Horrible Idle and Missing on 1985 4Runner

[EROK81?]

I recently bought a 1985 4runner with a recently rebuilt engine with maybe 5k on it, LC cam, Downey Header, etc etc. This is my first Toyota so I figure some of you have been through this already.

It has developed a horrible idle and major missing at partial throttle/compression braking. It's almost like a turbo car. Starting out in first it lacks power then at about 3k (almost exactly) it takes off with a very noticable increase in power. It also smells fairly rich. The worst is neutral throttle while moving, maybe one of the worst running vehicles I've driven during that part. The AC is mostly removed but some of the sensors seem to still be in place. I looked over the visible vacuum lines and they looked in good condition with no obvious leaks.

I apologize for making this thread so soon as I haven't really even looked it yet, but I am going to start on it tomorrow night so I am looking for some ideas to check. I've read a few things saying it could be EGR related?

On a side note - how well do Toyotas run with none of the emission stuff? I used to have a talon that I removed everything from and ended up with two vacuum lines which was nice. Is this possible on a toyota?

Cliffs: 1985 4runner runs like crap under 3k, a lot of missing at neutral throttle and decelerating, missing at idle, almost wants to die at idle, seems to run rich until I can get it moving and "clean it out."

Let me know if anything else will help.

Thank you.

 

[billylight]

sounds to me like the timing is way off like the the timing chain is not set right. but you say it developed this so you must have had it right at first? maybe it skipped? sounds like timing

 

[choptopbII]

Is it the 22r or 22re??

 

[EROK81?]

That's the first thing I am going to check. I swear it didn't do it when I test drove it, but who knows. Maybe it did and I was just too anxious to buy it so I didn't notice it.

 

[EROK81?]

22re

 

[4x4_Welder]

Bad intake tube (assuming it's a vane air), MAP sensor disconnected, bad TPS, possibly bad coolant temp sensor as well. It could also be the computer reacting poorly to the built engine, try pulling the EFI fuse for about two minutes and then put it back.
Also see if the vane air flow sensor has been tampered with, it might have been adjusted too far. The factory seals the top of the sensor with epoxy, you cut that open to adjust it then reseal with RTV. It's usually pretty obvious if it's been tampered with, people are usually not neat about their RTV application.

 

[Greg]

Bad intake tube...

That's where I would start...

My 4Runner with a 22RE had this problem, the intake tube tore while I was half way thru a trail. I duct-taped it back together and it worked fine again.

Those rubber intake tubes get brittle after time and a little torque, bounce or just about anything will tear that hardened plastic.

 

[Cruiser]

Check all your grounds!! have had that be an issue several times..

 

[EROK81?]

That's where I would start...

My 4Runner with a 22RE had this problem, the intake tube tore while I was half way thru a trail. I duct-taped it back together and it worked fine again.

Those rubber intake tubes get brittle after time and a little torque, bounce or just about anything will tear that hardened plastic.

This could be it.

The inner fenderwells are gone and the intake is just hanging out off to the side. I kept moving it a lot and leaning on it from time to time. A quick look at this morning it looked fine, but I'll check that out too. It's really the only thing that's changed.

I changed the top coolant sensor because the temp gauge registers half temp no matter what the actual engine temp is. Changing the sensor half fixed it. Now it works until it starts to warm and the gauge will move between it's halfway point and the actual temp until finally resting around halfway.

Grounds all looked fine, but I'll look them over again tonight.

 

[EROK81?]

Turned out to be the timing was way off - about 8 degrees. Oh and a massive PCV leak at the valve cover gromet. I am glad it was something so simple. Now it runs perfectly, no missing, and a nice smooth exhaust note.

Although...I noticed the frame is starting to crack. Looks like I'll be welding that this weekend.

Thanks for the help.