First, thanks for the suggestions as to why my 88 4Runner (22RE)ran poorly when cold. I am still investigating. But the investigation is on hold, because while driving home today, I heard a loud BANG, followed by a consistent loud noise in rhythm with the engine. It still ran, so I drove a few feet until I had to stop in a line of cars for a stop light. As I came to a stop it stalled out. I was able to use the rest of my momentum to turn into a parking lot. The engine bangs rhythmically and will not idle, but with gas it seems able to move. The bang seems to be air escaping, as the truck does not shudder violently with the noise. But I dare not run the engine to pinpoint the offending sound out of fear of destroying it. I did find a shard of a belt sitting near the driver side wheel well. All the belts behind the radiator are in tact and the manual says I have a timing chain, not a belt, so my first suspicion of breaking a timing belt seems incorrect.
I realize the near impossibility of diagnosing such a problem based on this description, but any ideas? As far as I know, the belt shard is not coincidence, but the cause of the problem.
The truck is a 1988 22RE Automatic 4Runner
Thanks for any help, or humorous jabs at my ignorance of engine mechanics.

 

umm....rod knock?

 

No jabs from me

As I have no clue...
Sorry to hear...and good luck

 

I would say start it one more time and take a good video with good sound quality; chances are if you still ran it long enough to hear and describe the noise, the damage is already done...

take plenty of pics too, and post em up...

 

maybe a backfire and blew one of the rubber boots on the intake duct?

 

Does it get louder as rpms go up? Does your truck idle lower now? Run poor? Losing oil? Make a vid or take a bunch of pics

 

hmmmm, rod bearing?