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  • September 30, 2022, 01:11:38 PM

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Author Topic: How to tell if pulse air check valves are working?  (Read 133 times)

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Offline Artmodels

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How to tell if pulse air check valves are working?
« on: July 20, 2022, 11:52:56 PM »
Just a quick question, hopefully someone knows the answer.

I tested the pulse air vacuum lines on my 83 eagle.  When the car is running, and I direct connected the vacuum pulse line to actuate it, I heard the louder noise of the pulses on the forward injector line, but rear did not change noise noticeably.  One thing I DID notice however, is that with the vacuum lines energized, I could feel the pulses by putting my fingers into the two 3/4" holes in the rear of the air cleaner housing.

This is where I thinl my worry is starting, because both holes soon started pulsing very very HOT!  I thought that the pulse was supposed to suck air from the air cleaner, not end up moving the hot (exhaust?) air into the air cleaner.

Does this mean the one way valves in the lines are not working?  I noticed this was while at engine idle speeds. Could this affect the engine emissions being dirtier, due to an overabundance of !hat is basically a lot more egr type exhaust gasses entering air  cleaner.

Any advice is appreciated! Thanks!

Online MIPS

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Re: How to tell if pulse air check valves are working?
« Reply #1 on: July 21, 2022, 01:44:50 AM »
The check valve should only allow fresh air into the exhaust and no exhaust back up and into the air cleaner. A monometer or vacuum gauge should see a small amount of vacuum on either port in the air cleaner.

Yes a bad check valve will cause soot and exhaust gases to come back up and into the carb, fouling it and acting like the really early fixed orifice EGR's. I'm not sure if the check valves are still available or if the regular air injection check valves will work in their place.
« Last Edit: July 21, 2022, 01:46:19 AM by MIPS »

Offline Artmodels

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Re: How to tell if pulse air check valves are working?
« Reply #2 on: July 21, 2022, 10:34:31 AM »
Yes thats what I thought.  I will need to find those valves, but in the meantime, will it hurt the emissions if I plug the two air cleaner holes with a rubber plug?  I think that might help with engine power and performance, to not have a significant portion of its intake air diluted with oxygen void exhaust.

Online MIPS

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Re: How to tell if pulse air check valves are working?
« Reply #3 on: July 21, 2022, 11:32:21 AM »
*I think* Air tube catalytic converters will overheat if you block off their air supply.....or was that if their control valve sticks open.... Either way, If one of the check valves is leaking less than the other, switch them around so you can at least keep the downstream supply working and block off the other until you can get a replacement.
« Last Edit: July 21, 2022, 11:36:01 AM by MIPS »

Offline Artmodels

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Re: How to tell if pulse air check valves are working?
« Reply #4 on: July 21, 2022, 12:53:13 PM »
I found it is bad,   bought a replacemnt from carquest, it is model number cvc 1001, and looks a little smaller than whats on there. Carquest computer says will fit 83, but also says it fits air pump version.  Anyone know if this is accurate?

Online MIPS

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Re: How to tell if pulse air check valves are working?
« Reply #5 on: July 21, 2022, 02:11:00 PM »
Exhaust Part Catalog lists the check valve for Pulse Air (six cylinder) to be 8933000354. Google cross reference lists this as compatible with the Dorman 355050. Their website also lists it as a compatible part. - https://www.dormanproducts.com/p-5862-355050.aspx

If you don't like Dorman's build quality, anything listed as compatible with the 355050 should work.

Offline Artmodels

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Re: How to tell if pulse air check valves are working?
« Reply #6 on: July 21, 2022, 03:10:09 PM »
Thank you very much!

 

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