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View Full Version : General idle speed motor auxiliary air pipe



glockworks21
01-23-2023, 06:43 PM
how is that air pipe connected? i am replacing ism and noticed that the pipe is loose and bouncing around under intake.


Thanks
Dave

Michael
01-23-2023, 08:18 PM
how is that air pipe connected? i am replacing ism and noticed that the pipe is loose and bouncing around under intake.


Thanks
Dave

It's a loose fit, no real seal under the metering plate. You can manually open the metering plate and see if it is indeed seated properly.

Ron
01-23-2023, 09:00 PM
It goes into a port in the side of the intake manifold that has an o-ring and its retainer. A loose/slip fit.

glockworks21
01-23-2023, 09:50 PM
thank you both!!


Dave

Rich
01-23-2023, 10:04 PM
Yes on all of the above.

You're reinstalling the Auxiliary Air Pipe, a.k.a. The Pipe of Agony.

Refer to this thread (https://dmctalk.org/showthread.php?3466) for more fun details about it.

It's Item 21 in this diagram (https://store.delorean.com/parts/fuel-emissions/2-5-0-idle-speed-motor-ecu-microswitch.html). The brass-rubber seal it slides through on the intake manifold isn't shown. The vendors will sell you one if you lost yours.

The fact that your POA rattles around means it's not inserted in its hole at all or the seal is missing. Either way the engine won't idle well.

Looking down past the round air meter plate will tell you if the pipe is through its hole, as Michael says.

Looking toward the hole from the outside with a mirror or borescope (with pipe out) will tell you whether the seal is held in place.

glockworks21
01-23-2023, 10:25 PM
Yes on all of the above.

You're reinstalling the Auxiliary Air Pipe, a.k.a. The Pipe of Agony.

Refer to this thread (https://dmctalk.org/showthread.php?3466) for more fun details about it.

It's Item 21 in this diagram (https://store.delorean.com/parts/fuel-emissions/2-5-0-idle-speed-motor-ecu-microswitch.html). The brass-rubber seal it slides through on the intake manifold isn't shown. The vendors will sell you one if you lost yours.

The fact that your POA rattles around means it's not inserted in its hole at all or the seal is missing. Either way the engine won't idle well.

Looking down past the round air meter plate will tell you if the pipe is through its hole, as Michael says.

Looking toward the hole from the outside with a mirror or borescope (with pipe out) will tell you whether the seal is held in place.



Wow this looks fun. Thanks for the link. glad i took the weekend off. Im guessing with as much play that it has in all directions and the metal on metal sound that its not inserted at all...

glockworks21
01-23-2023, 10:53 PM
well it was going to be a weekend project but i got impatient.
The metal washer and o ring are there. the pipe was inserted but o ring and metal sleeve were not close enough to make seal. (maybe cause i was moving it around) I will try to use locktite or some kind of sealer to hold the metal ring in place. I dont want to remove the mixture unit.

thanks again.

DaraSue
01-24-2023, 12:36 AM
well it was going to be a weekend project but i got impatient.
The metal washer and o ring are there. the pipe was inserted but o ring and metal sleeve were not close enough to make seal. (maybe cause i was moving it around) I will try to use locktite or some kind of sealer to hold the metal ring in place. I dont want to remove the mixture unit.

thanks again.

Whatever you use, make sure it's something removable so you're not cementing the pipe in place in case you need to take the intake off again. A buddy of mine suggested Hylomar (the kind they use on Harleys) but I've never tried it myself.

MrChocky
01-24-2023, 07:44 AM
well it was going to be a weekend project but i got impatient.
The metal washer and o ring are there. the pipe was inserted but o ring and metal sleeve were not close enough to make seal. (maybe cause i was moving it around) I will try to use locktite or some kind of sealer to hold the metal ring in place. I dont want to remove the mixture unit.

thanks again.

With gentle use of a mallet, the ring can be tapped slightly out of shape and then tapped into the intake, and should hold no problems.

glockworks21
02-08-2023, 09:19 PM
With gentle use of a mallet, the ring can be tapped slightly out of shape and then tapped into the intake, and should hold no problems.

I struggled with it enough. I could never get the ring to stay in place. If i did it would easily get knocked out when trying to connect hoses.
I ended up putting a hose clamp on the pipe in front of the brass ring to keep it from sliding back. then I put on a new o ring and a small amount of clear silicone.
I was able to push it in snug and let it dry. I know its not right but it worked. May save someone hours in the future...

Thanks all,

Dave

iflights
02-09-2023, 08:44 AM
I struggled with it enough. I could never get the ring to stay in place. If i did it would easily get knocked out when trying to connect hoses.
I ended up putting a hose clamp on the pipe in front of the brass ring to keep it from sliding back. then I put on a new o ring and a small amount of clear silicone.
I was able to push it in snug and let it dry. I know its not right but it worked. May save someone hours in the future...

Thanks all,

Dave

A true pipe of agony moment.

MrChocky
02-09-2023, 10:12 AM
I struggled with it enough. I could never get the ring to stay in place. If i did it would easily get knocked out when trying to connect hoses.
I ended up putting a hose clamp on the pipe in front of the brass ring to keep it from sliding back. then I put on a new o ring and a small amount of clear silicone.
I was able to push it in snug and let it dry. I know its not right but it worked. May save someone hours in the future...

Thanks all,

Dave

It's a pretty odd design. Honestly if what you did is sound, then I'm not going to argue. Others have done much worse.

AugustneverEnds
02-09-2023, 04:13 PM
I struggled with it enough. I could never get the ring to stay in place. If i did it would easily get knocked out when trying to connect hoses.
I ended up putting a hose clamp on the pipe in front of the brass ring to keep it from sliding back. then I put on a new o ring and a small amount of clear silicone.
I was able to push it in snug and let it dry. I know its not right but it worked. May save someone hours in the future...

Thanks all,

Dave

That sounds like a simple, neat, effective way to get that menace in there securely. Nice work MacGyver! :cheers1:

glockworks21
02-10-2023, 03:07 PM
That sounds like a simple, neat, effective way to get that menace in there securely. Nice work MacGyver! :cheers1:

lol thanks

another thought i had for future was to take a piece of rubber 2-4mm thick trace out a hole slightly smaller than the pipe so you can slide it through and have a decent seal.. then silicone it to the intake with the o ring underneath. the rubber seal would act as the brass ring and hold the o ring in place. Then with a little lube you could slide pipe in and out easily and i think it would keep a decent seal. (maybe?) Not sure if there is enough contact area to silicone the rubber on though.. next time i take it out i will try it...

cleaned valley.. new plugs wires fuel lines all gaskets and the pipe hack and its running solid now...
Thanks again for all the help..

Dave

Rich
02-10-2023, 03:22 PM
....cleaned valley.. new plugs wires fuel lines all gaskets and the pipe hack and its running solid now...
Thanks again for all the help..

Dave

Thx for this update.
Nicely done. Great way to start the weekend.

A VOD job is rewarding when it comes out right, as it usually does.