shimmy shimmy shake!

[wrigley123]

Hello,

2003 Tacoma mini 2.4 L automatic 62,000 miles. Just recently I am experiencing a drop in RPM and the truck almost dies out when at a stop. It happens very quickly and RPM jumps back up to normal. This is an intermittent problem and only seems to happen after the truck has warmed up. No other noticeable problems of any kind. Plugs were changed at 32,000 miles with stock plugs. No modifications of any kind have been done to this vehicle! Thanks

Wrigley

[Flash75]

I'm not sure if this will help but I would clean the Mass Air Flow sensor and the throttle body. See this link for how. It's listed under other maintenance.
http://www.4x4wire.com/toyota/mainte...tenancep5.html

Clifton

[wrigley123]

Originally Posted by Flash75

I'm not sure if this will help but I would clean the Mass Air Flow sensor and the throttle body. See this link for how. It's listed under other maintenance.
http://www.4x4wire.com/toyota/mainte...tenancep5.html

Clifton

Thanks Clifton

Mike

[wrigley123]

Originally Posted by Flash75

I'm not sure if this will help but I would clean the Mass Air Flow sensor and the throttle body. See this link for how. It's listed under other maintenance.
http://www.4x4wire.com/toyota/mainte...tenancep5.html

Clifton

OK Clifton......Mass Airflow Sensor is spotless, almost looks brand new. Throttle body also was very clean and displyed no signs of dirt or buildup of any kind. I did notice that the air filter was pretty dirty so I changed it. I noticed maybe a small change in the rough idle for the better, but i wouldn't stake my life on it. My next step should be to: Change plugs wires? Where to from here? Easiest/cheapest to hardest/most expensive! Thanks

Mike

[Flash75]

Mike, I'm still guessing on this, but I think I would check the EGR valve. They sometimes will clog with carbon. Instructions are in the 2003 shop manual, it's moved to;
http://misc.mmdsi.net/tacoma/tacoma-manual/
The EGR valve check procedure is in Volume II on page EC-13.
They suggest using a Vacuum gauge if we don't have the Toyota hand held tester or a scan tool. I missed your last post because I was on a family visit for 8 days.

Clifton

[wrigley123]

Originally Posted by Flash75

Mike, I'm still guessing on this, but I think I would check the EGR valve. They sometimes will clog with carbon. Instructions are in the 2003 shop manual, it's moved to;
http://misc.mmdsi.net/tacoma/tacoma-manual/
The EGR valve check procedure is in Volume II on page EC-13.
They suggest using a Vacuum gauge if we don't have the Toyota hand held tester or a scan tool. I missed your last post because I was on a family visit for 8 days.

Clifton

Thanks Clifton....I'll check this. I appreciate the help and know there could be numerous things/components causing this problem. The changing of the air filter did not cure the problem. Is it possible/probable that the EGR valve is just dirty? Do they have a history a being a high failure component? You and I have talked in the past. I am older than most on this forum. I use my my truck as my daily driver. I change the oil every 3000 miles religiously and take very good care of the vehicle. I changed the plugs at around 32,000 miles but have never changed the plug wires and the truck currently has 63,000 miles on it.

Mike

[Flash75]

Mike, Sorry about the EGR error. I assume you don't have a trouble code indication. All my previous fuel injected cars/trucks have been trouble free, so I haven't experienced idle speed problems. Looking at the shop manual it seems the Idle Air Control System controls the idle speed. You can see the information on checking the IAC on page DI 230 in volume 1 of the shop manual. It's
now located at;
http://misc.mmdsi.net/tacoma/tacoma-manual/
Trouble areas mentioned are; PCV hose connection, PVC hose, Open or short in IAC circuit, I would think not likely, IAC valve is stuck open or closed, Air induction system, ECM, I would think not likely. According to the shop manual you would have code PO505 or 511 if the idle speed continues to vary greatly from the target speed.
Maybe one of those indicators will be your problem.
BTW, The IAC is located on the throttle body on the firewall side.

Clifton

[wrigley123]

Originally Posted by Flash75

Mike, Sorry about the EGR error. I assume you don't have a trouble code indication. All my previous fuel injected cars/trucks have been trouble free, so I haven't experienced idle speed problems. Looking at the shop manual it seems the Idle Air Control System controls the idle speed. You can see the information on checking the IAC on page DI 230 in volume 1 of the shop manual. It's
now located at;
http://misc.mmdsi.net/tacoma/tacoma-manual/
Trouble areas mentioned are; PCV hose connection, PVC hose, Open or short in IAC circuit, I would think not likely, IAC valve is stuck open or closed, Air induction system, ECM, I would think not likely. According to the shop manual you would have code PO505 or 511 if the idle speed continues to vary greatly from the target speed.
Maybe one of those indicators will be your problem.
BTW, The IAC is located on the throttle body on the firewall side.

Clifton

Thanks Clifton, I really appreciate your help. I fiddled around with it on Sunday and couldn't find any cracked air lines or anything obvious. I went ahead and cleaned the throttle body with carb cleaner (even though it looked pretty clean to me). I pulled a couple of plugs and they look like they should be replaced. I will change the plugs this weekend and let you know if there is any improvement. Thanks again

Mike

[wrigley123]

I changed the plugs and the rough idle problem has seemed to have gotten a bit worse! The gap is correct on all plugs (0.43) and everything was connected back properly. I'm kind of at a loss as to where I should go from here!!!!!!!!