FNG here. I did several searches trying to find a related post but no dice. I picked this truck out of the backwoods a few weeks ago and am trying to sort it out. I cleaned the engine bay with degreaser before doing the clutch and trans. Now the engine wont rev past 1900rpm unless I hold the throttle wide open. It runs fine, idles fine and drives fine at low rpm. As soon as it gets to 1900, it shuts down like the key is turned off and comes back on at 1600. It sounds like its hitting a rev limiter? I cleaned and dried the dizzy and cap after the cleaning so I dont think its that. Any ideas would be appreciated.

 

Any chance you switched at least 2 of the plug wires around? Make 100% sure you got them right.

 

Didn't unhook the wires. Runs perfect other than the rpm limit. It used to have an erratic idle, now its 700-1000 rpm consistently.

 

Check your cam timing and your ignition timing. Low power is a clear indication of the timing being off.

 

Unhooked TPS and now it goes. Found a 1 wire connector off but I didn't have time to sort it out before work. Black wire with red dots. Also, no CEL with the TPS off.

 

Hooked the TPS back up a few days later and now it seems better. Still has idle trouble but driveability is much better. The no CEL with the TPS unhooked concerns me. If this thing is running in base map all the time thats not good. I dont know much about toyota electronics and I want it to run right so I'm thinking of going to a local toyota genius to sort it out.

 

I'd bet you got water in the TPS when you cleaned the engine. Same thing happened on my Datsun - same symptoms - it was aggrivating. Just unhooked the TPS, use a hair dryer to dry out connections on both sides, and hooked it up (with heat shrink tubing this time for water protection). It creates and artificial reading when the water gets in there, and makes the ECS think you're at redline, thus cutting gas - puts you in "limp mode".

 

Thanks for the post, I think your right. It seems to be getting better everyday, like it may be drying out! Its almost back to normal at this point. There is another sad decelopment, my used replacement trans now sounds like it has rocks in it in all gears except 3rd. Its waiting at work for AAA to bring it home so I can check it out. Not a good day for the pickup.