTEC pressure switch.

The VTEC usually kicks in at about 3,000 to 3,500 rpm so if the PCM sees it's not working, it limits engine rpm. A code should set in the PCM but it might not be a 'hard' enough failure to set a code.

You have to be very careful when checking this system since actuating the VTEC system at the wrong time could cause severe engine damage. I would recommend taking it to a Honda Dealer and letting them drive it with their scan tool connected so they can monitor the VTEC operation in real time and see exactly what it is doing, or not doing.