1991 Hesitation...?

[yotatechie04]

Okay, I'm not exactly sure about everything on this truck, it's my best friend's and we've been doing quite some work on it here in the past month or so. It's a 1991 Sonoma, 2.5 I4 (I think.), We've just recently done all of the following to the engine:

-Rebuilt carb (TBI)
-Replaced intake manifold gasket
-Replaced valve cover gasket
-Replaced spark plugs, wires, distributor, and rotor button
-Replaced exhaust manifold
-Replaced O2 sensor
-Replaced EGR valve and gasket

So the problem is that the truck will run okay until it gets to normal operating temperature, after that, any speed above idle will cause it to cough and sputter, it backfires, blowing out some serious sparks and fire out the pipe once you stomp on the gas after it starts sputtering, and throws lots of black smoke. We've also discovered a "ticking" sound under the hood when the truck actually gets to normal operating temperature. As the idle decreases, the ticking gets louder. It sounds as if it's coming from the rockers or lifters...(not too sure, all I know is it's coming from inside the valve cover.) We have no clue about any of this, it's got us completely stumped. He actually attempted to blow it up today because he was so irritated with it after all the work we'd done. But anyways, any help would be greatly appreciated, so thanks in advance.

[JoNeZ3]

sounds like you waisted alot of time doing all that when you need to pull the head or valve cover and go from there, could be a bad spring and valves aren't seatin or whatever

91 I would pull the head, check everything, give a valve job, hone the cylinders and then I would feel safe

[yotatechie04]

Most of the stuff we replaced pretty much needed replaced anyways, it was throwing oil and stuff like crazy before. We've got the hesistation taken care of earier today, now all we need to do is work with the head to get that ticking to go away. Thanks for the info.

[JoNeZ3]

ahh ic, gl

[yotatechie04]

We'll be tearing into it sometime later on in the week...thanks...we're going to need all the luck we can get.