My motor n carb are throwing me for loops!

[jstruthers92]

Alright il give you guys some backround. I bought the truck a couple weeks ago n it had a high idle n sticky throttle problem so chasing that ive replaced the idle speed control motor, throttle position sensor, and rebuilt the carb last weekend. the throttle doesnt stick anymore but it just doesnt seem to want to run right all the time. For the life of me i cant get the carb adjusted where it needs to be and everyday i find myself tinkering with it. I know everyone says turn the screws out 1 1/2 turns out start it up and go in from there. My truck must be an exception because it wont even start that far in. i have it around 3 turns out and it runs decent still has a wierd idle like it goes up n down and i play with the screws n i dont seem to get anywhere. Once i think ive got it perfect i take it for a longer drive or drive the next day and its off. ive done it by feel n ear and with a vacuum guage. when i think i have it its good for a little bit and then i notice the idle go off a little and my power sucks. Before i rebuilt it i had it on the highway doin 65 and it was running like a champ minus the stuck throttle and now i just can seem to get it back to where it needs to be. I didnt replace the jets, just a basic rebuild. I didnt even mess with the adjusting screws when i had it apart.
Ive tried doing it on my own so obviously i need some help. Thank you guys

 

[kimcrwbr1]

You need to adjust the needles different. Turn the needles out 3 1/2 turns preadjustment. Bring it up to temp first and then unplug the idle speed motor then adjust the needles for the highest possible rpms or vacuum pressure then plug the idle motor back in it should idle righ down. When messing with the carb you need to have the IAT senser plugged in on the air filter housing if you run it with a sensor unplugged you will need to reset the computer by disconnecting the battery for 1/2 an hour and start the process over. To adjust the curb idle turn the motor off and the idle motor will fully extend that is curb idle, unplug the idle motor and start it up adjust the position of the motor around 1150 rpms lock the motor down and plug it in it should idle right down. GL

 

[wildbill23c]

Is there a way to adjust this with that sensor on the air filter housing missing? I've had the same issue with 2 different carbs. I adjust it, and it is ok, then after I drive it for about 10-20 miles it is idling way too high, but if I turn the idle back down then the next day it doesn't want to start. Seems like there is something that I'm missing or not doing right. I started with the 3-1/2 turns out, then went from there on a warm engine, after a long drive its idling high again, the idle motor is inop as is most of the other sensors on the vehicle, and it won't idle worth crap with either carburetor, its like its always revving up or trying to die no matter what the settings are. There's like no in between its either too low of an idle and will die or it idles way too high.

There's also a 2 pin plug on the back of the carburetor, does it make a difference if that is plugged in or not? I've tried both and doesn't seem to, but maybe I'm doing something else wrong, the idle speed motor doesn't do anything on my B2 other than was slid too far forward causing the throttle to stick partially open so I just slide it down completely out of the way, or is this part of the problem why it will idle so low then I adjust for the low idle with the 2 screws on the front of the carb and cause it to idle too high when its warm?

 

[wildbill23c]

Is there a way to adjust this with that sensor on the air filter housing missing? I've had the same issue with 2 different carbs. I adjust it, and it is ok, then after I drive it for about 10-20 miles it is idling way too high, but if I turn the idle back down then the next day it doesn't want to start. Seems like there is something that I'm missing or not doing right. I started with the 3-1/2 turns out, then went from there on a warm engine, after a long drive its idling high again, the idle motor is inop as is most of the other sensors on the vehicle, and it won't idle worth crap with either carburetor, its like its always revving up or trying to die no matter what the settings are. There's like no in between its either too low of an idle and will die or it idles way too high.

There's also a 2 pin plug on the back of the carburetor, does it make a difference if that is plugged in or not? I've tried both and doesn't seem to, but maybe I'm doing something else wrong, the idle speed motor doesn't do anything on my B2 other than was slid too far forward causing the throttle to stick partially open so I just slide it down completely out of the way, or is this part of the problem why it will idle so low then I adjust for the low idle with the 2 screws on the front of the carb and cause it to idle too high when its warm?

 

[RonD]

http://www.therangerstation.com/tech_library/2_8_FuelInjection.html

Just kidding, or maybe not

This is a good look around the 2150 carb
http://tekatlarge.net/Motorcraft-2150-2V-Carburetor-theory-and-operation.php

It sounds like you are having an issue with the automatic choke.
The automatic part means when the engine is cold the choke plate is set closed and idle set higher, as the choke warms up it opens and idle should decrease, in your case it is not.
Lots of things to go wrong in this automatic setup, having a pull out knob on the dash board, manual choke, was way easier, lol.
Make sure you have good voltage on the choke heater.

 

[enginepaul]

It sounds like you are using the stock system with the computer. The computer controls the idle by way of the idle speed motor and needs the sensors to work properly.
Go to the tech section and pull the codes and go from there.
Please don't buy parts until after you determine the cause of the problem.

That two pin thing in the back of the carb is a lean-out valve that kicks in when you are cruising.

 

[wildbill23c]

Well the choke is non-existant period, the choke plate is tied open as the electric choke was garbage and a huge fuel waste. The idle speed motor is unplugged as the computer is a POS so that has not even been working I'm not sure if the computer functions at all at this point as the computer relay has been sitting on my desk for a couple months now because of some failure in it that was causing an ignition problem which would give me 40mph at full throttle top speed, cured that by removing the relay.

Cause of the problem: Ford designed a pile of shit carburetor/computer system that never was meant to be installed together.

Took it out today after I replaced the starter solenoid, and its running much better after a few more carburetor adjustments and running some seafoam through it. Eventually I'm looking at doing away with whatever is left of the computer, but right now time and money put a damper on any possibility of doing anything to it.