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locknload68
09-24-2002, 11:30 AM
I need a very good description of all the components of the choke system. I need vacuum lines(I'd also like to know how much vacuum they should have and when they should have it), what parts open the choke, also, there's a linkage that connects to something below the choke that I can't see, any info on this will be helpful.

The reason I need all this is cuz my choke is screwing up my idle. The car will idle around 2000 rpm when I first start it (I know this is normal), but it stays there. It's not just the idle cuz I can go down the road without my foot on the gas pedal and the speed just stays the same if the road is flat. It continues to do this long after the car is warmed up.

I was messing with it the other day cuz I wanted to try and fix it. I thought it was something to do with the fast idle unloader. However, I used my finger to open the choke ALL the way and the idle went down to 750 after I blipped the throttle. If I let go of the choke and blipped the throttle again, the rpms went right back up. So, I really need info about the choke and how I can get it to open all the way.

Sorry about the long explaination, I just wanted to let everyone know exactly what is happening.

Thanks

Bob K
09-24-2002, 12:02 PM
Your choke unloader diaphram is rotted-out. Gotta buy a new one. Just take a piece of vacuum hose and place it on the nipple and suck. ( sounds provocative:-) )

Just see if it will hold vacuum. ( it won't ). Actually , while you are at it, check all of your diaphrams. If yours is like mine, the aircleaner diaphram is gone as well as a couple of others. Your car will idle much better when you fix these vacuum leaks. Be aware, most of these diaphrams are dealer only parts.

Bob K

DanG86LX
09-26-2002, 09:50 AM
I think the choke heater is the culprit. The bimetallic spring inside is the one that keeps the choke flap closed. With engine warm, the choke flap should be VERTICAL.
- Check there is current going through the heater. Disconnect the wire (firewall side) and insert a multimeter (set on 10A input). Start engine (cold), it should read ~ 0.5A but after 1..2mts it should jump to ~1A and then decrease gradually to 0.5A within another 1..2mts
- If previous test is ok, open the heater (drill 3 rivets) and inspect the bimetallic spring inside. It might be broken or defective..

With engine warm and at idle, all those vacuum lines (#18, #19, #26) should have vacuum ~18inHg.
#18,#26 receive vacuum from under the throttle through internal carb passages and choke opener (http://87accord.com/carbpage.html, Right side of carb, "G"). U may unplug the two lines from choke opener and plug the opener orifices with ur fingers, the opener should retract completely (lever sits against carb housing) but that would open the choke flap at ~ 45deg (1/8" between top of flap and bore).
#18, #19 are coming from a 3 way thermovalve and goes to fast idle unloader (carbpage.html, Rear side of carb, "O"; Right side of carb, "A,B") to release the fast idle cam (behind the choke heater) in two steps according with coolant temp:
#18 gets vacuum above 15..20C
#19 gets vacuum above 60..70C

Hope that helps..

POS carb
09-30-2002, 07:25 PM
take off the vacuum hose to the fast idle unloader and see if there's any vacuum there. if there is vacuum then it is probably the diaphragm as mentioned, if not it's disconnected or your thermovalve is stuck, follow the line, it goes down to the rear of the manifold (#18 I think it was). You can always do a temporary fix and just hook up constant vacuum to the unloader.