92 Tacoma check engine light, rough idle, shakes like a blender

I've got a 1992 2.4L 4cyl Tacoma that shakes like a blender at idle! The check engine light is on constantly, but I'm not sure if you can pull codes on this year. Miss most apparent when at idle (really bad), almost goes away when A/C is engaged, or when TP sensor is disconnected. Really embarassing when sitting at lights and shaking all over the place. Any help would be greatly appreciated, thanks in advance.

Reply to
jay rafail via CarKB.com
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About half of the ECU codes stored on the first & second generation EFI Toyotas don't show a constant blinking check engine light therefore you must pull the ECU codes and auto tranny computer codes to see if a fault is registered. To pull the ECU codes:

All 1980-1995 and including 1995 EFI equipped vehicle allow you to find engine and related faults by pulling the ECU (computer) codes without the need for a handheld OBDII diagnosis scanner,the sites listed below have the fault codes needed to pull the codes and the instructions on how to do it:

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Pulling the ECU codes is the first thing I do to diagnosis a problem thereafter I reset the ECU to see if the same problems show up and if so I then take voltage measurements both with the engine running and not and compare with the factory service manual,I also close the ignition switch after a cold engine and also after a warm engine and compare them with the factory service manual.This technique will completely isolate your problem without having to do trial and error and it is the technique I use when repairing tv's,vcr's,home/car audio.

Any Public Library in your area would have the Factory service manual,Haynes,Chiltons,Mitchells,Clymers,Bentley and Toyota repair books.

There is also free AutoZone service manuals at:

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For scanned pages of factory service manuals for other engines:

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2003 Toyota Tacoma Factory Service Manual:

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FSM (factory service manual)can be acquired in several ways:

Toyota Material Distribution Center

750 West Victoria St Rancho Dominguez/Compton,CA 90220-5538 USA Ph:1-800-622-2033 (outside CA)(M-F: 7-5 PST) Ph:1-800-443-7656 (inside CA) Ph:1-310-818-4630 (in or outside CA) Speak to Beverly or Deloris
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1)buy a used one off e-bay 2)some Toyota dealerships may give you one or sell it for $10-20 (used) as most Toyota dealerships don't repair many old Toyotas and no longer need the service manual 3)some public libraries sell their old books as they are not in demand any longer 4)some free buy & sell classified papers,websites and bulletin boards may have some used ones for sale 5)some junk yards may have one laying around 6)some Toyota specialty garages may have one laying around and no longer use it as the vehicle may be too old and those mechanics probably have so much experience that they could publish their own factory service manual with corrections and "real world repair tips" 7)if someone has the FSM maybe they could scan all of the pages and post it on a site for all of us to download or view.

Sidney=AE =99 Repairs tv's,vcr's,home/car audio out of my home E-mail: snipped-for-privacy@yahoo.com Dartmouth,Nova Scotia Canada

1985 Toyota 4-Runner,solid fr> I've got a 1992 2.4L 4cyl Tacoma that shakes like a blender at idle! The
Reply to
sidneybek

Ok, update. Just pulled codes. Received 21 and 41. 21 says it is for an 02 sensor, is that for the one before the cat or after it? And the 41 is for the TP sensor, but wouldn't that set it off if I disconnected it? thanks again for any feedback

Reply to
jay rafail via CarKB.com

Yes disconnecting the TPS would trip an ECU code and disconnecting your battery or 15 amp EFI fuse for at least 1 minute with ignition switch closed would reset/clear that TPS code. The front/exhaust manifold oxygen sensor is usually the one that fails first as the catalytic converter one usually lasts twice as long.Note: the oxygen sensor is replaced for free as stated in your owner's manual,see below:

To clean the throttle body remove the air intake hose and examine the intake and throttle body for excessive carbon build if found then buy a can of throttle body cleaner labeled "safe on oxygen sensors,TPS's and catalytic converters" do not use carb cleaner make sure your engine is fully warmed up prior to using as when the throttle body is hot it dissolves the carbon easily and quickly.The labels usually specify to park the vehicle at ground level (0 degrees,no inclination) and have the engine running but I disagree I instead park the vehicle on a hill facing down and shut the engine off and hold a rag below the lip of the throttle body and poor the stuff and use a tooth brush.

