My 22RE started running terribly last week (I had been having ongoing issues with power and slightly wandering idle speed after removing the cylinder head and replacing the Timing Cover, Chain, disintegrated Guides, etc, but the truck was fine to drive). At idle it suddenly started sounding and running terribly. The engine sounds bad at higher rpms (higher pitched). It wants to stall really bad off the line, but drives pretty good above 2000rpm.

Checked TPS and it appears okay, but the R vacuum port on the throttle body does not have vacuum at 3,500rpm.

I sprayed some carb cleaner around the engine bay and at specific vacuum lines and noticed a difference in the tone of the engine, but not otherwise in how rough it's running.

The number 1 and 3 spark plugs look normal, just brown and dirty, but 2 & 4 look too white (pictured).

The Timing is at 5* BTDC.

Attached are a picture of what the #2 and #4 spark plugs look like, and a here's a link to a video of what the exhaust sounds like at idle.

Any thoughts on how to proceed? (Thanks for reading!)

 

Did you fix the vacuum leak(s)?

 

I haven't located the vacuum leak yet, if that is what the problem is, and I'm wondering if this could be caused by something else failing.

Could a vacuum leak get so dramatically worse so fast?

 

I'm really just hoping someone will listen to the video and go, Ah, that sounds like something I've encountered myself.

And I'll ask again, has anyone had a minor problem that suddenly got dramatically worse that turned out to be a vacuum leak?

 

I would go down a list. Easier things first.
#1 fix the vacuum leak.
Other possibilities.
Check the plug wires at night to see if you can see them sparking on anything. Check cap and rotor for cracks or just normal wear. Also consider the possibility of bad gas

 

Keep posting on what you've tried and what you find.
Undoubtedly you'll help someone out.

 

Ditto on bad gas. Amazing what watery fuel can do. I once filled up at a crappy Valero and my 8.5:1 20R started running like crap. That thing could almost run on pee, that's how bad the fuel was. I spent an hour screwing with it to try and figure it out. Next fill at a Shell, problem magically solved.

Had this problem on my carbed engine. A 22RE still has a distributor. The springs on the mechanical advance get weak and it screws the pooch on idle tuning. Once full mechanical advance is reached (about 2k-2.5k RPM) the running issues magically go away. Pull the dizzy cap and twist on the rotor. If it's sloppy there you go. If it's tight and has resistance the whole way to full advance it's probably not your issue. Your exhaust sound also mirrors that theory. Not trying to get your hopes up but it's an easy to overlook problem.