19 replies to this topic

[esty]

If it's capped, try uncapping the fast idle diaphragm, the black plastic module on the carb on the back left (when you're at the front of the car facing the firewall). I was stuck on fast idle the first time I devacced because of this. The car was in fast idle mode and couldn't kick down because the fast idle diaphragm couldn't move. Uncapping the ports allowed the diaphragm to move around and kick down.

Also check the idle speed at the idle control screw, as well as the tension of the throttle cable (there should be none, and lots of free slack. You should be able to move the cable around by about a half centimeter before it puts any pressure on the throttle at all).

is this what you're talking about....you canb see how i have it loop'd...ui have tried removing that small piece of hose but it didn't change the idle...



there is a lot of slack in the throttle cable...it's not holding the idle open at all and the idle control screw(s) is out all the way, not touching on either side of the carb

[DarkHand]

All these live pictures make it pretty easy, thanks!

Yep that's the one. Try this: With the car running, connect a vacuum hose to that fast idle diaphragm again, just the port on the right (looking at the carb from the angle in that last pic), and suck on it! While holding vacuum, blip the throttle a little. This will make sure you're off the fast idle cam in the carb by applying vacuum to the diaphragm. The left port (further from the carb) turns fast idle on, the right side (closer to the carb) turns it off. If still no luck, try holding the choke plate completely open and blip the throttle... Perhaps the choke isn't opening enough. If that still doesn't drop the idle after all of this, there's probably a vacuum leak somewhere. Double check all your vacuum caps and make sure none of them have popped... The vacuum can be so strong on some of the ports that the cheaper colored caps can break. If still no luck, try pulling the throttle cable completely and see how the car runs. You wouldn't believe how sensitive the throttle can be.

Also try disconnecting the AC idle boost vacuum port if you haven't already. Just pulling at straws at this point, but maybe the AC idle boost is on.

Edited by DarkHand, 14 July 2007 - 02:46 PM.

[esty]

All these live pictures make it pretty easy, thanks!

Also try disconnecting the AC idle boost vacuum port if you haven't already. Just pulling at straws at this point, but maybe the AC idle boost is on.

i've had the throttle cable completely off and that didn't lower the idle...what/where is the AC idle boost vacuum port

BTW...i really appreciate the help...

i bought a new CRX in 87 and loved it....i just didn't realize how much i loved it until i traded it for a new 89 accord....i was lucky to find this one, original & unmolested and i suppose in the scheme of things, getting the carb properly adjusted is minor...it would help if i was a mechanic and knew more about them....

i have several webers that i've used on a few of my BMW 2002's and ordered the adaptor plate to try one but it's difficult for me to imagine the car will run better than it does now...it's very fast from start to finish

again...thanks for the assist

[DarkHand]

The AC Idle boost is another vacuum line that applies vacuum when you turn on the AC. This boosts the idle to keep the engine from lugging or stalling when you turn on the AC. It's the small solenoid on the firewall on the drivers side of the car... In your last picture it's the little module right above the line of your green arrow, bolted to the top of the firewall with a little red wire going to it. After looking at the pictures more though it looks like you already disconnected it when you did the devac, so that idea's probably out. Give the others a try though.

[zakats]

I think that its a natural, first instinct that one would want to cap off every, or nearly every, vacuum port but this isnt the case. nearly all of those ports on the base of the carb (esp. those connecting to thermal devices whatever they are) dont require caps but wouldnt make any difference.

try backing off all of the adjustment screws on the carb- a/c, idle, ect... unless uve already done that.
then go around uncapping the vacuum caps and see if you have any change in idle and check with ur finger to see if its venting much vacuum. if it is- then you should probably keep that one capped- otherwise, you should keep it open(dont apply this to the firewall side of the carb. ex-the 3 or so vac ports on the top, firewall side of the carb.)

most notably you need to keep the bowl vent(s) open on the driver side of the carb- those will encourage flooding.

theres a lot more that could possibly need addressing that is covered under the old writeups found conveniently using the search function

btw you can remove that big metal container thing that mounts with the 2 10mm bolts on the pass side of the intake manifold. it serves pretty much no purpose.
also you want to make sure you have the bottom vac port on the furthest driver side intake manifold runner, white, plastic valve (thing?) I dont recall what it used to be for, but it doesnt do a damn thing anymore! cap it off!
double check your larger vac ports on your intake manifold- they tend to pop off occasionally
-zak