on my 95 runner when i started it up and its already warmed up the RPM drop up and down up and down....like its not gettin enough gas or something. it ideals at 850 RPM but it will drop below 500 then shoot back up to 850-1000 its weird let me know if u know what it could be

 

Filthy throttle body?

 

Go to autozone and get a throttle body cleaner. Clean out your throttle body and see how it goes...good luck OH, search this forum for cleaning throtte body/

 

Oh, one more advise that worked for my Honda Accord 98 that had the same problem. I waited until I had half tank of gas...about 7 gallons left. I purchased two Chevron gas additives and poured it into the tank. I drove the car near empty. The gas additive work and my idle is near perfect. Once in a blue moon now I also add Redline fuel injector cleaner. It really makes a big difference. This is just my advise. I am no expert. I was told to do this by other folks on this forum..hope it works for you.

 

I'm wondering if your fuel filter is plugging up. If it's older than about 60K miles or 5 years, swap that puppy out. Throttle body cleaning is a good idea. Check for vacuum leaks also.

 

Definitely clean your TPS first...thats what caused mine, its a quick and easy thing to do. There is a write-up somewhere on here on how to do it. Just do a search, if you can't find it I can try and walk you through it.

Another thing to check would be the throttle body as other have said, next things are the obvious ones, plugs, wires, cap and rotor. If these haven't been done recently within around 10k miles you might want to go ahead and do them, that way you'll have new ones and you can cross them off the suspect list.

Try those things and let us know how it turns out for ya!

Fink

 

is it pretty easy to clean the throtte body

 

yup.
an old toothbrush, a rag, a screwdriver, and some carb cleaner. It will take maybe 15mintes.

check out:
http://4x4wire.com/toyota/maintenanc...tenancep5.html
https://www.yotatech.com/~corey/tech...b/haveblue.htm

or try a google search. there are tons of articles out there.

I had a similar problem (surging idle) on my '95 but it turned out to be low coolant due to a water pump leak. Check your coolant level and watch your temp guage.

 

who exactly would you clean it out?

 

Mine use to do that when I had the heater on in Park. I adjusted the Idle Up screw and no problem now.

Does yours only do this with the fans on ? Or all the time

 

my bad i didnt even see this thread and i just posted the same question. i'll look into my tbs tomorrow as well

 

its only does it sometimes. sometimes when i stop it will be at 2000 then sometimes when i stop it will be at 900 its weird

 

Sounds like a combination of either TPS or IACV. Clean the IACV first and throttle body. That was my whole problem...

 

TPS and IAVC what are they? and where are they at

 

Check for a vacuum leak.

On my '94, there is a "sensor" that goes connected to the power steering and has two feetings at the end which each recieve a vacuum line. One fitting is broken and therefore, there is only one vacuum line going into the sensor at the moment - the other vacuum line is dangling. Everytime I turn the steering wheel at idle, the RPMs drop to almost wanting to shut off the engine so I just add some idle speed and RPMs shoot to regular.

The "sensor" is one-hundred bucks from the stealer so I am just leaving this as a "some day" replacement item.

 

TPS is throttle position sensor...you have to check the ohms to make sure its good. 4crawler gives a good description for ya...http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml
The IACV is the idle air control valve. it is on the side of the throttle body and has a plate with 4 screws over it. take the screws out...you'll see a valve there now what I did was use a pair of pliers and pull the top of it to where you see a pin come up out of the valve. have a 2nd person squirt it with throttle body cleaner and wd40 while you let it back down and move it around to free up any carbon deposits on the backside of it. put it back together and that should be it.

 

Yea its probably a vacume line