'92 F150, 5.0, XLT wants to die when stopping at red light

[73F100Shortbed]

The valve usually comes with a new gasket. At least the ones I've installed.

 

[Ridgerunner]

I sprayed carb cleaner in it. It still looks dirty.

Does the metal rod inside have to move up and down?
I am assuming when the coil is energized, it field is pulling up on the shaft opening something?

Is my coil measurement shown in previous post in the range?

Is there a way to test this and make sure the moving part(s) are actually moving?

I found a replacement valve but no gasket. I am thinking I can make my own.
What material is recommended?

Sorry for all of the questions but I just want to get this right.

Just use gasket material to make a new one they are basically thin pressed cardboard. If you buy a new IAC it should have a gasket included.

 

[OldFordFart]

I want to thank all of you for helping me out with this issue. The iac is so carboned up, lightly scraping off the build up is just not going to cut it. I'm going with a new one and the cardboard gasket material. I did find some info on testing/troubleshooting this valve on other sites. Here's one way to check this valve out that I found repeated on the web. Hope it helps others out there to understand the how, why, and what if issues they may have.

"How Does an Idle Air Control Valve Work? (IAC)
Introduction
An IAC (idle air control) motor is designed to adjust the engine idle RPM speed by opening and closing an air bypass passage inside the throttle body. The cars computer or ECM (electronic control module) receives information from various sensors and will output signals to adjust the IAC motor in or out to adjust engine idle speed by controlling engine idle air. An IAC motor can fail one of two ways, either the motor short circuits and stops working or the motor will develop high resistance and cause the IAC control motor to react slowly, either failure can cause the engine to stall at idle. When a trouble code scan is performed it sometimes won't always detect a failed or weak IAC motor. To check the IAC motor remove the unit, with the wires connected turn the key to the "on" position without starting the engine, the IAC should move in or out. If the IAC motor does nothing it has probably failed, replace it with a new unit and recheck system. Note: while the IAC motor is removed clean (use aerosol carburetor cleaner) the passages the IAC uses to control idle air speed, also inspect the IAC for a build-up on the seating (pointed) end and clean as necessary.

Idle Air Control Valve (appearance will vary)
________________________________________
________________________________________
Common Problems
An IAC motor is highly susceptible to carbon and coking build up; if an IAC goes too long without cleaning it can cause stalling and poor idle quality. Some cars are designed with a large vacuum transfer hose that connects the intake manifold to the IAC (idle air control) motor. If a broken or dilapidated these vacuum lines can cause the engine to lose vacuum which will allow the engine to run rough and die. Inspect all engine and accessory vacuum lines to look for missing, torn or dilapidated lines and replace as needed. Any car that is designed with a magnetic non-motor operated IAC like Toyota/Lexus is subject to carbon and should be cleaned about every 40,000 miles to avoid stalling.

Basic Maintenance
To check the IAC motor remove the unit, with the wires connected turn the key to the "on" position without starting the engine, the IAC should move in or out. If the IAC motor does nothing it has probably failed, replace it with a new unit and recheck system. Note: while the IAC motor is removed clean (use aerosol carburetor cleaner) the passages the IAC uses to control idle air speed, also inspect the IAC for a build-up on the seating (pointed) end and clean as necessary. "

Thanks again to all who replied to my request for help!

Bear

 

[OldFordFart]

I changed out the aic and it seemed to help. Still not good enough. This morning I changed out the throttle position sensor. This really seemed to help much better with idle. Now I have an issue when I punch the gas, truck pits and putters. Engine light comes on and tack goes down to about 1k, I let up on the gas and all seems ok again, engine light goes out. Punch it again and it pits and putters same way.

Could I have installed the throttle position sensor incorrectly?

Is it something else now?

 

[OldFordFart]

I changed out the aic and it seemed to help. Still not good enough. This morning I changed out the throttle position sensor. This really seemed to help much better with idle. Now I have an issue when I punch the gas, truck pits and putters. Engine light comes on and tack goes down to about 1k, I let up on the gas and all seems ok again, engine light goes out. Punch it again and it pits and putters same way.

Could I have installed the throttle position sensor incorrectly?

Is it something else now?

Anyone out there?

 

[Ridgerunner]

I changed out the aic and it seemed to help. Still not good enough. This morning I changed out the throttle position sensor. This really seemed to help much better with idle. Now I have an issue when I punch the gas, truck pits and putters. Engine light comes on and tack goes down to about 1k, I let up on the gas and all seems ok again, engine light goes out. Punch it again and it pits and putters same way.

Could I have installed the throttle position sensor incorrectly?

Is it something else now?

I don't know about the TPS, but try a new fuel filter and injection cleaner. If you need injectors look on Ebay for a rebuild kit cost about $25.00 but try the other first.

 

[OldFordFart]

I didn't have a problem with truck spitting and sputtering before I installed the throttle postion sensor. It never really took off when I punched it, but did downshift and not sputter. Am I supposed to do something else after installing it?

For the injector cleaner, I'm hearing Seafoam is a good one for my old truck. I've never heard of it. What do you say?

 

[73F100Shortbed]

Did the tps have slotted holes for adjustment? You could unplug it and see how it reacts to that. Hopefully you didn't get stuck with a defective part. If this only showed up after installing it I would check that over before worrying about injectors or anything like that. I haven't messed with a tps on one of these trucks in quite some time so I can't remember all of the specifics for testing them.

 

[Justin]

Your TPS is adjustable. Take a look at any repair manual and break out your multimeter. There are resistance specs that it should match up too.

And to be honest, most of the parts store TPS units are ****. I've gotten bad ones out of the box a few times.

If you really have a TPS problem, I'd cruise rockauto and see if you can find a motorcraft sensor.

 

[Ridgerunner]

I didn't have a problem with truck spitting and sputtering before I installed the throttle postion sensor. It never really took off when I punched it, but did downshift and not sputter. Am I supposed to do something else after installing it?

For the injector cleaner, I'm hearing Seafoam is a good one for my old truck. I've never heard of it. What do you say?

Seafoam is all I use. Also if you follow the directions it can help remove carbon from your valves.

 

[Justin]

Also, do you have any codes?

 

[OldFordFart]

Also, do you have any codes?

Don't know of any codes. I do not have a device that reads 'em. I tried the paperclip method I read about. I just don't understand this way of reading codes.

 

[Justin]

You count the blinks of the CEL.

So 23 would be:

blink/pause/blink/pause/pause/pause/blink/pause/blink/pause/blink