Have not performed vacuum test yet. Will tomorrow. And ECU has been reset after sensor replacements, all though a good drive cycle should re-acclamate the ECU.

 

shouldn't it relearn without resetting it?
I'm following this closely as my 96 is also still running like crap with no codes..I got it to pop a couple times yesterday though... I suspect I have a bad head...sounds like marbles rolling in a can on the drivers side valve cover area. I've also done the tuneup/ 02 sensor and cat recently.

 

Yes it will relearn with a drive cycle off around 200 miles from what I am told. Marbles in the vavle cover does not sound good. I do not have that problem. I will post what I find though.

 

OK, so I have acquired a smoke machine and will be performing this, this up coming weekend to rule out vacuum leaks. So I will post back. Thanks Mike.

 

Is it hooked up to the stock cat ? Maybe its clogged from the last motor

 

I think in the original thread I said the Cat was clean, but if not, yes it is clean. Thanks though. I am open to all comments. It could be something real simple.

 

Well I spent yesterday putting smoke into the engine and came up with nothing as far as vacuum leaks. Plenum is good. But here is what I noticed this morning, a lot of condensation on the dipstick. Really? Come on. So.....blown or seeping head gasket? Cracked head? No milk in the oil. I guess the next thing is a leak down test, and maybe run the engine and see if I have a lot of bubbles in the radiator. No significant loss of coolant. This truck is frustrating. I'd get rid of it, but I would loose my butt. Will let you all know what I find.

 

I guess I am wondering what you mean by no "significant" loss of coolant.

 

No loss that I can tell. Nothing noticable from the overflow bottle, or radiator. That I can see.

 

I wonder if maybe you have a valve not seating properly opening/closing incorrectly.. or at different rates..