I have a 87 Toy 22ret, has been running fine, but today when I picked up the kids from school, the idle dropped slightly and ran a little rough. I revved it up to about 1500RPM and it automatically dropped down to 1000rpm and kept doing this for about 10 seconds. I let it go back to idle and tried it again at about 2000 rpm with the same symptoms as above. When driving home it did not do this the RPM stayed even and did not drop while moving. When I got home and revved it up while in neutral it did not do it again and it is again running smooth.
No codes, no smoke and no leaks, radiator is full and the temp is running within normal limits. Basic tune up incl plugs, OEM wires, cap and oil change. TPS was adjusted, I think, by me about a month ago and the timing was set with the jumper cable in place. Used sea foam last summer and really did not see a difference in mileage or performance but I did see alot of smoke for about 20 min. Then I found since I have a turbo it was probably not a good idea to use this stuff. Just what I heard.
So, if anybody can explain these symptoms to me that would be great.
Thanks JMach1

 

Maybe some crap went through the fuel lines?

 

I have the same problem with my 1990 5 spd 22re. It happens every couple months for like a week at a time. It really ticks me off can some one help us?

 

I would replace the fuel filter and see what happens.

 

Oh yeah, I did replace the fuel filter when I did the tune up.

 

Consider the AFM. I had similar symptoms in an '85 22RE about 2 years ago. They grew worse. Not sure why I focused on the AFM eventually, but I finally opened it up and found the phenolic under the swing arm which feeds back the position of the air gate in the AFM to be significantly worn. This lead to intermittent infomation which then gave wrong settings to the rest of the system.

After trying to fix it for about a year, I gave up and replaced the unit. No problems thereafter. Couldn't figure out how to resurface the phenolic, although I think it is possible, but the new one should last another 200kmiles.

There are fairly easy checks to make if you know how to use and ohmeter. Intermittent contacts are a bit tricky to detect, but you can if patient. Also, you can open the AFM and reseal it with Silicon Rubber if you want to be sure. The unit is not inexpensive, but you should be able to get one on Ebay if this proves to be the problem.