vkrunner

Hello all,

I have a '94 4RUNNER 4WD SR5 V6, 192500 miles on it. I bought it used couple of weeks back.

The gas pedal feels hard so I thought let me clean the throttle body using the cleaner (STP throttle body cleaner, safe for Catalytic conveter). So I disconnected the air inlet tube to throttle body and while my friend is pressing the gas pedal I sprayed the cleaner and cleaned the body and plate with a tooth brush. I also sprayed liberally along the circumference where plate meets body. There is not lot of gum though. Once completed cleaning I wiped with cloth and reconnected tubes and started the engine. Engine was rough for about 2 sec. but I pressed gas peadl a bit and let it idle for about 2 minutes.

Now I think the engine is idling at about 1200rpm. When in drive and idling, it idles art 1000rpm. Before cleaning the engine idles at about 750 rpm in park.

Did I damage anything? What things shoould I check/do to bring the rpm back to normal? There is no problem in normal driving. OTOH, the gas pedal is little better now.

Thanks All.

4Crawler

iTrader: (3)

You might want to check the TPS, it is not too fond of harsh cleaners:
- http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml

If that is OK, just turn down the idle speed. You may now have more air getting through the TB at idle with the cleaning and it had been turned up before to compensate.

Mad Chemist

Idling at ~1200 is normal, at least for a 3.4 L V6, not sure about the 3.0. The higher idle may just be due to the fact that you now have a clean throttle body. What you're calling "normal" is probably on the low side with restricted air flow due to the dirty TB.

Rick F.

Say WHAT?!?!?! Neither my 3.0 nor my 3.4 ever idled over 750-800 rpm after warmup/no A/C...

Beartracker

1200!!!! .I agree with Rick F. on this one. Mine is only a 2.7 but my friend has a 3.4 and none of them idle when warm , above 750.
4 Crawler gave you good advice. It sounds to me like you just did a good job of cleaning it and now you have to do a little idle adjusting.Also make sure your air cleaner is new or like new.

boogyman

that's the first thing I thought of when I saw the title. I had just about the same issue.

vkrunner

boogyman, could you please describe me how you rectified your problem?

I disconnected the EFI fuse for couple of times so far. It seems to have slight effect - Now my the engine idles at ~1000rpm but is not cosistent. It idles at 1100 - 1200 rpm at times.

Does disconnecting positive battery terminal will have any effect?

Also in general the engine seems to rev higher. The tires I have are 31x10.5R15 Cooper discoverer.

I have seen some posts in alt.autos.toyota that are exactly like the problem I have but solutions are not decisive/or I did not understand. The easy one I did is disconecting EFU fuse.

BTW, will the engine start if the EFI fuse is disconected?

Thanks a bunch guys.

4Crawler

iTrader: (3)

To turn down the idle speed, get a flat-bladed screwdriver and stick it into the idle air screw atop the throttle body. Screwing it in lowers the idle speed, out increases it. And I doubr the engine will run w/o the EFI fuse in, that is what supplies power to the ECU and the ECU controls the engine, including firing the fuel injectors and spark plugs.

Mad Chemist

My bad- I must have been delusional..after hoping in my rig I realized it was idling about 900 or so. Sorry about that...

MTL_4runner

That still seems a bit high unless you had the AC on.
Mine is very consistent and smooth at about 750-800 RPM

MTL_4runner

First check the TPS with a multimeter, then if all is ok I'd adjust the idle.
Someone may have adjusted it in the past to compensate for the TB getting dirty.

vkrunner

4Crawler,

Thanks for the continued support.

However, I could not find the idle air screw you are talking about. I took some pictures and they are here. Can you please let me know which one to adjust. Also, roughly, how many full screw turns are needed per 100rpm?

Thanks for all the help!!

4Crawler

iTrader: (3)

Not familiar with the 3VZE engine/throttle body. On the 22RE it is right on top of the TB. A Factory Service Manual for the engine should have the setting procedure.

tabb

Have you checked to see if anything is holding the throttle plates open? I've had bristles from the brush I was using fall off and jam in the plates.....

geneius

I had the same problem after my ISR mod and TB cleaning. So I adjusted the idle.
I think it's the screw in your second pic: https://www.yotatech.com/attachment....achmentid=6904

PWDR PG

4crawler: I have always thought on a fuel injected motor there was no easy way to adjust the idle speed because it is all governed by the CPU. The computer adjusts the idle there is no idle adjustment scew on a 22RE. If the idle is off i would think that something else was wrong. I had the same issue when I cleaned my Tb by the way. My idle speed went up, a lot durring cold starts as well.

vkrunner

Geneius, (nice nickname)

How shall I adjust that screw? Like rotate clockwise to increase or decrease the idle? Also any correlation between screwturns and ide rpm - meaning how many full turns are required for say 100rpm chage?

BTW, I DID adjust that screw - I turned about 60 degrees clockwise but that doesn't seem to effect the idle. I am afraid to adjust more so I returned the crew position back to original (as seen in pic).

Do you think I damaged the TPS with the cleaner solution?

Thanks.

90

That is the correct screw.
Just turn it with the motor running. You should reset the ECU ( again ) after you get it where u want it.

I have heard that TB cleaner can wick along the connector into the TPS... do the tests that MTL_4runner mentioned if you're suspicious. They're detailed in the Chilton's book that covers these years.

4Crawler

iTrader: (3)

TPS testing and adjustments:
- http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml

vkrunner

90,

Thanks for the info. I will attempt this procedure this evening.

When the engine is idling and if I turn the screw clockwise to reduce the idle rpm, does the rpm change AS I TURN THE SCREW or AFTER resetting ECU(by disconnectign EFI Fuse)? Also Any idea how much will be rpm change for one turn of screw?

Thanks.