4 replies to this topic

[jimfj]

I need some schooling here. Can you clean or service an EGR valve???

I read this and have most of these symptoms

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  Poor Idle
  
  
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  When an EGR valve fails to open or close properly, it acts as a vacuum leak and alters the fuel-to-air mixture ratio. The result is an fuel-air ratio that ends up being too lean or too rich, causing the engine to misfire and sputter at idle speeds.

Engine Knock

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  Engine knock is caused by the premature ignition of the fuel and air mixture within the combustion chamber. When an EGR valve fails to operate correctly, it can cause the temperature within the combustion chambers to increase, causing the fuel and air mixture to ignite prematurely. The result is knocking and pinging when the engine is placed under load or under acceleration.

Overheating

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  EGR valves reduce the temperature of the combustion process by adding exhaust gases to the fuel and air mixture. When an EGR valve fails to open, not enough exhaust gas is added, causing the combustion temperature to rise, as well as the overall operating temperature of the engine.

I need to qualify that the most prevalent symptom is the knock or rattle as I call it, when under acceleration. It isn't horrible but you can certainly hear it. No knock at idle or cruising at RPM.

The idle will sometimes sputter and miss as well. The car has had a thourough carb clean and every tuneup part replaced including the fuel filters.

So, Can I clean the valve or do I just replace the darn thing. Could it be something else? My HF has stock carb and vac lines and I believe I want to keep it that way for awhile.

[Bubba]

You can take off the EGR valve and clean it- it is a simple device. Also double check your ignition timing and also check that your vacuum advance diaphragm isn't leaking (use a hand held vacuum pump). I think you should also check for vacuum leaks- spray some carb cleaner around the base of the carb and see if the idle smooths out- the rubber carb base gaskets typically begin to crack as they get old.

[jimfj]

Well,

I took off the magic EGR valve. It was carboned up, so scraped the crud off and then shot it with carb cleaner, both the valve itself and the intake. Buttoned everything up and not much change, so thats not really my problem. I have checked all the vacuum lines and replaced some.

I have not checked my timing or my dizzy advance. The little car runs really well but there is still some fine tuning to do. Just looking for that last little bit that makes the motor sound like a very quiet sewing machine. Almost there.

[JcleanDrx1stM]

the egr valve is behind the intake manafold right?

[jimfj]

EGR valve is located in the front of the engine left side right next to the dizzy on my car. Has a vaccum line attached to the side and a black plug clamped to the top. It is a round valve. hope this helps