I have a 91 4runner 22re 5 speed 4x4. A while ago, I blew the motor do to a skipped timing chain. I picked up a used short block with about 100k on it, replaced the timing chain and headgasket, and then I put all of this back in the truck. It starts and idles cold well, but as soon as it starts to warm up, it won't idle on its own. I can manually hold it at about 900 rpms and it will idle. It also seems to be missing some power at higher rpms.

Things I have already looked at is the timing is close, new plugs, new wires, cap and rotor look good.

I'm running out of ideas on what to check next, and I'd like to get it going before the snow starts flying. Thanks in advance for any ideas!

Tom

 

Is the idle set screw properly adjusted? What I mean is do you have the warm idle set to 900rpm? I know on my rig the little O ring on the set screw was all hard and usless and my set screw would work it's way down as I drove around. The result was when I stopped the idle would be down around 200 or something and the rig would die. Check the set screw and see if that's it.

Just a thought.

 

it makes no difference where the screw is right now its allmost unscrewed

 

Timing and idle should both be set with the engine warmed up so if you're having a warm idle issue, either may be set improperly. If the screw is almost all the way out, you may have a vacuum leak somewhere or your timing is too far retarded.

With the engine running, grab a paperclip and short together the T1 & E1 terminals in the diagnostic check connector. The idle speed and timing should both noticibly change. First, adjust the timing to 5 BTDC then adjust the idle to 750, repeating as necessary since changing the timing will affect idle speed and vice versa. Once you're idling at 750 and timing is 5, remove the jumper and see how it runs.

Another thing you can check is the valve adjustments- .008" intake and .012" exhaust, with the engine warmed up.

 

well i have it idling where i want it and allwas had, it right about 900rpm it will idle until you hit the brakes then it drops to less than 500rpm and die shortly after if you dont hit the gas. also when i was adjusting it i got a code 43 which is gone now i have seen that code before the tc broke never found the cause tho