BIZARRE end to the hunting/stumbling idle issue on my ‘95.

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L31MaxExpress

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If they are already junk, agreed, but if you keep them clean they’ll last longer. It is a maintenance part.
Cleaning them does not change how quickly the diaghram fails and put the wrong chemical in to contact with the diaghram and it will probably eat it on the spot.
 

L31MaxExpress

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Also for those that want to know, AC Delco sells like 3 tiers of parts as well. From about the same quality as you would find from the local Autozone's Valucraft offerings up to the OEM part that was produced for your vehicle.
 

Caman96

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Cleaning them does not change how quickly the diaghram fails and put the wrong chemical in to contact with the diaghram and it will probably eat it on the spot.
If you put the wrong chemical in your fuel tank you’d have problems too. I use Berryman’s to clean it. Manual says to service it at 60k.
 
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L31MaxExpress

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The problem with the AC Delco and most aftermarket EGR valves is in the vacuum fitting itself. The OEM valves have a tiny, metered orifice that slows the EGR opening, where the AC Delco and aftermarket units typically have a wide open vacuum port. I have run across the same issue with vacuum operated choke pull-offs, especially Q-Jet ones. Without the tiny metered orifice they do not function as designed. A bad pull-off is why the Quadrajets are typically known as a Quadrabog.
 

98 Nitro

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Ac Delco has:
An OEM line, the Professional/Gold line, and the Silver/Advantage line which vary in quality and often you can not get OEM.
Perhaps the mechanic had a used or NOS part with the OEM part number and fixed it.
 

Caman96

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I see GM Genuine parts and when they’re listed that way it’s always the higher price than Acdelco Gold/Professional. Go to the Acdelco.com site, it shows they are the exact same part. I check that all the time and it always shows that. So, if I can’t find a NOS part, which I always look for I will get it as Acdelco Gold/Professional at a cheaper price. Same part.
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I’ve also called Acdelco about this and they confirm they are the same parts.
 

Caman96

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The $260 was JUST the part. His total bill was about $650.00.
Ouch!! I took mine off a couple weeks ago, 2 bolts right up front on engine. If I was just installing a new one it’s a 15 minute job at an easy pace.
 

someotherguy

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The $260 was JUST the part. His total bill was about $650.00.
Not a single EGR valve I see listed for the application costs more than $67 and that inlcudes "GM Genuine (not AC Delco)" ...

$650? What all was done? Your friend took the truck to a guy that said he was an old GM mechanic and knew he could fix it, replaces the EGR that it sounds like he grossly overcharged for, and charged $390 more for.. what? No wonder the mechanic wants to keep it a secret. He's winning..

BTW for most Fed emissions TBI 5.7's the EGR that worked for me on more than a few was the Delphi EG10099 (currently $57) but that doesn't mean it works for every application.

Richard
 
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