authoritah

I recently installed 4 new injectors along with new throttle body gasket in my Toyota pickup (1992 5 speed 4x4). The long block only has 24k miles.

It is running better, much more responsive, but now it is making a squealing sound. The sound is not coming from the belts or pulley, but closer up by the fuel rail and injectors. When I "stomp" the throttle the squeal/whine goes away for a second then comes right back. Any idea of what could be making the sound?

Could it be a vacuum leak or air leak somewhere? I'll continue to check vacuum hoses.

Before installing new injectors the engine made no squeal/whine or other odd noises. It seems to be running fine, just has a really annoying squeal.

authoritah

Not sure exactly what the problem was but here is what I did to fix the squeal/whine.

I had an extra intake gasket set laying around so I replaced the egr valve gasket, throttle body gasket, and gasket where the throttle body meets the lower intake. I checked and rechecked the vacuum hoses, replaced one small one that actually wasn't in too bad of shape.
Also slightly tightened the fuel rail bolts (maybe 1/16 of a turn at most). I made sure that the injectors could still be rotated freely and not bound up. Just remember there is no reason to be heavy handed with any engine components!!

As I was reassembling I progressively torqued everything to specs in the Haynes Manual.

Started it up and the squeal/whine was gone. My guess is that it was an air/vacuum leak somewhere.

Even though no one responded to this post I'd still like to thank YotaTech and all the great info they have on this site.