The oxygen sensor is replaced for free in the USA only when the vehicle reaches it's first 80 000 miles regardless of the age & number of owners as stated in the factory owner's manual in the maintenance section,some Toyota dealerships are reluctant to replace it for free if that happens contact the Toyota regional head office for your region where they will give your local dealership 48 hours to comply. On average the oxygen sensors should be replaced every 6 years or 100

000 miles or so which ever comes first as stated in the owner's manual,warranty booklet and factory service manual.

Symptoms of a bad o2 sensor are poor gas mileage,hesitation in acceleration,worse emmissions,and in severe cases after the stat opens the engine can no longer maintain stable 750 rpm (with manual 5 spd tranny) idle and the engine begins to stall. The 02 sensor is designed to function once the vehicle has warmed up which is about after 10 minutes where the thermostat begins to open at

190 degrees Ferenheit depending on thermostat then the vehicles ECU system enters what they call a "closed loop system" then the exhaust manifold's temperature reaches 400 degree Ferenheit (I think)that's where the sensor starts to do it's job which is usually when the thermostat first opens up then the oxygen sensor senses the ratio of air to fuel and sends a signal back to the ECU then ECU compensates by increasing or decrease the open time for the fuel injectors to pump fuel.So usually the problem of stalling shows up after about 10 minutes of driving or so.many folks think that the o2 sensor is bad but an exhaust leak can cause excess oxygen to enter the exhaust system thereby fooling the sensor into thinking there is too much oxygen,there are other problems that could cause it to give false reading such as a vaccuum leak.

If you discover that the o2 sensor is bad and it is not under warranty then from my/others experience/research purchase an o2 sensor in the following order:

1)Toyota (NipponDenso now called Denso) 2)Denso aftermarket (Same as original but sold aftermarket) 3)NTK (oxygen sensor division of NGK)

Available at:

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(10% shipping by Fed Ex)
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(free shipping with $100 & over)
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Note:Toyota has an organized numbering system which dictates that the first 6 digits of their 10 digit (5 digits-5 digits)part numbers represents the part # and the remaining 4 digits dictate country of origin,color code,trim package and so on not in that order as shown in the free Toyota EPC (electronic parts catalog) download at:

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Here is a post fellow poster (Todd) who posted it on another

4-Runner/Pickup discussion site about 2 years ago:

"There is a newer version of the EPC available for download.Similar in size to the older version (254MB and 220MB zipped files)I have them on my personal FTP server (not always running), and they are also on another FTP server.

Address and login for mine:

151.203.109.45 Port 21 Login: t4x4pickup Password: t4x4pickup

Address and login for the other (usually running 24/7):

ftp.lawvision.net

User: upload Pass: upload

Apparently they cover 1988 and up vehicles (I haven't unzipped mine yet).

Feel free to upload and download on mine.

Enjoy! Todd E: snipped-for-privacy@hotmail.com"

For version 1/2002 the passwords are:

Europe 02052311 General 02032511 U=2ES.A. 02022608 Japan 02071608

Here's the codes for the 01/2002 disks:

Europe 02022004 General 02022212 U=2ES.A. 02022608 Japan 01121209

Here are online Russian dealerships that place the free Toyota EPC catalog online to be viewed only:

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These are text/site language translation softwares:

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NGK has a powerfull oxygen cross reference software which cross references their different part #'s into either a single,double,triple or a quad wire o2 sensors so you may find 10 or so different part #'s for your 94 pickup and all you have to do is plug those part #'s into:

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and see which one is cheaper I think you will find one for as low as $60.The NGK cross reference software is:

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before you replace the oxygen sensor soak the 14 mm brass nuts with any of these deep penetrating oils several times for several hours:

1)PB Blaster 2)Liquid Wrench 3)Kroil Oil 4)Aero Kroil & Sili Kroil 5)Toyota Rust Penetrant or High Performance Penetrating lube 6)Rust Check

the first ones being the best,also if you decide you need new ones here is the Toyota part for the exhaust manifold (brass)nuts # 90179-10175 (14 mm socket)

Oh yeah,I bought a NTK (NGK) oxygen sensor for my 85 4-Runner and it came with a gasket and a genuine made in Japan black plastic tie wrap I don't know if the Toyota or Denso aftermarket ones come with a gasket but ask them before you buy them.

Sidney=AE =99 Repairs tv's,vcr's,home/car audio out of my home E-mail: snipped-for-privacy@yahoo.com Dartmouth,Nova Scotia Canada

1985 Toyota 4-Runner,solid fr> Ok, update. Just pulled codes. Received 21 and 41. 21 says it is for an 02
Reply to
sidneybek

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