Idle air tube to air mixture question.

[Beachdrifter]

Hi all. I'm concerned that the tube that goes from the idle control valve to the bottom or mixture unit is not making a good seal. I can easily pull the tube out and it seems really loose. It feels like the tube is just rubbing metal to metal in hole.

Question , would an air leak or improper seal in this area prevent the car from idling at all or cause the car to idle rough with severe hesitation ? Probably something like if the co mixture screw plug is left out?

Thanks for any insight.

~Randy

[Bitsyncmaster]

It will feel loose if the tube has been greased as recomended. You can look for leaks in the dark with a flashlight aimed down where the tube ends and look into the mixture unit while pressing the flap (round aluminum plate) down.

[David T]

It will feel loose if the tube has been greased as recomended. You can look for leaks in the dark with a flashlight aimed down where the tube ends and look into the mixture unit while pressing the flap (round aluminum plate) down.

There is supposed to be a brass cup holding an "O" ring in place to seal the tube to the mixture unit. Difficult to see if the "O" ring is there without removing the mixture unit.

[OverlandMan]

Is this the "pipe of agony"?

[David T]

Is this the "pipe of agony"?

For some people, Yes. It can be difficult to get the pipe inserted.

[OverlandMan]

For some people, Yes. It can be difficult to get the pipe inserted.

The little kid in me wanted so badly to reply: "That's what she said"...

But the adult in me is more interested in getting this pipe reinstalled soon on my car and based off the fact that it's unofficially labeled "the pipe of agony", I'm already timid about getting it reinstalled correctly.

I'm also looking at replacing the ISM. I've looked up the Bosch part number and checked around. What are other folks doing for replacements? Mine was damaged in my engine fire. I haven't tested it yet but it does have external damage and seems to have gotten hot with the flame right underneath it.

[Jacko]

I recall someone on this forum permanently welding the pipe to the mixture unit.
I wonder how that turned out. :confused0:

[Bitsyncmaster]

Installing the pipe is not the problem. It's if that brass cup falls out, then you have to pull the mixture unit out to put it back in.

[DMCMW Dave]

Installing the pipe is not the problem. It's if that brass cup falls out, then you have to pull the mixture unit out to put it back in.

Later versions of the engine had the brass tube cut much shorter and press-fit into the metering assembly. The curved rubber hose from the idle motor was much longer.

Not sure where you'd find the hose (Volvo?), but in theory this modification could be done with some epoxy.