'87 22RE pinging with 2400 rpm idle

[E92FF]

I'm hoping someone here has experienced this before or that there is something common to these motors and somebody will point me in the right direction.

This truck is new to me so I don't know a lot about its history other than it wasn't used. When I test drove it it was pinging a little, nothing like now. I attributed it to old fuel or dirty injectors. Maybe plugs, nothing serious anyway. I topped it off with super and dumped a bottle of sea foam in the tank. I have burned 1/2 of that tank and the pinging had cleared up and it has been running pretty good. The one thing that has hung on was an occasional miss at idle.

So I was driving it this morning and a few issues developed.

1. I pulled up to a stop light and the rpm in neutral was holding at 2400rpm.

2. As I pulled away it was pinging really bad!

3. I shifted at about 3000 rpm and the tach went to around 3400 before falling.

It continued this all the way home. I made one stop and when in restarted the motor it idled smoothly at around 800rpm. As soon as I touched the throttle it went right back to 2400rpm and wouldn't come down.

Any ideas before I tear into this would be appreciated!

 

[E92FF]

I've discovered the reason for the high idle though I don't see how this could cause the pinging as it's not connected to anything. This thing is sticking and not allowing the throttle lever to return to the closed position. What is this and what is it's purpose?

 

[E92FF]

Well whatever the filter looking orange thing at the end of the vacuum line is removing it fixed the idle and shifting problem. It still pings but not like it was this morning.

Anybody have any idea what the piece I removed is or its purpose? I'll go by the dealer later this week and ask but I'd be interested if anybody knows.

 

[E92FF]

I never figured out what the orange thing was but the truck drives way better without out it so???

With the throttle problem fixed I have moved on to the pinging. I adjusted the valves and found that they were way tight! I also bought plugs, cap, rotor, and wires. I bought an air filter also but after opening the air box I found that the existing filter looked brand new so I left it. The plugs, wires, cap, and rotor looked ok too but I decided to go ahead and replace all of them.

That was all going smooth until I pulled the plug in cyl #3. It was tight all the way out and the new plug doesn't want to start. The treads look ok but I'm gonna pick up a thread chaser today and see if that helps.

If this doesn't get her purring I'm going to start looking at vacuum lines.

One nice thing, the previous owner kept up on the maintenance. Look how clean the valve train is!

 

[Night_Wolf84]

I'm surprised that nobody responded to this yet. I too have an '87 and like to know what that little orange filter-ish thing is too.
Mine refuses to idle up during cold weather and I found out that the idle air control valve either needs to be cleaned out or replaced. (can't replace the valve since they discontinued making replacements both OEM and aftermarket)