Out of ideas on this stupid idle

We may earn a small commission from affiliate links and paid advertisements. Terms

90sihatch

90sihatch

Senior Member
Obd0 92 ls in a 90 si hatch. Alright so I have always had idle problems since the swap, but after changing the radiator fluid for some reason it's really out of control now. At start up the car will idle around 2500, and after getting warmed up it will either surge from 1000 to 2500 or just stay at 2500. Before the car would surge a little, but never this bad. I have tried about 3 different IACV's, tightened the thermo valve, and messed with the screw a lot. The thing really pisses me off because with hasports and a straight pipe(soon to be fixed) that high of an idle is unbearable. Any more ideas will be appreciated because not too many mechanics around here mess with this kind of stuff. thanks
 
i never fucked with my thermo valve, i just replaced it. might try that.

check for vacuum leaks too.
 
I am not 100 percent sure, cause I am new to Honda engines, but a local friend told me one time that if you have air in your cooling system it will cause a rough, unusual idle. He mentioned how to get the air out, but I don't remember exactly. Seems like there is a plug somewhere near the thermostat housing that you remove or something, Sorry, I can't be more helpful. Maybe you can check on this possible idea. I will try to contact him and will be back to post just how you "purge" the air out of the system.....
 
yup absolutely, bleed the system and that may offer some relief.
 
yeah im with these guys, i purged the air out of my rex and it ran alot better. You even said you changed the coolant. #1 thing you always check after you do work on your car and it is messed up afterwards??? GO BACK TO THE SOURCE OF THE REPAIR DAMN autoshop 101.
give it a shot it should be fine, and coula been part of your surging idle in the first place.
 
Well the reason I changed it was because I had a leak in one of my hoses. While replacing the hose all the coolant came out anyway, so I changed it. Where is this purge valve?
 
Its a nipple bolt (like those used to bleed brakes) near the thermostat.
 
yeah im using obd0 alternator and ecu, but I think I have a bigger problem than that now. While i was putting the purge screw back in the damn thing broke the thermostat housing. Just took a big piece of metal right off. So if anyone has one of these for sale I need it.

But just out of curiosity, why do you think I would have a vacuum leak from converting?
 
well i had the same thing and i just changed the whole throttle body and it went away check ur idle control valve in the side of the throttle body
 
You must log in or register to reply here.
Back
Top