1987 Accord won't idle???

[TheHondaMan]

I got a 87 accord (carb) that I rebuilt the engine when I got it, installed it and it won't idle when it's warmed up. I don't know if it ran good before I rebuilt the engine. I've tried adjusting everything I can, alot of the parts are brand new, minus the carb and sensors.
I figured that it needs more fuel, because the less air it has the better it runs. It takes a little for it to start hot or cold and idles fine when it is cold. The float is okay, fuel filters are brand new, put in fuel system cleaner, tested the fuel pressure and it was 2-2.4 psi, the fuel pump connection is good and clean, gets good power and ground, could the pump be bad?
Also I tried driving it and it won't keep accelerating after 3K rpm, the power just goes away. This is my first carbed honda that has had any problems. Anybody have any ideas?

[stephensimmons]

How do you mean the less air it gets the better it runs? how are you retricting the air?

[A20A1]

Check for vacuum leaks from the intake manifold gasket, vacuum lines, and carb gaskets.

If it's not a vacuum leak check the float level, make sure your booster venturies are tight.

Check to see if your choke is opening and that your hot air door is not stuck open.

[TheHondaMan]

I mean that with the air filter and cover off it has a harder time running than with it on and also when I close the choke door a little it starts to idle better. I checked for vacuum leaks and can't seem to find any. When you say "booster venturies" your talking about the brake booster hoses, right? All the gasket are new. It just seems to not want to idle when it's warm only, it acts like it is trying to, not like a vacuum leak, but like it needs more fuel or less. The choke and hot air door are working fine. Thanks for the fast response.

[TheHondaMan]

Shouldn't the fuel pressure be more like 3 PSI, not 2-2.4psi? Could the fuel pump strainer be clogged?

[stephensimmons]

It should sill atleast idle even an 2psi. you git a problem in your carb somwhere. And if you can close the choke with your hand or take some carb cleaner and spay in it while its running and it runs better then ether you got a vaccum leak or something ie wrong with your carb. exspecially sence you say it wont go over 3000 rpms.

[TheHondaMan]

I didn't get a chance to look at it, but I think the secondary barrel in the carb doesn't come on when I accelerate. Where are some common places for vacuum leaks for these engines? The carb gaskets are brand new, and intake gasket.

[stephensimmons]

I usually use carb cleaner and spray it on the vaccum lines and around the carb but i wouldnt advise that because that could be very dangerous! the other way is to listen for a hissing sound when its running and also inspect all your hoses. And also check your pvc valve.

[TheHondaMan]

I just took out the PVC valve and put a cap on the intake nipple so I could rule that out. It was making a hissing sound before and I just took all the diaphrams and vacuum hoses off the driver's side of the engine (where it was coming from) and check them, some of the hoses were loose on the ends and leaked. The sound is gone, but it still doesn't idle. That is what is so confusing to me.

[stephensimmons]

Ok try starting the car and rev the engine around 2500 RPMs and close the choke with your finger and the engine will try to stall when doing this, but dont let it stall when it just about stalls let the choks open till it picks back up and do it again. Do this bout 4 or 5 times and see what happens.

[TheHondaMan]

Ok try starting the car and rev the engine around 2500 RPMs and close the choke with your finger and the engine will try to stall when doing this, but dont let it stall when it just about stalls let the choks open till it picks back up and do it again. Do this bout 4 or 5 times and see what happens.

Okay, I'll try it tomorrow, do I do it when it's cold or all warmed up?

[stephensimmons]

I would let it warm up because i dont like reving a cold engine.

[TheHondaMan]

Okay, did the test. When I closed the choke it just about died, then let it open and made a hiss noise as it sucked in air and went back up to 2500 rpm. I did it about 6 times and it did the same thing. Also, the float level screw is leaking (just started today, so not related to the idle), can I take the screw all the way out and put thread sealer on it, or is there better way? Thank you.

[TheHondaMan]

Also which is the idle boost diaphram, is it the one on the passenger side of the carb?

[TheHondaMan]

Any input?

[greentee76]

Have you checked the slow idle mixture solenoid on the rear of the carb? If this is not working it will act like you describe. It will idle fine on cold idle because you are not actually on the idle circuit. The actual idle circuit(fully warmed) requires the solenoid to work correctly.

[TheHondaMan]

Yah, the solenoid was bad and I replaced it with a good one, but still the problem. Where does the signal come from for the solenoid?

[TheHondaMan]

Hey, found the problem. The idle solenoid was bad, I found a good one at a wreaking yard, but the connection was bad, so I just spliced my connection to the new solenoid. There was a vacuum leak that caused the really bad idle problem, but today, I looked at the solenoid and the wire broke off, reconnected it and now it runs and idles perfect. It wasn't just one problem, but more like 3 different problem, but all came back to the first one. Thanks guys for all the response.

[A20A1]

Also, the float level screw is leaking (just started today, so not related to the idle), can I take the screw all the way out and put thread sealer on it, or is there better way? Thank you.

No thread sealer... you need to remove the top hat, remove the pin holding the plastic float then screw the float valve out from the base of the top hat... there you will see 2 o-rings. Replace both of them with fuel safe o-rings.

http://www.3geez.com/forum/attachment.php?attachmentid=3341
http://www.3geez.com/forum/attachment.php?attachmentid=3987


Be careful not to break the float stop as that will help keep the float valve needle from falling out when you reinstall the top hat.

[TheHondaMan]

Well I got another problem. I had it running and idling perfect. I took it out and drove it alot, but it died at a couple stops. I looked and the float was a little low, so I reset it, but didn't help. Slowly it started to idle rough, and now it just wants to die. It only wants to die when the choke is 100% open, it idles okay when it's like 80 or 90% open. The Idle solenoid is good and working right. It just slowly dies, like it's running out of gas.
About the float, I never fixed the leak, it just went away. Could it leak internally? It stopped leaking and it was running fine so I don't think it has to do with anything. I really need some help, just through out ideas?

[TheHondaMan]

Please, I need some help. What else in in the idle system besides the slow idle solenoid and air door. Could the Air Intake sensor be bad? How do I test that? All I know is it needs more fuel. I took the top of the carb off, replaced the gasket, and cleaned out all the passage ways. Another thing is it's hard to start when it's cold, it doesn't go straight up to warm idle, it stays at 1300 RPM and after a minute goes up to normal 2400 RPM. Please, just through out some ideas.

[Xaisk]

Ive had the same issue since I got my 88 Accord back.

I havent been able to fix it so im just replacing the carb with a Weber.

That should clear the problem.
These Keihin carbs are VERY touchy and difficult to work with.