Has anybody here removed/plugged the IAC?

[superdave]

An IAC valve is like $20. Why would you try to work around a bad one?

 

[someotherguy]

You have a lot of experience with this (or similar) stuff. Thanks for the info. I can now set my idle at whatever rpm i'd like in about 30 seconds with a screwdriver. If it won't idle in the winter when cold, I will just run the idle up higher for the winter.

It's engine temp you're concerned with, not ambient. If you adjust for good idle when cold, once the engine warms up it will idle too fast.

Not sure why the hostility towards some of the others in this thread but I guess you seem dead set on doing whatever it is you wanna do, not sure why it needed a discussion then..

Richard

 

[letitsnow]

It's engine temp you're concerned with, not ambient. If you adjust for good idle when cold, once the engine warms up it will idle too fast.

Not sure why the hostility towards some of the others in this thread but I guess you seem dead set on doing whatever it is you wanna do, not sure why it needed a discussion then..

Richard

I wasn't looking for opinions on why I shouldn't do it - I was asking if anybody had done it. People seem to get a bit weird on here if anybody wants to try something that isn't 'by the book'.

 

[letitsnow]

An IAC valve is like $20. Why would you try to work around a bad one?

Because its job irritates me, and I think that it's wrong, like I had already typed.

 

[letitsnow]

Reminds me of folks who don't understand how an automatic choke works, won't take the time to learn, and make improper adjustments that make the original problem worse.

Then instead of doing proper diagnosis and learning about the system they're working on, they cobble a cable linkage and brag about how expertly they can control a manual choke.

Some folks need their fingers broken with their own wrenches.

That funny, coming from somebody who was too lazy to google 4l80e lockup haha. I use my truck for winter and summer camping. I need tire chains to pull the camper through some of the snow. Sometimes it is below zero, sometimes it is 90 degrees out. I assure you - nothing on my truck is cobbled together. Everything that I have done, I have done for a reason. I could buy a new diesel 1 ton tomorrow if I wanted to. I don't.

 

[letitsnow]

I grew up on carb'd trucks, just because that's how they came from the factory. Of course, they were all old neglected POSs. Imagine my surprise when I finally plunk down the cash on a fancy new Edelbrock 600cfm 4bbl carb and the instructions describe, in great detail, how to set up the automatic choke. That was hands down the best running carb'd car I've ever known (minus hot restarts, vapor lock, and power left on the table to a Holley). Only when the temps dropped below zero did it require more than one simple pump to set the (adjustable!) high idle. So many people love carbs and yet so few of those people know WTF they're actually doing with them.

I once put a new Edelbrock on a K5 Blazer. That truck ended up running really well. I put a 6" lift and 33's on the K5. That truck got the same mpg (or better) as every efi truck that i've owned since.

 

[Schurkey]

I once put a new Edelbrock on a K5 Blazer. That truck ended up running really well. I put a 6" lift and 33's on the K5. That truck got the same mpg (or better) as every efi truck that i've owned since.

I would hope so. But the manufacturer isn't allowed to sacrifice emission control for MPG.

A carb can be tuned to provide 15- or 16-to-one air fuel ratio at cruise. Anything that has to meet emissions regulations is going to be locked into approx. 14.7-to-one everywhere except heavy throttle, and then it's even more rich.

So you're no hero because you can achieve decent driveability and fuel economy. When you can do better than GM engineers while meeting full EPA regulations, you'll get some respect.




In your defense, you've had several folks say you should just drop another IAC on the unit. Those folks need to understand that that won't help if you have a defective wire harness, or faulty IAC circuitry in the ECM. IAC problems don't have to be a faulty IAC. The whole IAC system has to be examined. THEN there's the concept that even a properly-functioning IAC won't be able to provide a proper idle if there's mechanical problems within the engine--for example, lack of compression on a couple of cylinders, or other electronic issues such as faulty spark-advance circuitry, that sort of thing. Not only does your "faulty IAC" not have to be a faulty IAC, it doesn't even have to be within the IAC system.

We already know there's throttle-body problems because of the sticking throttle shaft.

The only way to know what it is is to learn what you're working on, and do diagnostic testing.

That funny, coming from somebody who was too lazy to google 4l80e lockup haha.

At least I'm trying to learn about what I'm working on. I didn't ask for help to install a Turbo 400 in place of the 4L80E because the '80E has a malfunctioning TCC that ****** me off, and a 400 doesn't.

 

[letitsnow]

I would hope so. But the manufacturer isn't allowed to sacrifice emission control for MPG.

A carb can be tuned to provide 15- or 16-to-one air fuel ratio at cruise. Anything that has to meet emissions regulations is going to be locked into approx. 14.7-to-one everywhere except heavy throttle, and then it's even more rich.

So you're no hero because you can achieve decent driveability and fuel economy. When you can do better than GM engineers while meeting full EPA regulations, you'll get some respect.




In your defense, you've had several folks say you should just drop another IAC on the unit. Those folks need to understand that that won't help if you have a defective wire harness, or faulty IAC circuitry in the ECM. IAC problems don't have to be a faulty IAC. The whole IAC system has to be examined. THEN there's the concept that even a properly-functioning IAC won't be able to provide a proper idle if there's mechanical problems within the engine--for example, lack of compression on a couple of cylinders, or other electronic issues such as faulty spark-advance circuitry, that sort of thing. Not only does your "faulty IAC" not have to be a faulty IAC, it doesn't even have to be within the IAC system.

We already know there's throttle-body problems because of the sticking throttle shaft.

The only way to know what it is is to learn what you're working on, and do diagnostic testing.


At least I'm trying to learn about what I'm working on. I didn't ask for help to install a Turbo 400 in place of the 4L80E because the '80E has a malfunctioning TCC that ****** me off, and a 400 doesn't.

Enjoy your moms basement. You can hang out down there and dream about "breaking peoples fingers with their own wrenches". I'm guessing in real life, you get your ass handed to you regularly.

 

[letitsnow]

When I started the truck this morning it was around 15 degrees F. It started fine and idled at about 600 rpms on the factory tach. I used the truck for a few hours and it idled nicely at 750-800 rpms once warmed up. So far so good.

 

[wheelman]

You people made me laugh.my uncle was a fine mechanic.one thing he all ways said about all vehicles..was keep

It stock.keep it stock.i say.go back to ol school vehicle.or go new some people love carb vehicles.some like fuel injection vehicles.

Just go with one or the other.i like both.but I'm not going to play with or screw up a fuel injection system

Just to be able to turn a screw.thats not supposed to be touched.a lot of guys end up wrenching

Instead of riding.