This is my first posted questionon this board and it's finally in the right place (YEAH!)

BACKGROUND: I have a 1988 Chevrolet s-10 tahoe blazer (6 cyl) 2.8< trying to smog it. It is close to passing smog but has a NOX problem. I have replaced many things I'm sure have helped and replacing them even if they work isn't a problem (Just helps) The major problem seems to be throttle body injectors but since they are very expensive I wanted to get an opinion from many of you first.

MAIN QUESTION:
There is a GLUG GLUG at low RPM (this is where it hasfailed smog last with high NOX) and the fuel is coming out of the injectors but with a hesitation (sprinkler like) is this normal or is it my culprit? PS I have adjusted the valve lash thouroughlyand gas pump was fixed at an ASE shop + New Computer before last smog. I have since replaced theOxy Sensor &fuel filter but still has a glug glug glug. Please Help (I have until end of april to fix this thing)

 

First off, welcome! Second, thanks for creating a new thread. It helps to avoid confusion and keep the other thread on track to help the original poster get his problem fixed.

On to your problem. Droplets of fuel are not good. The injectors should be able to atomize the fuel in a consistent spray regardless of the RPM. I would start with a heavy dose of fuel injector cleaner to see if the problem is just dirty injectors. To break up the varnish that may be plugging up your injectors as quickly as possible, try using 2 'treats 18 gallons' bottles of Chevron Techron Concentrate Plus.

If that doesn't do the trick, you may have to replace the injectors, but I would verify proper fuel pressure before doing that.

 

That is what I thought. But it isn't droplets it is spraying, just spraying with a hesitation like pulsing out like the glug glug sound. There is actually no loss of power and fuel flow is good to from the fuel filter. what about taking the injectors off and carb cleaning them? Or maybe an acid bath?

 

Where is the glug glug sound you speak of coming from? The injectors themselves? The injectors should be pulsing, not continuously spraying, but I don't understand what you mean by a glug glug sound... Is it like when you are pouring soda out of a 2 liter bottle or what?

I would not acid clean the injectors, you risk destroying the seals. A stiff concentration of fuel system cleaner through the tank should clean them up if they are only dirty.

 

The Glug Glug is from the engine itself and is heard from the exhaust. It's a sound like a motorboat or harley bike.

More like a GUGGUGUGUGUGUGUGUGUGUGUGUG while at idle but goes away with higher RPM's

 

have u checked ur exhaust for leaks (holes or rusted thru spots)? this could cause the GUGUGUG.... sound u r speaking of

 

I'm not sure about the GUGUGUGUG sound, but I thought that NOX is controlled by the EGR valve. Have you checked the EGR operation or removed it to see if the passage is not plugged with carbon?
To check EGR operation I usually try to lift the diaphram with the engine idling, if it's working the idle will drop and usually the engine will stall.

 

My 2 cents are that while idling it maybe be getting to much fuel and the gug sound might be the engine trying to sputter? Its this correct or no? If at a Idle the injectors are spaying and not pulse with a fine mist, then it sounds like the injectors are gone. try this while idleing and its doing the glug glug thing take a pair vise grips and just pinch the rubber fuel line a little and see if it help. But Im not sure if Im not there kind of deal. Hope everything works out for ya.

 

I am going to try to aswer all the questions in one statement:
I have copletely checked the EGR and the EGR Silonoid and they are working.
I have had the muffler guys replace and weld a new catyltic converter It is welded very good but I will do another full visual check of the exhaust manifold.
I will also try slowing the fuel flow while at idle.
I will also try fully cleaning the injectors (when Iobtain the star tool required to remove them)

Thank you all for your input I will attempt all of these and I will report any results here.
Hopefully I can find the problem.

You are all being very helpful (I thought I was out of options) I guess I haven't tried everything.

 

the star tool u speak of is a temper proof torque. and if u still rnt able to diagnose it a short video or sound clip would help too if u can