Rough Idle/Black Smoke

M

mcd

New member
I have a 98 SR5 V6 that is idling pretty rough and throwing out some black smoke every now and then. I rarely drive this truck and have been meaning to work on it for a while. This past weekend I cleaned the MAF sensor, the throttle body and IAC. I had not heard about the O ring throttle body gasket previously but saw it mentioned on some forums so I haven't reassembled everything yet. I have tried to find the O ring gasket but any places that have it are charging $30+ for it. Is there somewhere I can find it for a reasonable price?

Do you guys think I should replace my O2 sensor(s?) while I'm at it? My truck has 85k miles on it (I bought it at 67k) and I doubt they have ever been changed.
 
Register to hide this ad
mcd said:
I have a 98 SR5 V6 that is idling pretty rough and throwing out some black smoke every now and then. I rarely drive this truck and have been meaning to work on it for a while. This past weekend I cleaned the MAF sensor, the throttle body and IAC. I had not heard about the O ring throttle body gasket previously but saw it mentioned on some forums so I haven't reassembled everything yet. I have tried to find the O ring gasket but any places that have it are charging $30+ for it. Is there somewhere I can find it for a reasonable price?

Do you guys think I should replace my O2 sensor(s?) while I'm at it? My truck has 85k miles on it (I bought it at 67k) and I doubt they have ever been changed.
Click to expand...

I wouldn't bother with the rear until you need to, it is still unknown if it affects fuel trims at all. The front you can change if you want, you can find the DENSO OEM sensor on Amazon for about $50. I would fire it back up before changing the sensor.

Have you checked your spark plugs at all? If it is still spewing smoke might be good to pull one or two and take a look and see if there's any signs pointing to what is going wrong. Usually black smoke = too much fuel.
 
gamefreakgc said:
I wouldn't bother with the rear until you need to, it is still unknown if it affects fuel trims at all. The front you can change if you want, you can find the DENSO OEM sensor on Amazon for about $50. I would fire it back up before changing the sensor.

Have you checked your spark plugs at all? If it is still spewing smoke might be good to pull one or two and take a look and see if there's any signs pointing to what is going wrong. Usually black smoke = too much fuel.
Click to expand...

Thanks for the reply. I changed the plugs about 15k miles ago. I'll test it out after putting it back together and see. The air filter was filthy if that has anything to do with it.
 
When you changed your plugs, did you change wires also? 20 year old wires are likely not in great shape anymore, even with only 85K miles. BTW, pretty sick owning a 3rd gen with such low mileage. Besides the 1st gen, the 3rd gen is my favorite even over my 5th gen as much as I love it.
 
2016 4Runner SR5 said:
When you changed your plugs, did you change wires also? 20 year old wires are likely not in great shape anymore, even with only 85K miles. BTW, pretty sick owning a 3rd gen with such low mileage. Besides the 1st gen, the 3rd gen is my favorite even over my 5th gen as much as I love it.
Click to expand...

No I didn't even think about replacing them. I'm hoping just cleaning the MAF, TB and IAC will fix my issue.

Does anybody know anything about the O gasket? Why the hell is it $30+ everywhere? My stealership wanted $61. Is it worth $30? Is there another place that has it at a normal price?
 
mcd said:
No I didn't even think about replacing them. I'm hoping just cleaning the MAF, TB and IAC will fix my issue.

Does anybody know anything about the O gasket? Why the hell is it $30+ everywhere? My stealership wanted $61. Is it worth $30? Is there another place that has it at a normal price?
Click to expand...

Would be a good idea to change the plug wires either way. Cheap peace of mind after 20 years. Is the gasket you're after just an o-ring? Try Rockauto.com for the o-ring, wires, whatever else you may need. Best prices I've ever seen.
 
2016 4Runner SR5 said:
Would be a good idea to change the plug wires either way. Cheap peace of mind after 20 years. Is the gasket you're after just an o-ring? Try Rockauto.com for the o-ring, wires, whatever else you may need. Best prices I've ever seen.
Click to expand...

I'm referring to the O style throttle body gasket they used for the supercharged 4runners. Part # PTR29-60030.
 
Looks like about $30 is the going rate. Seems like a lot for a gasket but it'll be there for the rest of the trucks life. Is what it is!
 
mcd said:
I have a 98 SR5 V6 that is idling pretty rough and throwing out some black smoke every now and then. I rarely drive this truck and have been meaning to work on it for a while. This past weekend I cleaned the MAF sensor, the throttle body and IAC. I had not heard about the O ring throttle body gasket previously but saw it mentioned on some forums so I haven't reassembled everything yet. I have tried to find the O ring gasket but any places that have it are charging $30+ for it. Is there somewhere I can find it for a reasonable price?

Do you guys think I should replace my O2 sensor(s?) while I'm at it? My truck has 85k miles on it (I bought it at 67k) and I doubt they have ever been changed.
Click to expand...

I have experienced similar issues in the past and it turns out it was the TPS (Throttle Position Sensor). When it goes bad, the engine runs rough. Simple fix but I highly recommend an OEM TPS!!! (Don;t buy aftermarket) and be sure to disconnect the battery when installing...
 
BamaDrewski said:
I have experienced similar issues in the past and it turns out it was the TPS (Throttle Position Sensor). When it goes bad, the engine runs rough. Simple fix but I highly recommend an OEM TPS!!! (Don;t buy aftermarket) and be sure to disconnect the battery when installing...
Click to expand...

Just to continue this thought, know that the TPS is spring loaded so if you decide to pull it off to see if it is causing the problem, it's difficult to get it back on in the right position or the engine will either idle high or fall flat on it's face when you press on the gas.

Normally a bad TPS throws a code but not always. The TPS was a common culprit on the 2nd Gen 3.0L engines for phantom problems.
 
You must log in or register to reply here.

Members online

No members online now.
Total: 186 (members: 0, guests: 186)

Forum statistics

Threads
278,309
Messages
3,554,071
Members
248,016
Latest member
Advally Service

Share this page

Trending content

Back
Top