erratic idle when cold, in park but when in neutral idle evens out??????

[1988]

This morning when it was cold out i noticed that when I started my EFI accord the idle was erratic. It was going from say 800-1500 up and down, up and down . I noticed what when i put the car in neutral the idling would even out. Any ideas on what this could be?

[1988]

This morning when it was cold out i noticed that when I started my EFI accord the idle was erratic. It was going from say 800-1500 up and down, up and down . I noticed what when i put the car in neutral the idling would even out. Any ideas on what this could be?

[ghettogeddy]

one post sh-oudl be enough
electronic choke might be going also it might just be a vacuum leak

[ecogabriel]

Manual or auto?
Mine did that (auto); in D it would stop. I had a vacuum leak (power brake booster)

[1988]

its an auto. was it the brake booster itself or a vacuum line?

[Dr_Snooz]

Vacuum leak or low coolant.

[Demon1024]

dont forget to check the Cold idle valve. little buggers



Vote for demofix

[forest1686]

mine is a manual and does the same thing when cold. Stops when warmed up. How/where do you check for the vaccum leak? Where is the cold idle valve?

[Catalyst]

I'm voting low coolant / air bubbles in the cooling system. Does it overheat at all? Do your cooling fans come on like they should? You should try to bleed the cooling system, and see if that helps.

[forest1686]

wow, yes it overheats...........what is the best way to bleed the system?

[w261w261]

What happens on the f.i. engines is you have an idle stabilizer valve, which gets faked out if there are air bubbles in the system. You get those bubbles by being low on coolant, or not bleeding the coolant system. There's a little bleed valve by the thermostat. There's also a ton of instructions on here that will explain how to do it. Since you're a new user, now's the time to learn how to use the "search" function. Also, there's some "how to's" threads. Don't be afraid to just dive in, everyone started at the beginning once. For instance, under the "how to" section, go to this page, then click on the link in the message. Or do a search on "bleed valve," or "bleed coolant" or somesuch.

http://www.3geez.com/forum/showthread.php?t=6572

[1988]

I have seen multiple suggestions on how to fix this problem from searching this forum. I cracked the bleed valve on the thermostat and there didn't seem to have any air in the system. I then took of the intake piping and cleaned the throttle body and the small port on the left side. Today I noticed when the idle wasn't bouncing up and down but I noticed that the idle was now around 1200 rpm rather than 750. I tried hitting the gas a few times and also drove the car for a while but once I am idling the car will now stay at 1200. Ayn ideas?

[forest1686]

Thank you very much! That has been bugging me for so long and it is really a pretty simple thing.

[Catalyst]

I have seen multiple suggestions on how to fix this problem from searching this forum. I cracked the bleed valve on the thermostat and there didn't seem to have any air in the system. I then took of the intake piping and cleaned the throttle body and the small port on the left side. Today I noticed when the idle wasn't bouncing up and down but I noticed that the idle was now around 1200 rpm rather than 750. I tried hitting the gas a few times and also drove the car for a while but once I am idling the car will now stay at 1200. Ayn ideas?

Are you sure you have an adequate amount of coolant? Are you getting a PGMFI light? Still sounds like a coolant issue to me. Does it overheat? Do your fans come on when they are supposed to? Even if there aren't any bubbles in the cooling system, an inadequate amount of coolant will cause the erratic / bouncy idle issues, and is very common in these cars.

If you are positive your cooling system is functional, its time to search for vacuum leaks.

[Dr_Snooz]

I have seen multiple suggestions on how to fix this problem from searching this forum. I cracked the bleed valve on the thermostat and there didn't seem to have any air in the system. I then took of the intake piping and cleaned the throttle body and the small port on the left side. Today I noticed when the idle wasn't bouncing up and down but I noticed that the idle was now around 1200 rpm rather than 750. I tried hitting the gas a few times and also drove the car for a while but once I am idling the car will now stay at 1200. Ayn ideas?

When you open the bleed bolt, coolant should come out in a steady stream. If it doesn't come out at all, then you are likely low on coolant. Check the overflow tank and the radiator (not when it's hot!) for the correct levels. If you top off the radiator and still don't get any coolant out the bleed bolt, then you'll need to start it. Coolant will shoot out like a geyser then, so be standing over it to turn it off as soon as it starts.

If it's idling consistently high, then just back off on the idle screw.

[ecogabriel]

Another place that may explain high idle is the cold idle valve. It is attached to the throttle body between it and the firewall. It has a cap fastened with two screws. If the valve fails in closing completely once the car is warmed up (the valve has two small water hoses to sense temperature) then it may be adjusted to give a lower idle speed. That valve may be adjusted if the idle fails to go down, although the service manual says nothing about it; instructions can be found here in the forums.

[1988]

thanks guys. after the last post the car evened out a bit. When I bleed the coolant from the thermostat bleeder valve the coolant came out at a steady flow. The fans only come on when its really hot. To me they come on a lot less than my 92 Accord. I added a lot of water to the reservoir tank so maybe that was the culprit.
I will update soon.
On a side note, just recalling last winter, do all of the 3g Accords take a long time to warm up in the winter. This car seems to take forever when its freezing out. My old 92 would warm up in like 5 min this car seems to take forever. It has a new water pump and thermostat. Any ideas on that? Any way to improve it?

[1988]

after filling the coolant res. the problem persists. even after driving it for a while and then putting it in park the car will go between 800 and 1400 or so

[1988]

I changed the fast idle control valve and the car runs like a top again.
thanks guys