sluggish acceleration

[SoCalN8Tive]

Just wanted to post an update on my "sluggish acceleration" status...problem has been solved...I went to change the plugs this morning and it appears that they were the original plugs. I have 97k miles on my T4R and after replacing them with 6 Denso plugs I purchased from the local Toyota dealer (part# K20HR-011) yesterday there's no issue with the acceleration. The install took me about 2 hours but saved a lot of money! Definitely would recommend this as a starting point for assessing issue in the OP. Good luck-

 

[Presumptive4Runner]

Hello, new member here resurrecting this thread since it's my main problem with my '05 V8 Sport 4R right now. I have about 175K on it, and after filling gas tank the past two times, I got the check engine, VSC TRAC lights on, along with sluggish acceleration at 30-50mph. It does eventually reach the desired speed, but there are times when I needed to speed up, stepped on the gas, and the thing would barely move. Not fun!

I had a mechanic replace all 8 spark plugs, as 2 were going bad, and that seemed to solve the problem until 5 days later when I filled gas tank again and the problem came back.

I bought a new gas cap thinking (hoping..praying) that this could be the main problem after seeing so many forums with people mentioning gas cap issues.

I do desperately need to get an oil change soon so that could be related but I'm thinking not as likely. My old gas cap was loose after turning a few clicks and then lifting off a little too easily. The O ring was a bit worn so I'm hoping this is really the only problem.

I may do the battery trick tomorrow to turn off the lights at least for now.

 

[Luke Earthwalker]

Hello all, new member here. I just picked up a 2004 v6 T4R. 192k miles. She seemed to run great in the beginning, but somewhere in between moving from Cali to New Mexico something went foul. When I floor it, it seems like she no longer wants to go into passing gear, like it's going into 2nd instead of 1st. I immediately changed the trans fluid and filter as well as the spark plugs. I can't seem to pinpoint the problem. Any ideas? Thanks in advance.

 

[m85476585]

Hello all, new member here. I just picked up a 2004 v6 T4R. 192k miles. She seemed to run great in the beginning, but somewhere in between moving from Cali to New Mexico something went foul. When I floor it, it seems like she no longer wants to go into passing gear, like it's going into 2nd instead of 1st. I immediately changed the trans fluid and filter as well as the spark plugs. I can't seem to pinpoint the problem. Any ideas? Thanks in advance.

Could the problem be higher speed limits? I don't remember the exact gearing, but 1st gear redlines around 30mph, and 2nd gear redlines around 60mph. If you are often driving 50-55 in California flooring it will go to 2nd, but at 60 or higher it can only go as low as 3rd.

Another possibility is altitude. Albuquerque is at 5,312 ft, so the engine has about 15% less power because it can take in about 15% less oxygen. Taos is at 6,969 ft, so about 21% less power. It's about 3% per 1000 feet. A turbo or supercharger can mostly compensate for it.

Another possibility is gas. At higher altitudes they often sell 85 octane as regular instead of 87. I've never had a problem running 85 at over 5000 feet in Colorado, but maybe it doesn't agree with your engine for some reason. I have had problems running 85 at lower altitudes by mistake. Some parts of New Mexico and Arizona are below 5000 feet, so be careful about filling up with 85 if it's available. It probably won't damage anything, but I've had bad fuel economy (22mpg in a Honda Civic on the highway) and reduced power as a result.

 

[Luke Earthwalker]

Could the problem be higher speed limits? I don't remember the exact gearing, but 1st gear redlines around 30mph, and 2nd gear redlines around 60mph. If you are often driving 50-55 in California flooring it will go to 2nd, but at 60 or higher it can only go as low as 3rd.

Another possibility is altitude. Albuquerque is at 5,312 ft, so the engine has about 15% less power because it can take in about 15% less oxygen. Taos is at 6,969 ft, so about 21% less power. It's about 3% per 1000 feet. A turbo or supercharger can mostly compensate for it.

Another possibility is gas. At higher altitudes they often sell 85 octane as regular instead of 87. I've never had a problem running 85 at over 5000 feet in Colorado, but maybe it doesn't agree with your engine for some reason. I have had problems running 85 at lower altitudes by mistake. Some parts of New Mexico and Arizona are below 5000 feet, so be careful about filling up with 85 if it's available. It probably won't damage anything, but I've had bad fuel economy (22mpg in a Honda Civic on the highway) and reduced power as a result.

Thanks for your response. I don't believe it is an altitude related issue. I lived in Taos 3 years ago and had a 2012 Tacoma at the time (same parts under the hood) and never had this issue. It's like it just doesn't want to go into 1st, whether I'm accelerating from a stop, gunning it from 2nd/3rd, or passing on the highway. Any other suggestions? Thanks again.

 

[Luke Earthwalker]

EDIT: The MAF sensor is in great shape, as well as the intake valve and all air filters (including cabin filter).

 

[Atlanta_man]

Head gasket ?

 

[m85476585]

Drive around 15-20mph and try putting the shifter in second and then first and see if the RPMs increase as expected when you shift to first.

It will never go into first at highway speed, so it probably isn't a problem with that gear alone. Try manually shifting to 2 or 3 on the highway, depending on your speed.

Have you tried things mentioned previously in this thread, for example have you checked the transmission fluid level? Have you put in new spark plugs recently? The V6 calls for them every 30,000 miles (which is a bit excessive, but they do wear out eventually). It would have been easy for the previous owner to neglect that.

 

[Mentor1880]

EDIT: The MAF sensor is in great shape, as well as the intake valve and all air filters (including cabin filter).

After cleaning my MAF it work perfectly, the sluggish movement stopped