Vehicle: 95 Accord Vtec, AT

I have an ldle problem that I was not able to find in the archives. I am not having any fluctuating or surging like I often read about. Nothing that dramatic.

After the car is warmed up to normal operating temp and idling nice and steady at around 750 rpm for about 10 minutes, the rpm then slowly climps to about 900-1000 rpms -- very slowly. It takes about 15-20 minutes to get from 750 to 1000 rpms. It never did this before. Btw, I did most everything the forum suggested, clean the IACV, FITV, TB, EGR valve -- replaced all of them with new orings and gaskets. Made sure all surfaces were clean and flat and smooth. Everything checked out but the problem is still there. I tested for vac leaks in the Intake Manifold but that checked out ok. I checked the throttle cable setting, cc cable, and the Tranny cable. They seem ok.

A Honda parts guy told me this was normal for high mileage vehicles.

The one thing I have not done was to recalibrate the TPS after having turned those rivet heads into slotted heads. Do I need to reset the TPS? I have not attempted to set the base idle or mess with any factory settings. The idle seems ok, it slowly gets to the 750 rpm during the warm up period. It just doesnt want to stay there forever. So, like I mentioned it will very slowly go from 750 to 900-1000 rpm.

Any suggestions?

 

"Honda parts guy" is a nitwit; this is NOT common on high milage Honda's.

The TPS shouldn't have any effect on this.

I do have several questions:
What is the cooling system doing while this is going on? Is the temperature remaining constant?

P

 

Make sure you have enough coolant in your system. My neighbor's Accord acted similarly and couldn't find out why. Turns out, he was lacking a ton of coolant in the system, problem solved.

 

X2.. Check coolant levels..

 

The temp is fine and stays normal, the usual needle position for Hondas at about 1/3 the way up the gage, i.e., slightly below the middle line.

 

I'm adding a slight bit of info here. I assume no one will read my post a second time. Not sure what is protocol on this site for adding info, if it is to be edited into the original post or as an add on. Anyway, for now here is the add on:

I'm not sure what the two lines on the tach stand for in between the zero line and the 1000rpm line? I looked in the sticky and did not find anything and my owners manual does not explain the markings either. It looks as if the first line past the zero is about 250/300 rpm, and the next line would be the 750 -- comparing those lines to the rest of the tach markings. If the second line past the zero mark is 750 rpm, then I'm idling at about 800rpm after warm up [using the temp gage as the reference], just a bit over the line below the 1000 rpm mark. Then it goes up slowly to slightly below the 1000 line, I'd say 900rpm. Overall it is increasing from 100 to about 200-250 rpm. That is the behavior of the tach needle and it does not deviate that I am able to tell, at least not yet. It doesnt sound stressed or smell hot, or anything like that. Coolant level is full. Not sure if this is something major, but I do not think its normal, and I need to keep an eye on it.