83 High Idle in Park

[koppenhaver]

i just got a new carb for my 83 2.8 l, was the first time i heard it running, it seems to want to idle high in park, but when i switch gears it drops cant see how much it actually drops cause it has no tach. i am installin one though to see for sure. would there be a reason it would do this?? any maybe simple solutions to this issue.

also i seems to have a small miss when idling, when i give it some gas it seems to go away. i just changed the plugs and wires on it, next is a new coil.

just trying to get this girl running like she should. thanks for the help in advance!!

 

[kimcrwbr1]

Are you still using the computer?

 

[koppenhaver]

computer as in what? everything is the way it came from the factory engine wise. if that helps

 

[AndyB.]

Did you set the three idle speeds? Adjust the idle mixture?

 

[drsvox]

Look at my post Original Decal Repro in the 2.8l topics. There's an ECVI sticker there for the 2.8 which shows idle speed settings.

Also, read the 2150 rebuild article in the tech library...should tell you how to set your idle speeds.

 

[kimcrwbr1]

Yes there are three adjustments but the computer controls idle speed. First thing is to pull the spout wire and check ignition timing is exactly 10 degrees BTDC. Plug the spout back in and adjust the idle air needles after prepping the motor. Everything needs to be plugged in and disconnect the battery for 20 minutes to reset the computer. Bring the engine up to normal temp and check the choke is fully open. Have someone press on the throttle and you should see the idle control motor fully depress. When that happens disconnect the idle control motor and let off the throttle. On the side of the carb is the antidiesel screw what would normally be the idle stop screw adjust it for around 650 RPMS it should be barely running. Then adjust the idle air needles for the highest possible rpms. Do both needles a couple times until the rpm will only drop when you turn them in normally around 3 1/2 turns out from lightly seated. Then set the idle speed for around 650 rpms again and then plug in the idle control motor and the computer should take over and control the idle speed. To set the curb idle turn the engine off and the idle control motor should fully extend, Unplug the idle motor again and start the motor. To set the curb idle speed loosen the screw for the motor and move the position of the motor for around 1150 rpms. Locke the motor down and plug it back in and the computer should again take control of the idle speed. Then it is a matter of adjusting the choke thermostat and high idle cam on the choke. The engine needs to be cold and can be tricky to get it right. Pull the air cleaner but leave the intake air senser plugged in and jus set it aside. Push the throttle and the choke shoud fully close. Start it and the pull off should open the butterfly about 3/16 inch and the engine should idle around 1500 rpms after you tap on the throttle. To adjust the high idle there is a screw that points straight back toward the firewall, you adjust the screw when that is on the upper cam only and wait a minute or two as the engine rpm will climb as it warms up. Watch the choke it should fully open after about four or five minutes. Alot of info here so just do it in the proper order
1- confirm base timing
2- adjust needles with the idle motor disconnected (highest possibe rpms or vacuum pressure)
3- adjust the curb idle speed
4- adjust choke pull off, high idle speed and choke spring tension