Iac?

[kensmith69]

Can anyone tell me where the IAC is on a 2000 GM 1 ton with a 454?

 

The truck is backfiring badly , so badly its hardly drivable.

Its got lots of power and runs and idles great but when you let off it almost blows the box off?

Someone told me to clean the IAC?

Any other ideas?

[kensmith69]

Can anyone tell me where the IAC is on a 2000 GM 1 ton with a 454?

 

The truck is backfiring badly , so badly its hardly drivable.

Its got lots of power and runs and idles great but when you let off it almost blows the box off?

Someone told me to clean the IAC?

Any other ideas?

 

 

Did i post this in the right place?

I cant believe no one has any thoughts on the cause of my problems?

[txab]

Have you pulled the diagnostic codes?

[pwall]

http://www.ehow.com/how_5883650_clean-gm-iac-valve.html

 

Welcome btw! ;)

[twavor]

I may be wrong, but I think you're barking up the wrong tree...it's a pain in the butt, but I'd be checking for a very badly leaking fuel pressure regulator. Does this start hard/crank a little while before it starts, especially hot?

The IAC is on the throttle body...been awhile since I had a 7.4 here, but take the plastic cover off the top of it(two 13mm nuts) and it makes things easier. Don't push or pull the pintle on the IAC either, just spray some good carb cleaner on and in things and don't get wild with a wire brush. I normally just use the air nozzle after I let it soak a little, maybe wipe it off with a rag, but I'd be surprised if you find alot of carbon on it, it'll be black, but not mounds of carbon.

 

Travis

[kensmith69]

I may be wrong, but I think you're barking up the wrong tree...it's a pain in the butt, but I'd be checking for a very badly leaking fuel pressure regulator. Does this start hard/crank a little while before it starts, especially hot?

The IAC is on the throttle body...been awhile since I had a 7.4 here, but take the plastic cover off the top of it(two 13mm nuts) and it makes things easier. Don't push or pull the pintle on the IAC either, just spray some good carb cleaner on and in things and don't get wild with a wire brush. I normally just use the air nozzle after I let it soak a little, maybe wipe it off with a rag, but I'd be surprised if you find alot of carbon on it, it'll be black, but not mounds of carbon.

 

Travis

 

 

Thanks guys.

Travis , yes it is hard to start.

It sounds like a dodge rrrr rrrr rrrrr rrrr rrr rrrr then starts!

 

Where is the fuel regulator.

Thanks ken

[twavor]

Thanks guys.

Travis , yes it is hard to start.

It sounds like a dodge rrrr rrrr rrrrr rrrr rrr rrrr then starts!

 

Where is the fuel regulator.

Thanks ken

The fuel pressure regulator is clear back behind the upper intake plenum, back by the distributor. Basically all you gotta do is pop the short vacuum line off of it and see if any fuel comes out of the hose or regulator...lot's easier said than done, and lots easier if you take the upper intake off to do it. You may want to have someone who's done it before check it out for you. If the regulator is leaking, you are putting lots of gas in the engine that don't need to be there.

 

Travis