Not your normal rough idle
 

Attached may be an understatement, this 22-re engine has seen 130 K miles, many of which have been spent off road and in flooded conditions. I live in Duluth MN where salt and snow become your number one enemy... but that is not the problem. After the last head gasket replacement.... which was one oil change ago... i still am loosing coolant, not 100% sure from where, am continuing to get blow-back in the oil, and to top it off ... i have never felt a worse idle from my 4 banger.
So far, the alternator has been checked, the battery replaced, timing has been set back to factory settings ( cant seem to get the check connector shorted but nevertheless it starts right up) and the wierd part... The idle gets incredibly bad when the heater is turned on with combination of headlights, and aftermarker fog lights.
Doesn't sound like a vacum leak ... but when draw on the battery is high ... the engine idles soo low .. the brake booster gives out and a rock hard brake pedal surfaces.. So, fellow toyota lovers .. help me fix this .. because frankly im getting sick of this.

- :chair:

Check the TPS IDLe adjustment:
- http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml

Then check the grounds (engine bay and cab) and power wires, might be the cause of the rough running and low idle. Use a volt meter and check for excessive voltage drops around the engine bay and in the cab. Then if the above are OK, turn up the idle speed, might be the electrical load is bogging down the engine and it just needs a faster idle to run. I set mine around 900 and it works fine.

one last thing
 

the page that i was linked to said that the TPS can just plain wear out,
and this might be true ... but is it possible that the engine rebuild that included bored cyllinders, and the 3 times the head has been milled, have caused the TPS sensor to be off in comparison to cyllinder size and compression?

The TPS has no interaction with cylinder size or compression. It merel is there to tell the ECU what the Throttle Position is.

if your getting blow back in the oil you should try a compression or maby a leakdown test

Ok, I will try, how about a terrible PCV valve or grommet. Simple but why not.

I had a really bad, I mean nasty idel that got cleared up in stages. TPS replacement, helped. Replacing all vacuum lines, helped a lot. EGR was clogged, and stuck, replaced that too. Now I cant tell the difference between idle at a stop in D, or in N. (auto tranny) When I got it, idling in D vibrated my skull plates.

Okay, so i replaced the TPS and now the engine won't idle ... it accelerates and decellerates, then repeats itself without end. I tried adjusting the TPS forward and back a little bit at a time with no avail. NOTHING ELSE HAS BEEN TOYED WITH .. so help me out here.

Oh, and when i installed the TPS. I noticed one thing, the butterfly valve in the throttle body did not close completely like i know it should. Im guessing the new TPS caused this but i dont know how to fix the problem. The TPS won't adjust far enough back to get the butterfly valve to close. and whatever advice comes if at all possible... tearing the valve cover and thermostat off to get her off would be nice to avoid.

Adjust the butterfly valve so it closes fully (back off the throttle stop screw) then turn the screw in to contact the linkage and another 1/4 turn then tighten the lock nut. And adjust the TPS IDLe setting with an ohm meter as noted:
- http://www.4crawler.com/4x4/CheapTri...#TPSAdjustment

And replacing those philips head screws w/ allen head will let you adjust w/ the t-stat housing in place:
- http://www.4crawler.com/4x4/CheapTri...llenHeadScrews

fixed the problem there. The butterfly valve wasn't closing because, although the TPS cant be installed backwards, it must be turned clockwise until it sits properly against the TB. in any case, the idle is still as ÅÅÅÅty as ever .. and i was finally able to time the engine back to base timing and the engine dies. Wires were checked, spark plugs too.. and basically the only way i can keep it from dying is by advancing the timing close to 20*.
Still looking for a soloution to that rough idle. Can it be something to do with the brake booster? the brake pedal gets real hard when pressed halfway down, and ive seen a huge deterioration in braking capability. (brand new front calipers, properly bleeded brakes)

sounds almost like it jumped a tooth either on the TC or distributor....if you are advancing it that much....with a cam I am only advanced 4* over from stock.

Did you make sure to adjust the TPS as per instructions...
http:http://www.4crawler.com/4x4/Che...#TPSAdjustment

The TPS is a pretty sensitive device and needs to be adjusted just right to work.

i'll re-check the timing to distr. and cam sprkt. Will double check the TPS adjustment . And will get the f'in cherry picker out to pull that PCV vavle that hasn't been changed in god knows how long.

Here is how I pull the PCV valve:

http://www.4crawler.com/4x4/CheapTri...x/p1030238.jpg

http://www.4crawler.com/4x4/CheapTri...ne_Pix/25.html

Was an engine ground forgotten when the HG was done? High electrical load shouldn't effect the idle normally. If you cant find a missing/loose ground try running a jumper between the body and chassis, see if things improve.

ground... is there a ground wire that connects from body to chassis or body to engine besides at the rear of the head? i have a 3in lift and thus a hidden ground wire? any ideas?

[Hijack]
4crawler, where did you get the red vacume hoses?
[/Hijack]

good question ... thats a sweet, non performance upgrade.. like highlights for your engine

well.. here's the update. PCV valve came off, the cam timing is dead on, the distributor timing is dead on. The TPS is calibrated correctly (reading 0.89 w/ohm meter set to 20K, and .577mm of gap between stop screw and lever) Spark plugs checked, wires replaced, rotor and cap brand new.... and still a roughing really bad. once again ... this isn't your normal rough idle. Let me know if anyone needs anything to help pinpoint problem, any suggestions would be helpfull. (this roughing is gonna tear my engine mounts off the frame)

still could use some advice... thanks for the ideas