smaxx.manimal

Hey,
I know that there are too many threads on intakes already, and believe me I have read a ton of them. I thought it would be easy to take apart my Throttle Body for a good cleaning and put it all back together. It was! Unfortunately, after trying to run it the dang thing started to just surge idle. (stayed around 1500 and reved to about 2000 over and over... vroom...vrooom...vroom...vrooom)

Its really quite abnoxious.

So I got mad, took it all apart again, got some new hoses, cleaned even better, let it all dry out again, topped off the radiator fluid, checked all my connections and tried to bring it back to life.

It WORKED!!! for about 20 seconds... then it started to surge again.

So then I tried moving the throttle position sensor, which did not help anything. then i tried the idle screw, again, nothing.

What is causing my idle surge? I think it may need a new sensor but I dont have $85 to throw at this thing right now if its not the definite answer.

I need to get this truck running by tomorrow night so I can take it to town and get my new tire mounted. I really want to take my lady friend camping this weekend before school starts...

Recap: 1989 toyo pickup (4x4 normal cab) with a 91' 22RE
Things were running well (though idle was finicky) until I cleaned the throttle body. engine will only surge in an idle, pressing the throttle only makes the surging happen with a different noise but wont rev up.
Help!
Thanks in advance, Im ready for round three with this thing but totally stumped.

myyota

When you cleaned the throttle body did you get any of the cleaner in the TPS ?, is so then its probably bad. When you put the throttle body back on the intake did you use a new gasket ?, if not you could have a vacuum leak. Are you sure all of the vacuum hoses are properly hooked up ?. You can`t adjust the TPS by loosening the screws and turning it, if you did that, its now out of adjustment, and you will need a volt meter to properly readjust it.

BigSwole

I got the same surging the first time I did that as well. I had set the metal tabs that are on the intake part, on top of the moving part of the tps, when i would crank it up it would rev really high then back down and try to cut off then do that again over, and over, and over.

Check your tps out really good. If your having a hard time adjusting it with it still on the intake, you could also remove the whole intake and adjust it while it is off the truck. This would also be a good time to clean it up really good.

If your not down with taking the intake off to adjust it then you can remove the thermostat housing, it helps gain access to the hard to reach screws.

My biggest advice is to replace the 2 screws with allen head ones from a hardware store. I just took one of the screws out and went to ACE Hardware, matched up the pitch of the thread, with a screw that had an allen head. It allowed me to use the allen wrench to get to it a little easier.

Stuwy123

iTrader: (1)

I had a very similar issue with my idle surging.
Are you losing coolant (even a little), no heat in the cab?

It turned out that my coolant system had a bit of a leak and was letting air in and they were reaching the IAC valve.
Check your coolant lines below the intake manifold for a leak. I had one hard line off the water pump and two soft lines. Check them both for leaks, easiest way is to check from the floor looking up.
My leak came from my block heater shorting out and burning one of the coolant hoses. The leak wouldn't spring until the engine was hot and revving high enough to push the coolant out the hole in the coolant line.

Stuwy123

iTrader: (1)

It is driveable with surging idle, makes things a little annoying if you engine break and/or the roads are icy. Hahaha, everyone around in traffic must've thought I was idiot, revving my engine all the time, then jerking engine braking and spinning tires off and on on the ice.

MudHippy

So...

The FSM engine troubleshooting section states under "Poor Driveability; Surging"

It wouldn't hurt to check that the TPS is functioning and adjusted correctly. It also wouldn't hurt to make sure there's no air in the cooling system. That could mess with the IAC valve and the ECT sensor, which could cause the engine to display strange behaviors.

Also make sure the accelerator cable isn't sticking. The fact that it won't rev up leads me to believe that the throttle valve isn't actually opening as it should, or the throttle valve is sticking part way open/not closing. So try operating it by hand to see if that's the case. Check to make sure it fully opens and fully shuts smoothly.

Here's the FSM, it has all the info you need to inspect the throttle body and to check and adjust the TPS.
http://personal.utulsa.edu/~nathan-buchanan/93fsm/

ToyMachine88

mine did the same thing almost every time i cleaned my throttle body, I found the reason mine was doing the loping idle was either the gunk that comes running out or the overspray of the cleaner getting inside the TPS hole. So after i clean my throttle body i take mass airflow sensor cleaner that is TPS safe and spray it directly into the TPS hole for like 2 seconds and i havent had the problem since. The hole is on the other side of the TPS on the inside of the throttle body. Might not be the same problem your having but it works for me. Just be careful not to get throttle body cleaner inside your TPS hole and use the MAF cleaner in a short spurt from the edge of the hole and when you start the truck rev it up good to burn off that extra fluid and vapor, take it for a quick spin and then check your throttle body for any gunk that might have came out late and is pooled up at the opening. Good luck

MudHippy

I never had a similar problem as far as the surging with mine. But for the first year I owned my truck the TPS was fouled up to the point that it wouldn't close all the way, and was giving me a constant code 51. Then one day I went ahead and removed it from the throttle body to see if I could fix it. I've never shied away from tearing things apart(even things that you're "not supposed to"). So, I carefully pried the metal lid off, without breaking any of the plastic tabs that hold it on(yes, it can be done). It actually wasn't untill then that I fully understood what was wrong with it. Like I said, it was pretty fouled/gunked up internally. I got the insides all cleaned out(used my special electronics cleaning juice, a.k.a. 99% rubbing alcohol), put it back together, and now it works just as good as new. Haven't had a lick of trouble with it in almost 4 years since. Tricky technique requiring a steady hand, but also highly effective. If all else failed, I figured I could just epoxy the lid back on, but there's no need to if you're careful enough.

BigSwole

WTF are you talking about?

read here...
https://www.yotatech.com/forums/f116...83/index2.html

or if you dont want to click ill quote for you.



i was telling him the same problem i was having and what i did to fix it, adjusting the TPS is a PITA and getting to it with everything connected is aggravating in the highest degree. Taking off the thermostat housing allows you easier access to it. but its equally aggravating having to put it back on to crank the truck up to see if you got it right....

i went through the same problem, i had in installed wrong. when i would crank it it would rev up then back down and almost die. All i had to do was adjust it correctly.



To the OP, check out your tps, i had huge problem with it, your tps controls alot more than just your idle, it is a huge factor on these trucks. when my truck was doing that, i had the little metal tabs sitting on the plastic part that moves on the inside of the tps. If you need any help pm me and ill try to help you as best i can.

vital22re

iTrader: (2)

My vote is wet/ dirty tps.

MudHippy

Gotcha. My bad. I thought you were saying to adjust it off the truck, as in take it off the throttle body and then adjust it. I wasn't thinking about taking the throttle body off to adjust the TPS on the bench. I get that. I've never felt the need to, but I can understand why someone might.

I apologize.

However, I still can't figure out the "Well rev up them off or almost off." part. But whatever, I'm sure it wasn't that important.

BigSwole

Its cool,

i was on my blackberry at work, and trying to type, what i was trying to say was,

when i was adjusting mine i accidently put the metal tabs on the moving part of the tps and when you would crank it up it would rev reeeealy high then drop back down and try to cut off, then over and over and over.


I just went back and edited my first post, i didnt realize i had so much mumble jumble on their. The autocomplete on the BB can be aggravating sometimes. i couldn't even understand what i had typed.

BigSwole

hey smaxx did you get it figured out?