mojopony

My code scanner is detecting a thermactor problem on both banks and insufficient EGR flow. Its probably due for a new EGR valve, although the present one is not really that old. The codes I got were 314, 311 and 332 in that order whenI did the KOER (key on engine running) test. The KOEO (key on engine off) only showed the 332 code for the EGR valve. Any advice or info would be greatly appreciated.

mjr46

you'll need to check the evr selonoid to see if it is opening during the test to allow vaccum to pass through the selonoid to the egr valve to open.....first you can check your vaccum supply to the evr selonoid to make sure it has vaccum then T a vaccum gauge between the egr valve and the selonoid and re run the koer test and watch for vaccum to be applied to the egr valve if it doesn't...... work your way back to the evr selonoid and using a test light back probe the connector ( using a wiring diagram see if the evr is turned on by the ecm via applying a ground) if so then make sure supply voltage to the evr is present if so hook the test light end to 12 volts b+ and the other end back probe the neg side of evr selonoid and re run the koer and when the egr portion of the test is run the test light will light.......if it does light and no vaccum is present to the egr valve then the selonoid is bad...replace and re test.......make sure egr passages in intake are ckean and not plugged ....you can test this by applying vaccum directly to egr valve... if it works and passages are clear the motor will start to run rough and or stall!!!

mojopony

Thanks for the reply. I'll do some poking around with my test light and vacuum gauge and see what happens.

mojopony

I tried applying vacuum to theEGR valve and the idle speed decreased quite a bit so I'm assuming the EGR valve is okay and that the passages are clear, well relatively at least. It started raining here in NJ so I had to call it quits for the moment. I'm suspecting that I've got a vacuum leak somewhere. It would be kind of a coincidence if the TAB/TAD & EVR solenoids all went bad simultaneously. Plus I would think that I'd be getting different codes, but I'll check the solenoids anyway. I forgot to mention in my original post that a I get a 511 during the KOEO test, but I seem to remember that the chip causes the ROM test to fail. I'll poke around some more after the rain lets up.

mojopony

I did a little more checking around with the vacuum gauge and I've got zilch at the EGR valve, but as I said if I apply vacuum manually the idle speed decreases. I have only slight vacuum at the TAB/TAD valves, maybe 1 or 2 inches at the most depending on engine speed. If I apply vacuum to the TAB valve I can feel the change from venting to the atmosphere versus not venting. The thing is though with all the stock vacuum lines connected it seems to always vent no matter what the engine speed is. It really blasts out some air at higher RPMs so I guess its safe to assume that the smog pump is okay. I tried applying vacuum to theTAD valvewhile keeping one hand on the valve, but I can't feel anything. I guess the next step will be to pop the large hose off and see if it actually moves under vacuum. I didn't do any electrical checks on the solenoids yet. All that stuff is buried inside the fenderwell. My manifold vacuum is good, but I don't know if those color coded plastic tubes are all good.