I just bought a 94 del sol si and its idleing funny..........

At first when I would start it up it would idle at ~1300 for about a minute and a half and gradually drop down to about 650ish. It would then bounce from 650 down to 500 and back to 800 then back to 650. I replaced the dirty cheapo filter on the sri with a clean cheapo filter.

Now when it starts its at about 1100, then it gradually drops to 750 and remains fairly stable. But today after driving for about 30 mins I came home, the car sat for about 15 minutes off, and then I drove about a 300 yards, came to a stop, and the idle dropped to about 500. I revved the engine to about 1500, and then it dropped down and stalled. It was a very "smooth" stall, it didnt hesitate at all, it was almost as if i had turned it off. I drove it again after this about a mile around the block, and it was doing ok, staying at about 750 the whole time.

I know this could be alot of things, but do any specific issues come to mind? What should I check/replace next?

Thanks in advance for any info.

 

What does the maintenance history look like?

Cap, rotor, plugs and wires
Fuel filter
O2 sensor
PCV valve
Valve adjustment
Cleaned the grounding points

Have you tried blasting some carb cleaner through the IACV to see if it helps?

 

first thing that comes to my mind is:
- Idle air control valve
- Vacuum leak

 

Yeah, if you don't know the maintenance history of the vehicle, I'd start off like the other guys suggested - normal maintenance items and work your way up from there. I'd probably go after the IACV before tackling the O2 sensors, grounds, or valve adjustment.

Before that though, tackle the normal consumables - - given the car's age if you don't know they've been replaced, you should do it now. PCV & Fuel filter are cheap and very easy to replace. Plugs, wires, distributor cap & rotor are relatively cheap and still simple to replace.

 

like ^^^^^

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B16B &raquo;</TD></TR><TR><TD CLASS="quote">first thing that comes to my mind is:
- Idle air control valve
- Vacuum leak</TD></TR></TABLE>

 

my homies DA would also idle funny similar to yours, it would idle at around 2500 then would drop to like 800, the needle would just be goin up and down. We just cleaned his IACV with and now it works just fine. ( carb cleaner )

 

https://honda-tech.com/zerothread?id=699787