another tricky hunting idle

[civikfx]

ok. yep im new and i know this has been asked many times before but i think mine is a little different. so just bought a 91 civic sedan and has the typical hunting idle. so let me pi ur brains for knowleg, in the last week i have replace iacv, map,and tps. my qs is that when i changed these parts then reset the ecu i get no change. idle still jumps from 1k to 1500 once warmed up, however if i remove the vacume line from the map and plug it, it idles perfect. why??? i know ford chev ect cars but these hondas confuse me. i need help. oh also i just blend the coolant and no result

 

[RonJ]

Is the LED on the ECU blinking any CEL codes?

What trim? Any mods or is it stock?

 

[civikfx]

hmmm. well i dont have a clue of where to find the ecu. since im new to hondas and there is no mod as of yet. std 5spd 1.5 motor not sure what trim. think its lx but there is no badges on it.power everything if that helps. just got this for a gas saver and my buddy has a civic with a swap so ithought it would b a good first time tuner car. i know go ahead and laugh its ok

 

[RonJ]

 

[civikfx]

oh man, thnx so much. i didnt want to throw any more parts till i knew what was wrong. now i was disconecting the battery but can i just unplug the ecu to clear the codes? im hopeing if i get this fixed 2day i can put some drop to the car.

 

[RonJ]

First check for CEL codes. If you find any, write them down and then reset the ECU by removing the Hazard lights fuse in the hood fuse box for 3 minutes or more. Then drive the car to see whether any of the codes repeat. Post any codes that repeat.

 

[civikfx]

ok so i reset tthe ecu and cant get any codes, unless i make it throw a code by pinching the only vacume line that will let it idle at 700rpm which is the map sensor vac line. a code #5, also i went out today on a 5min drive, shut it off and would not start i had to wait about 5-8 min then started just fine. however that was before i made it throw a code. this is a becomeing iratateing to me. oh it also idled down to 500 on its own before i turned it off when it didnt want to start. hmmm