Pulsing from 1.5K to 2K
 

Hey You All,

I recently purchased my first Honda. It's a 1993 Accord LX two door with a 5 speed manual. It has 325,000 miles! I hear that it's 250,000 miles to the moon. Well, I've rounded the moon and I'm headed for earth! I hope to get to half a million.

When the car is warming up, the idle will very regularly pulse from 1,500 rpm to 2000 rpm. When it warms up, it's fine, it drops down to 900 rpm or so. I tried to see if there were any codes in the computer and shorted the blue plug under the passenger dash and the check engine light stayed on instead of blinking. Does that mean there are no codes? Anywho, just wondering if you all can help me out; it would be greatly appreciated.

Thanks!

-Red

The CEL staying on meant that no codes were stored.

I would start out by cleaning the throttle body and throttle plate (both sides). Use an old toothbrush and some throttle body cleaner.

The idle problem could be due to a faulty FITV. I would start the car with the snorkel removed from the throttle body. Then cover the lower port inside of the throttle body with your finger. Does the idle stabilize?

I had the same problem and crispin will chime in on this. Bleed your coolant system to get air out of it. Then set your base idle. That worked for me.

When you jumper the SCS connector, the CEL will turn on solid (not flashing) if there's no stored error codes.

Top of this forum there's a "sticky" thread called Common DIY or something like that. Look in there for a link about setting the base idle. There's a handful of things (including air in the cooling system) that can confuse the idle-control system.

Hey, i dont know if this will help u or not. My car did the same thing,i cudnt figure it out. then it was the gasket on the air manifold was leaking a little. and the ecu was showing any codes for it. also bleed the coolant system. it cud be that. hope this helps u