Last week my 1993 4WD S10 blazer 4.3L V6 FI Vortec vin code W started running very rough and rich at idle. I got a Code 12, 32, and 45, on the ECM and 66 on the ABS (see below)


Ok heres where I'm at. On my Easter Sunday I removed cleaned and reinstalled EGR valve. New plugs, wires, cap, rotor, PCV valve, and dropped a bottle of lucas oil FI cleaner in the tank. Runs like a clock at first after about 20 mins after warming up it starts running rough and smelling rich at and near idle speed. I am still getting code 32 and 45. Can anyone come up with a possibility? I hate not being able to test the EGR as I don't want to blow 200 bucks unless I am positive that that is the problem. Mechanic at work has a theory that the spring inside the EGR is worn and weakening when it gets hot and not allowing the valve to close.

There is a good possibility that I am getting tunnel vision and focusing too much on the EGR, but thats what code 32 is supposed to be. I am guessing thas the 45 code is being caused by the EGR causing the engine to run rich therefore causing an O2 sensor error.

We bought this to teach my wife how to drive after years of not having enough money. She is starting to

[:@] HELP!!!!!!!!!!!!!

 

Update:

Is this as bad as it looks? Should I just replace everything? Injectors included? Any and all input, tips, and freebees to save me $$ would be greatly appreciated!

 

That actually doesn't look to bad under there. Have you pressurized the system with the upper plenum off, looking for leaks? From the pictures, there doesn't appear to be any large scale leaks by the lack of pooled fuel...

About the code 32, I'm wondering if the EGR valve is actually working properly. This code is typically present when the EGR valve does not open enough to produce the required drop in the MAP sensor reading for a given input to the EGR valve.

Code 45 is indicating a problem which is causing a rich condition. The fact that it really causes a problem after the vehicle has warmed up leads me to believe that it is a sensor problem.

 

As you can see by how shiny it is, I pulled the EGR and cleaned it in the parts tank at work. It is new looking inside with no carbon left, I can push the valve in and out with no resistance. Speaking of resistance I ran an ohms check from pins a to e and got 10.1 ohms so the solinoid is not shorted out we hooked it up to a power suply at work and the valve clicked open just fine. The channel the Egr bolts to is a different story it is heavy with carbon. The block is rebiult (according to the guy I bought it from) but all the components with the exception of the alternator are factory. So the block, crank, pistons, rings, and heads (i think) all have about 60k on them the rest of the truck has 163k. So its probably due for a little TLC anyway.

I want her to run smoothly. I bought this for my wife to learn to drive in. When you let off the gas and it runs so rough you cant push the brake pedal is a risk I am not ready to take with my wife, so I am just going to replace the works.

 

Looks like a small project. Taht carbon build up is pretty normal, although the one area does look a litle clean. Do the presure test to see if your poppoff hoses are leaking under pressure.

Keep the pics and updats coming.


My first thought was a vacumm leak.

 

Going to feel stupid if it is a Vacum leak! I found a spider, nut kit, and plenum gasket on E-Bay last night, $314 later, it should be here in a few days. Another forum I post to, people ae telling me to replace the lower intake gasket as well while I have it apart, as this engine is notorious for leaking. But with all the carbon in the plenum and EGR, and the rich reading, and the clean spot someone mentioned in the plenum I think it needed replaced anywho. Vacume hose is cheap I will probably replace some while I have easy access with the intake off.

 

More pics

 

Were having fun now. [8D]

She pooks pretty good for that many miles.
Keep em coming.

Its a great idea to repalce the lower intake manifold gaskets too. Make sure you get the big glops of RTV on teh corners. If you got the coin, now it a great time to replace the oil pressure sending unit. Its a real bear with the intake manifold back in the truck.