93 S-10 Blazer 4.3L Vortec Engine VIN W

The Following is New:

Injector, FPR, Nut Kit,

Replaced Heads from Junkyard
Replaced Transmission from Junkyard

it ran Fine for 30 minutes now it sputters when idling, runs with like a rough idle at higher speeds but doesnt stall while running on interstate, once it gets to low speeds or stops it will rumble and run rough and sometimes die. when at low speeds its gayish smoke that rises from engine and exhaust, when running down road its a blue fine smoke and engine has a rough running feel. it seems either too much fuel or oil one is going through valves/cylinders and it has a loss of power particularly in reverse also takes a while longer to shift.

anyone know the main things to check look at or a good guess at what the issue is? would valve seats do this?
Info:
Fuel pressure is Fine, no gas in oil

 

Valve seats can cause this issue, as well as many other things. Did you use new gaskets when you changed the heads? Did you check the heads/block to make sure nothing was warped and that the gasket would securely fit on both parts?

Blue smoke = oil being burned in the cylinders. One thing to start with will be to pull the plugs. With that much oil entering the cylinders, you should see remnants of the oil on at least one spark plug. That will tell you where to start.

 

Once The cylinder (s) is Located where you go from there?
Compression Check on cylinder?
If I have Low Compression on One cylinder then That would mean sticking rings on the cylinder(s) correct?
if that is the case then would "Restore" or other additives most likely correct the largest part of the oil leak.

While at work i had a family member Unreliable but all the same supposedly checked the compression on the passenger side, 125,95,85 compression from front to rear of motor, Blue smoke + Oil on Plug + Low compression on 2 cylinders = bad rings
Solution = New Engine (again) or rebuild this one for more cost or brand new engine $1500.
If there a diff possible solution please let me know

If Gas did mix with oil would it Thin enough to blow by the rings?

Gas was in Oil, ( smoke from exhaust worse when idling, Drained Oil and let drain plug stay out of truck and left filter off 2 days now) is it possible that adding new oil and plugs would fis the issue? or is more likely than not the damage is done

 

Not necessarily the rings .....

If it ran fine before the junkyard heads were installed, then those heads, or the gaskets probably have an issue.

 

Original Engine was replaced with Junkyard engine, The Junk yard engine never ran good The heads had to be replaced. After replacing heads the engine ran fine for 30 minutes and then went to smoking and sputtering. This was due to a bad injector, leaked gas into lower intake and then on into crankcase, replaced Injector-fpr-and fuel line o-rings, Now vehicle is not pouring gas in Oil but it will start fine , idle fine, then if run a bit hard a while then slow down to turn off ot come to stop it looks like your setting off napalm with so much smoke. How long will it take for rings to seal again after gas oil mix was run through engine? is the most likely cause of smoking where the gas thinned oil down enough to blow by the rings and also dowling plugs?

Oil has Been changed
New Plugs are being added ( cheap champion plugs)
added rislone restorer

 

Id Use delco ignition products these engines are picky for ignition products

 

Usually if it smokes at idle, but not under power (constantly) then the valve seals have dried up/cracked ... or the valve guides are worn to the point that it wipes them out.

It could very well be the rings too. Gas washes oil off the cylinder walls, & they'll wear out real fast if the oil is left diluted. Fuel is a poor lubricant.

 

it idles without smoking, The smoke comes when coming to a slow down or stop following driving, when the gas is goosed while idling it throws puffs of smoke.

 

Ok in that case could just be a bad PCV valve. When your slowing down, throttle closed, vacuum is at it's highest .... so oil is getting sucked in & puddling up in the intake during that time, from what you described. Then you hit the throttle & it gets sucked into the engine. The PCV valve is supposed to shut 100% at high vacuum.

It's a crap shoot trying to diagnose over the net ....

 

in deed But its a Good way to get info on here to look and I bet the pvc may be bad, I have serious vacuum leaks that cause some issues, i was not aware it caused that though Thanks Buddy