Need Help ASAP ( 91 accord idle adjustment )

[project-CB7]

I have been researching and used google alot, even went back to the autozone for quick feed back.

i own a 91 accord but recently it's idle speed started jumping from 900rpm to 1500rpm.

- i cleaned out IACV with carb cleaner and found a spare one at a car junk.
- took off the FITV and replaced the Valve inside from an Accura Legend and rubber gaskets as well.
- got an OEM thermostat from honda dealer
- replaced EGR gasket
- found a map sensor on a car junk and replaced it too
- tried adjusting the timing
- got new NRG sprak plugs
- looked for an air bubble and bled the coolant
- got a new PCV valve

and after all of this im about to give up on my cb7 because the idle is not stabilizing.

What am i doing wrong? did i missed something?


WHat is that thing behind the plenum, and doest it play a roll in idle control? is it some sort of a vacuum solenoid ??

[old honda tek]

loosen your accelerator cable slightly , its to tight, and that soleninoid is for the rear mount...

[DRAGON JOEY]

I see you still have your cruise control, try checking the vacuum hose that goes to it, mine was doing the same thing a while back and it ended up being the vacuum hose to the cruise control. Hope this helps.

[wed3k]

if everything looks fine, look for a vac leak. sometimes the idle adjustment screw backs out as well.

[bcjammerx]

if everything looks fine, look for a vac leak. sometimes the idle adjustment screw backs out as well.

oh hells yeah. Mine would back out every 2-3 weeks...I was going out of my mind! Had to replace the gasket that goes with the screw...errr...well...actually I just put weak locktite on it...that worked too

[project-CB7]

ok, i checked my accelerator cable and it seems to be fine, idle adjustment screw helped a little. I found one of the faulty vacuum lines and the rpm stopped bouncing, however after the car is warm and you give it gas it tends to hold the rpms for 2-3 seconds than its drops back to idle speed. That doent seem normal, the way the engine sounds. ( i have stock engine with a few bolt ons)

i hope i didnt confuse anybody ( sometimes my English is off a little, im from Europe so dont mind my grammar =] )

[Cobalt]

Hmm, My Cobalt holds RPM's sometimes when in neautral but my CB7 hasn't seemed to have that issue... I honestly dont know what the issue is.

[project-CB7]

I went back to the vacuum lines ( engine running ) i heard a hissing sound behind a plenum and i found a missing line, so me being clever trying to fix it, i put a plug in that line.

the bottom line is plugged and the top line runs back to that solenoid i asked earlier. i dont know if its supposed to be plugged but it did the trick of fixing the bouncing rpm.

[project-CB7]

===>
during my quest on fixing this "tiny idle problem" i found a strange fact.

so in the end the cars runs great, but thats up until i turn on my A/C or fan and the idle begins to bounce and down even after i replaced some parts and did what i could to the best of my tiny knowledge. PLZ HELP

WTF IS GOING ON. i turn on my fan and the idle begins to bounce? why?

[wed3k]

tried cleaning the throttle body? whats base idle? (after you unplug with iacv)

[stretch JDM]

===>
during my quest on fixing this "tiny idle problem" i found a strange fact.

so in the end the cars runs great, but thats up until i turn on my A/C or fan and the idle begins to bounce and down even after i replaced some parts and did what i could to the best of my tiny knowledge. PLZ HELP

WTF IS GOING ON. i turn on my fan and the idle begins to bounce? why?

its pulling more amps. that causes the idle to change.

[wed3k]

no it's not...the ecu detects the a/c clutch switch kick on and it raises the idle via iacv for compensation.

the alternator "pulls" in amps, the ecu also monitors that.

[project-CB7]

tried cleaning the throttle body? whats base idle? (after you unplug with iacv)

i pulled my throttle body and cleaned it out ( looks brand new )
my base idle is set at 800rpm (iacv plunged) and it works fine, when i pop the car in neutral and turn on my fan the idle raises to 900rpm and bounces to 1500rpms.

unplugged last time i remember was like 500rpm .. honestly i dont remember. why did you ask?

i wonder if it has to do with my ECU?

[wed3k]

800 base idle is too high, it should be around 600 or 650 max.

[project-CB7]

800 base idle is too high, it should be around 600 or 650 max.

yeah but high base line rpms should not affect the idle speed when an electrical component increases a load on the alternator, right?