Air Leak from Warm Up Regulator. How Much Is Ok?

[PaulTWinterton]

I'm chasing a lean condition, lumpy idle, minor bucking, and no high idle during warm up.  Trust me when I say I've been through all the systems and have little else to trouble-shoot and make right.  If my following question doesn't lead to a solution I will post ALL my settings and engine details.

 

Question: does a properly operating WUR allow any air into the log once the piston is elevated fully to the 10mm height?

 

With my engine at operating temp I pinched the air hose (fully sealed) on the back of the WUR.  Here's what happened.

 

RPM at idle: 950,  RPM at idle with pinched WUR air hose: 850.   A drop of 100rpm.    No telling what impact that air flow would have at higher engine speeds.

 

Super-long needle nose pliers.

 

There's nobody in my neighborhood that knows the WUR intimately.  I'm hoping someone here can tell me if my WUR is or is not doing it's job.

Thanks for reading and replying.

 

 

 

[Einspritz]

OK, first you said that there is no high idle, but it is at 950 rpm, slowing to 850 when you pinch the hose. I ALWAYS set the idle at 850 rpm, so I think the hose MAY be suspect. It should be rock steady. Regardless of what you set it at, the idle should not change when you pinch the hose. Might it  be cracked at the warm up regulator or the clamp allowing air to pass?

 

Second, yes the warm up regulator should seal completely.

The wax "motor" (yes that is what the manufacturer calls it) may not be fully extending upon warm up. Also, these take maybe 15 minutes to fully extend...they are not quick, but you already know that.

 

You mention a lumpy idle, a sure sign of false air somewhere......what is the condition of the rubber cap on the underside of the throttle body? Are there seals on the butterfly bearings?

 

Third, a lean running condition, could be caused by the false air, but at what rpm is it lean? How do you measure the mixture, lambda, CO at the tail pipe?

 

At full throttle, the small amount of false air has negligible effect.

[PaulTWinterton]

1 hour ago, Einspritz said:

the warm up regulator should seal completely.

 

That's the answer I was looking for.  Thanks.  

 

You have to understand that I've been over every inch of my motor.  Every seal, hose, clamp, nut, bolt, linkage, wires, plugs, yada yada yada, a hundred times.  Everything is as is should be.  My symptoms scream vacuum leak and this was the last place air could be getting into the system.

 

So...up to this point I've been trying to tune my injection with false air in the system.  All your points are valid but without removing the vacuum leak NONE of my AFR readings or tuna can/intermediate shaft settings are worth talking about.   Once I have an airtight system I can readjust everything and hopefully have a healthy engine. 

 

Now I have to remedy the WUR.  It extends the full 10mm, but still leaks.  I may need a replacement.  I foresee removing it in the next few days and doing an autopsy.  

 

For now I'll just drive at full throttle.  AFR reads 13.9 with my foot to the floor.  Just kidding.

[Einspritz]

After removing it, try blowing through to confirm, and check that the internal parts seal. While you are in there,  it might be a good thing to check the O Ring to make sure that you don't have a future water leak causing corrosion.

 

I have never measured the wax motor, but similar were also used in the oil cooler valves in the Turbo and E30 engines, perhaps others. If you can't find one, I may be able to help.

 

Keep us apprised.

[Son of Marty]

Also when you take it apart check to see if the water jacket around the wax motor is clear of crud it can prevent the air bypass from closing completely worth a look anyway.

[jgerock]

I removed the WU regulator from my spare 72tii KF pump but cannot figure out how to take it apart.

 

The coolant inlet section has lots of corrosion, so I have sprayed Liquid Wrench in the (3) tubes and down the top section.

 

I tried using a set of snap ring pliers to turn the inner section but it won't move.

[Einspritz]

some of the corrosion can be removed by dipping in CLR.