I've got this wierd issue with my 99 Accord (4-cyl, EX, manual). About 3-5 mins after startup, maybe a mile into a drive, I get a very slight hesitation from the engine, almost like it's misfiring for a rpm or maybe just a few cylinders of an rpm. It's very short, the car doesn't shudder or anything, it just feels a little like I let off on the gas a little. It happens every time without fail, except when the engine is already warmed up and just turned off for a few minutes. I've cleanup up the plugs, distributor, wire contacts, I don't think it's an ignition issue since the car has never missed at all and gets excellent mileage. It seems more like it's the CPU or something adjusting sensors or something in response to the engine warming up. It usually happens at or around just above the C mark when the temp gauge is rising to normal operating temp. I thought maybe it would be the thermostat too, but I don't see how it opening would make the engine hesitate. Any ideas?

 

I don't recommend you "Cleaning" the plugs, I would replace them......check your distributor for worn out contacts, cleaning it won't do much if the contacts are worn out IMO.....check for vacuum leaks, injectors, and air filter.....see what happens

 

My 99 4 cyl has done this since I bought it brand new. I think it's the computer going from open loop to closed loop since it occurs right when the motor hits normal operating temp.

 

Really? If that's the case I probably won't worry about it. Thanks!

 

Yep, seriously. Nothing to worry about at all.

 

mine does that its a 92. i think its my iac valve. once it warms up it stops balking like a baby. there is a screen in it that gets gunked up. throttle body cleaner can clean the screen. i just havent gotten around to doing it.

 

I had a '93 for about 4 years. I never really noticed anything. The only thing wierd it ever did was make a funny rattle/humming noise when the engine was under a heavy load, like gunning it up a hill or downshifting to 3rd or 4th and hitting the gas on the freeway to pass. It did that from the day I bought it to the day I sold it. The 6th gen makes no such noise, instead, it sounds like a little diesel with all the clicking and clacking when it's cold. (Don't tell me to adjust the valves or seafoam it, I already did. This engine is just noisy when it's cold.......).

 

90-93 Accords will develop a slight stumble around 1800 RPM when the EGR ports in the head and intake manifold get clogged.